Earthquake Protection for Fire Systems

Revised May 1999Supersedes September 1998

Page 1 of 62

EARTHQUAKE PROTECTION FOR WATER-BASED FIRE PROTECTION SYSTEMS

Table of ContentsPage

1.0 SCOPE ..................................................................................................................................................... 41.1 General ............................................................................................................................................ 41.2 Major Changes ................................................................................................................................ 4

2.0 GENERAL ................................................................................................................................................ 42.1 Discussion ....................................................................................................................................... 4

3.0 RECOMMENDATIONS ........................................................................................................................... 53.1 General ............................................................................................................................................ 53.2 Sprinkler Systems, Including In-rack Sprinkler Systems and Small-Hose Piping Systems ........... 5

3.2.1 Sway Bracing ........................................................................................................................ 53.2.2 Flexibility .............................................................................................................................. 343.2.3 Clearance ............................................................................................................................ 383.2.4 Anchorage ........................................................................................................................... 423.2.5 Pipe Joining Methods ........................................................................................................... 423.2.6 Type, Attachment and Locations of Hangers ....................................................................... 433.2.7 Pipe Material ....................................................................................................................... 43

3.3 Standpipes ...................................................................................................................................... 433.3.1 General ................................................................................................................................. 43

3.4 Water Spray Systems ..................................................................................................................... 433.4.1 General ................................................................................................................................. 43

3.5 Foam-Water Sprinkler Systems ..................................................................................................... 443.5.1 General ................................................................................................................................. 44

3.6 Fire Pump Installations .................................................................................................................. 443.6.1 General ................................................................................................................................ 443.6.2 Sway Bracing ...................................................................................................................... 443.6.3 Flexibility .............................................................................................................................. 443.6.4 Clearance ............................................................................................................................ 443.6.5 Anchorage ........................................................................................................................... 443.6.6 Emergency Electric Power Supply Connection .................................................................. 45

3.7 Water Storage Tanks and Reservoirs ............................................................................................ 453.7.1 General ................................................................................................................................ 453.7.2 Flexibility .............................................................................................................................. 453.7.3 Anchorage for Tank and Foundation ................................................................................... 463.7.4 Clearance ............................................................................................................................ 46

3.8 Fire Protection System Plans and Calculations ............................................................................ 463.8.1 General ................................................................................................................................ 46

3.9 Examples of Sway Bracing Design ............................................................................................... 463.9.1 Examples .............................................................................................................................. 463.9.2 Gridded System—System No. 1 ......................................................................................... 473.9.3 Looped System—System No. 2 .......................................................................................... 533.9.4 Tree System No. 3 .............................................................................................................. 57

List of FiguresFig. 3.2.1(a). Lateral sway bracing using one vertical and one diagonal brace. .......................................... 6Fig. 3.2.1(b). Lateral sway bracing using two opposing diagonal braces. .................................................... 7Fig. 3.2.1(c). Longitudinal sway bracing using one vertical and one diagonal brace. .................................. 8Fig. 3.2.1(d). Longitudinal sway bracing using two diagonal braces. ............................................................ 8

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Fig. 3.2.1.2(a). Configuration A Fastener with two opposing diagonal braces−fastenersinto underside of structural member. ................................................................................... 19

Fig. 3.2.1.2(b). Configuration A fasteners with one diagonal and one vertical brace-fasteners intounderside of structural member. .......................................................................................... 19

Fig. 3.2.1.2(c). Configuration B Fastener with two opposing diagonal braces−fasteners into sideof structural member. ........................................................................................................... 20

Fig. 3.2.1.2(d). Configuration B fasteners with one diagonal and one vertical brace−fastenersinto side of structural member. ............................................................................................ 20

Fig. 3.2.1.2(e). Configuration C Fastener with two opposing diagonal braces−fasteners into face ofstructural member. ............................................................................................................... 21

Fig. 3.2.1.2(f). Configuration C fasteners with one diagonal and one vertical brace−fastenersinto face of structural member. ............................................................................................. 22

Fig. 3.2.1.2(g). Special threaded pipe fitting for attachment of sway brace to structure. ........................... 23Fig. 3.2.1.2(h). Detail of connection of sway brace to side of wood beam with through bolt. .................... 24Fig. 3.2.1.2(i). Dimensional locations for lag screws and through bolts in wood. ....................................... 24Fig. 3.2.1.2(j). Pilot hole sizing for lag screws−use with Table 3.2.1(c). ..................................................... 25Fig. 3.2.1.2(k). Examples of Bracing Attachment to Piping. ........................................................................ 27Fig. 3.2.2.2(a). Flexible coupling and four-way sway bracing details for riser. .......................................... 35Fig. 3.2.2.2(b). Arrangement of manifolded risers. ...................................................................................... 36Fig. 3.2.2.2(d). Arrangement of flexible couplings for risers passing through floors of multistory

buildings. ............................................................................................................................. 37Fig. 3.2.2.2(c). Arrangement of combination risers for ceiling sprinklers and in-rack-sprinklers/

hose stations. ...................................................................................................................... 38Fig. 3.2.2.4. Arrangements for piping feeding in-rack sprinklers. ................................................................ 39Fig. 3.2.2.5. Arrangement for pipe drops supplying sprinklers below ceilings, mezzanines,

walkways, etc. .......................................................................................................................... 40Fig. 3.2.2.7. Seismic separation assembly for fire protection system piping that crosses a seismic

building expansion joint above ground level (Source: Data Sheet 2-8N, fromNFPA by permission.) .............................................................................................................. 41

Fig. 3.9.1. Example of building with three sprinkler risers and three types of sprinkler systemconfigurations. ............................................................................................................................. 47

Fig. 3.9.2.1. Layout and zones of influence for lateral and four-way riser sway bracing forSystem #1. ............................................................................................................................... 48

Fig. 3.9.2.2. Layout and zones of influence for longitudinal and four-way riser sway bracing forSystem #1. ............................................................................................................................... 49

Fig. 3.9.3.1. Layout and zones of influence for lateral and four-way riser sway bracing forSystem #2. ............................................................................................................................... 53

Fig. 3.9.3.2. Layout and zones of influence for longitudinal and four-way riser sway bracing forSystem #2. ............................................................................................................................... 54

Fig. 3.9.4.1. Layout and zones of influence for lateral and four-way sway bracing forSystem #3. ............................................................................................................................... 57

Fig. 3.9.4.2. Layout and zones of influence for longitudinal and four-way sway bracing forSystem #3. ............................................................................................................................... 58

List of TablesTable 3.2.1(a). Weight of Water-filled Pipe ................................................................................................. 11Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members ........................................... 14Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members (Metric) ............................. 15Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members ........................................... 15Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members (Metric) ............................ 16Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members .......................................... 16Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members (Metric) ............................ 17Table 3.2.1(c) Hole Dimensions for Lag Screws ......................................................................................... 25Table 3.2.1(k). Minimum Shear and Tension Capacities for Concrete Anchors .......................................... 26Table 3.2.1(d). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular to

Grain, lb. .............................................................................................................................. 28

2-8 Earthquake ProtectionPage 2 Factory Mutual Property Loss Prevention Data Sheets

©1996 Factory Mutual Engineering Corp. All rights reserved.

Table 3.2.1(d). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular toGrain, lb. (continued) ........................................................................................................... 29

Table 3.2.1(e). Maximum Horizontal Load for Lag Screws in Wood-Load Perpendicular to Grain, lb. ...... 30Table 3.2.1(f). Maximum Horizontal Load for Through Bolts in Steel (bolt perpendicular to mounting

surface), lb. ........................................................................................................................... 30Table 3.2.1(g). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular to

Grain, N (Metric) .................................................................................................................. 31Table 3.2.1(g). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular to

Grain, N (Metric) (continued) ............................................................................................... 32Table 3.2.1(h). Maximum Horizontal Load for Lag Screws in Wood-Load Perpendicular to

Grain, N (Metric) .................................................................................................................. 33Table 3.2.1(i). Maximum Horizontal Load for Through Bolts in Steel (bolt perpendicular to

mounting surface), N ............................................................................................................. 33Table 3.9.2. Horizontal Seismic Design Loads for System No. 1 ................................................................ 49Table 3.9.3. Horizontal Seismic Design Load Calculations for System No. 2 ............................................. 55Table 3.9.4. Horizontal Seismic Design Loads for System No. 3 ................................................................ 59

Earthquake Protection 2-8Factory Mutual Property Loss Prevention Data Sheets Page 3


1.0 SCOPE

1.1 General

This data sheet provides recommendations for earthquake protection for fixed water-based fire protection sys-tems. Recommendations contained herein should be applied to locations located in earthquake zones 150or less, as shown in the Appendix of Factory Mutual Data Sheet 1-2, Maps of Earthquake Zones.

This edition revises the previous edition of this data sheet to provide enhancements to useability of guide-lines for earthquake protection of sprinkler systems and other types of water-based protection systems andtheir components. The guidelines contained herein supersede any guidelines which may appear in otherFactory Mutual Data Sheets, particularly those which may be adaptations of related NFPA standards andwhich may contain differing earthquake protection guidelines.

1.2 Major Changes

1. In certain cases, single diagonal sway bracing is now allowed without the need to address the net verti-cal uplift force component resulting from the horizontal seismic load. When the single brace angle from thevertical is such that one-half the weight of the piping within the zone of influence for that brace equals orexceeds the net vertical uplift force component, a single diagonal sway brace will suffice. For a ‘‘G’’ factorof 0.5, sway brace angles of 45 degrees or more from the vertical will qualify for this approach. For higher ‘‘G’’factors, correspondingly higher sway brace angles from the vertical will be needed.

2. Tension-only sway bracing using brace members with an l/r = 300 or less is now allowed. In those casestwo opposing diagonal braces are needed, and additionally, a vertical brace is needed when required to resistany net vertical uplift force component resulting from the horizontal seismic load.

3. Revised guidelines are provide for sway bracing for branch lines 21⁄2 in. (64 mm) and larger. Previously,sway bracing was only recommended for these branch lines on gridded sprinkler systems. Now, sway brac-ing is needed for 21⁄2 in. (64 mm) and larger branch lines on all types of systems. These revised guidelineswill apply to any branch lines or portion of branch lines that exceed 20 ft (6.1 m) in length for lateral sway brac-ing, and 25 ft (7.6 m) in length for longitudinal sway bracing.

4. A reference to ‘‘C’’ and ‘‘Z’’ purlins has been added in Section 3.2.1.2, Step 4 to clarify that these struc-tural members also need to be evaluated for adequacy as attachment points for sway bracing.

5. Additional guidance has been provided in Sections 3.2.2.2 and 3.2.2.3 to clarify the use of flexiblecouplings in multistory buildings or where piping passes through walls in relation to whether proper clear-ances are provided.

6. Section 3.2.2.7 has been revised to clarify that piping passing between two buildings which are notattached also needs a seismic separation assembly.

7. Section 3.2.4.1 has been revised to delete the recommendation for anchorage of riser stubs to under-ground elbows.

8. Section 3.2.6.1, item 4, has been revise to disallow the use of c-clamp hangers on purlins with upwardlips.

9. Section 3.2.7 is added recommend against the use of nonmetallic pipe in aboveground installations.

2.0 GENERAL

2.1 Discussion

Earthquake related strains are imparted to a fire protection system through the building or the ground towhich it is attached or through the inertial movement within the system itself. Uncontrolled differential move-ment can cause damage when fire protection systems are not provided in a systematic manner with the nec-essary features that incorporate sway bracing, flexibility, clearances and anchorage where needed. Themost common type of damage, based on past experience, is water damage due to water leakage frombroken overhead sprinkler piping or sprinklers, primarily due to lack of sway bracing where needed.



Common sources of water damage were broken or separated overhead sprinkler piping, broken sprinklersdue to impact with nearby structural members or other equipment, broken sprinklers or pipe drops due toexcessive differential movement between unbraced suspended ceilings and the pipe drops, and brokenin-rack sprinkler system piping or sprinklers due to excessive rack movement. In addition to damage fromwater leakage, fire protection systems are often impaired due to direct damage to the systems, or due to dam-age to public water supplies or utilities needed for fire protection. Significant impairments to fire protectionsystems may expose a facility to a severe fire loss following an earthquake.

In evaluating the many incidents of damage, two conclusions are very apparent:

1. Only by providing in a systematic manner the necessary features which incorporate sway brac-ing, flexibility, clearances and anchorage where needed can a fire protection system be adequatelyprotected to mitigate potential damage from earthquakes.

2. Omission of only a few of the critical components necessary for adequate earthquake protectionmay create conditions where significant earthquake damage may result in substantial water damage.The necessary shutdown of the system to stop further damage also creates a fire protection sys-tem impairment.

Specific discussion regarding earthquake protection and recommendations for each type of protection systemfollow in Section 3.0 Recommendations.

3.0 RECOMMENDATIONS

3.1 General

Recommendations made herein are intended to: 1) greatly improve the likelihood that the fire protection sys-tems will remain in working condition after the earthquake, and 2) minimize potential water damage fromfire protection system leakage. For each type of fire protection system described in the following sec-tions, all recommendations should be completed to ensure that the system will perform as intendedduring an earthquake. In general, recommendations fall into the following seven categories:

1. brace piping or equipment to minimize uncontrolled differential movement between piping or equipmentand the structure to which it is attached,

2. provide flexibility on piping systems and on other equipment where differential movement between portionsof those piping systems or equipment is expected,

3. provide clearance between piping or equipment and structural members, walls, floors, or other objectsso that potential damage from impact is minimized,

4. provide anchorage to minimize potential sliding and/or overturning,

5. use appropriate types of pipe hangers and sway bracing, properly locate them, and properly attach themto the structure to minimize the potential for pullout,

6. use appropriate types of piping and pipe joining methods to minimize potential pipe breaks, and

7. provide fire protection system plans and calculations with proper verification of design, and proper verifi-cation that the completed installation is in accordance with the design as well as good installation practices.

3.2 Sprinkler Systems, Including In-rack Sprinkler Systems and Small-Hose Piping Systems

3.2.1 Sway Bracing

3.2.1.1 General

Sway bracing for sprinkler systems, when provided in conjunction with the flexibility recommended in Sec-tion 3.2.2, will minimize differential movement between the piping system and the structure to which it isattached. Flexible couplings allow sufficient flexibility between portions of systems where needed.



Actual design of sway bracing is based on horizontal seismic load. Acceptable sway bracing type, orien-tation and attachment methods (to both the sprinkler pipe and the structure) need to simulta-neously provide adequate resistance to both the horizontal seismic load and the net vertical upliftforce component resulting from the horizontal seismic load less any effective offset to that verticalforce component due to sprinkler piping dead weight.

For risers and overhead sprinkler piping, there are two sway bracing designs: two-way and four-way. Two-way braces are either longitudinal or lateral, depending on their orientation with the axis of the horizontal pipe.(See Figs.3.2.1[a] through [d]). Lateral and longitudinal braces resist differential movement perpendicularand parallel, respectively, to the axis of the pipe, and are typically used on feedmains, on crossmains andon system branch lines that are 21⁄2 in. (63 mm) and larger in diameter.

Four-way sway bracing resists differential movement in all horizontal directions, and is typically provided onrisers. Where lateral and longitudinal sway bracing locations coincide, four-way bracing may be used tosatisfy design requirements for both.

3.2.1.2 Sway Brace Design

There are four steps to properly design sway bracing:

Step 1: Lay out sway bracing locations with respect to the sprinkler piping and to the structural membersto which the bracing will be attached.

Step 2: Calculate the seismic design load requirements for each sway bracing location.

Step 3: Select the proper sway bracing shape, angle of attachment, size and maximum length based onthe horizontal design load requirement.

Step 4: Select the proper attachment method for the sway bracing to the structure and to the piping.

Specific guidelines follow.

Fig. 3.2.1(a). Lateral sway bracing using one vertical and one diagonal brace.



Step 1. Lay out of Sway Bracing Locations . Lay out sway bracing locations as follows:

1. Risers: A four-way sway brace should be provided on all sprinkler risers (whether single or manifoldedtype) within 24 in. (0.6 m) of the top of the riser as shown in Figures 3.2.2.2 (a, b, and c). For risers locatedon the outside of the building, either Detail A or B of Figure 3.2.2.2(a) may be used, with the brace attachedto a structural element. The use of manifolded sway bracing at the top of multiple adjacent risers requirescareful design work and should be avoided. If used, no more than two risers should be used in a mani-folded arrangement, and bracing should be designed to carry the total loads for both risers.

Intermediate four-way sway bracing should be provided at an interval not to exceed 40 ft (12.2 m). Where flex-ible couplings are used, four-way sway bracing should be provided within 2 ft (0.6 m) of every other flex-ible coupling (with no more than two flexible couplings between sway brace locations). In multistory buildings,a four-way brace is considered to exist when the riser passes through a structural floor and clearances donot exceed the minimums per Section 3.2.3.1 by more than 1 inch.

A two-way lateral sway brace should be provided within 2 ft (0.6 m) of the end of any horizontal manifoldpiping longer than 6 ft (1.8 m) or when there is one or more flexible coupling(s) on either the horizontal mani-fold piping or on the riser stub between the floor and the connection to the horizontal manifold piping. SeeFig. 3.2.2.2(b).

2. Vertical crossmain or feedmain piping: Four-way sway bracing should be provided at both the top and bot-tom of the vertical pipe run of 6 ft (1.8 m) or more. Each brace should be located within 24 in. (0.6 m) ofthe respective piping turn. (In addition, flexible couplings should be provided in conjunction with Section3.2.2.3.) Intermediate four-way sway bracing should be provided similar to risers as recommended in item 1above.

Fig. 3.2.1(b). Lateral sway bracing using two opposing diagonal braces.



Fig. 3.2.1(c). Longitudinal sway bracing using one vertical and one diagonal brace.

Fig. 3.2.1(d). Longitudinal sway bracing using two diagonal braces.



For vertical pipe runs of less than 6 ft (1.8 m) without bracing provided, flexible couplings should not be presentwithin the vertical pipe run (including the piping turns). If flexible couplings are provided at one or both turnsfor vertical pipe runs of less than 6 ft (1.8 m), then four-way bracing should be provided within 24 in. (0.6 m)of each turn equipped with flexible coupling(s).

3. Horizontal changes of direction: Crossmain or feedmain piping which have pipe runs of 6 ft (1.8 m) ormore adjacent to the change in direction should be provided with both lateral and longitudinal sway brac-ing at the change of direction. Straight pipe runs after the last change in direction should be provided with swaybracing per items 4, 5 and 6 below. Note that when the pipe connection at the change in direction is madeusing a flexible coupling, then additional sway bracing per item 5, below, will be necessary, regardless ofthe length of the pipe run adjacent to the change in direction.

4. Ends of feedmains and crossmains: Provide lateral bracing within 6 ft (1.8 m) of the end, and providelongitudinal bracing within 40 ft (12.2 m) of the end. When structural member locations for lateral sway brac-ing attachment are such that this 6 ft (1.8 m) distance cannot be met, the crossmain or feedmain shouldbe extended to allow proper location of the lateral sway bracing. (Note that for gridded system crossmainswhich terminate close to a wall it may be necessary to provide and elbow and cap, rather than just a cap, onthe ends of the crossmains to facilitate flushing.) Seismic separation assemblies in feedmains and cross-mains per Section 3.2.2.7 shall be considered as the end of the piping on both sides of the assembly.

5. Unnecessary flexible couplings: When more flexible couplings than recommended in Section 3.2.2.2 areinstalled on feedmains, on crossmains or on branch lines or portions of branch lines that are 21⁄2 in. (64 mm)and larger and greater than 20 ft (6.1 m) in length, install additional lateral sway bracing as follows:

a. within 2 ft (0.6 m) of every other flexible coupling on straight pipe runs, with no more than two flex-ible couplings (one of which is located within 2 ft (0.6 m) of sway bracing) between sway bracing locations,and

b. within 2 ft (0.6 m) of every flexible coupling installed at changes in horizontal pipe direction.

6. Straight pipe runs: After giving credit to any sway bracing installed per items 1 through 5 above, sway brac-ing should be provided at a maximum spacing of 40 ft (12.2 m) for lateral sway bracing and 80 ft (24.4 m)for longitudinal sway bracing per the following guidelines:

a. Provide lateral sway bracing on all feedmains, on all crossmains, and on all branch lines and por-tions of branch lines that are 21⁄2 in (64 mm) and larger and greater than 20 ft (6.1 m) in length. Space brac-ing at a maximum of 40 ft (12.2 m), recognizing that for feedmains and crossmains, there should be lateralbracing within 6 ft. (1.8 m) of the end of the main(s), per item 4 above.

A four-way brace at the top of the riser may be counted as the initial lateral brace for the attached feed-main or crossmain at the connection to the riser.

For branch lines 21⁄2 in. (64 mm) or larger that need sway bracing, the first lateral sway bracing locationshould be no closer than 20 ft (6.1 m) nor greater than 40 ft (12.2 m) from the branch line connectionto the crossmain. Branch lines or portions of branch lines 21⁄2 in. (64 mm) or larger and less than 20 ft(6.1 m) in length do not require lateral sway bracing. However, the loads from these branch lines need tobe distributed to the longitudinal sway bracing on the crossmain per Step 2 below.

U-hangers, including wraparound types, should not be used as lateral sway bracing for feedmains andcrossmains. Wraparound U-hangers may be used as lateral sway bracing for branch lines which requiresway bracing if they meet the following criteria:

— have both legs bent out at least 30 degrees from the vertical,

— are the proper diameter and length per Table 3.2.1(b) for the seismic loads involved,

— are properly attached to the building structure per Step 4 , and

— there is no more than 1⁄2 in. (13 mm) of space between the top of the branch line piping andwraparound portion of the U-hanger.

For branch lines less than 4 inches (102 mm) in diameter, lateral sway bracing is not needed on pipesindividually supported by rods which meet the following criteria:



— all rods have a length less than 6 in. (152 mm) from the supporting member attachment to the topof the branch line;

— there is no more than 1⁄2 in. (13 mm) of space between the top of the branch line piping and thebottom of the support rod.

This does not apply to feedmains and crossmains.

b. Provide longitudinal sway bracing on all feedmains, on all crossmains, and on all branch lines andportions of branch lines that are 21⁄2 in. (64 mm) and larger and greater than 25 ft (7.6 m) in length. Spacebracing at a maximum of 80 ft (24.4 m), recognizing that for feedmains and crossmain, there should belongitudinal bracing within 40 ft (12.2 m) of the end of the main(s), per item 4, above.

A four-way brace at the top of the riser may be counted as the initial longitudinal brace for the attached feed-main or crossmain at the connection to the riser.

Note that if a lateral brace is within 2 ft (0.6 m) of the end of a feedmain or crossmain piping connectionto another main which is perpendicular and of the same or lesser pipe size, then the lateral brace maybe used to also act as a longitudinal brace for the other main, and the design load for the sway brace willneed to include both the lateral and longitudinal loads per Step 2 below.

For branch lines 21⁄2 in. (64 mm) and larger that need sway bracing, the first longitudinal sway bracing loca-tion closest to the crossmain should be located between 25 ft and 50 ft (7.6 m and 15.2 m) from the branchline connection to the crossmain. Dead-end branch lines less than 25 ft (7.6 m) in length do not requirelongitudinal sway bracing. The longitudinal sway bracing of branch lines should not be considered asproviding lateral sway bracing of the crossmain.

Sway bracing layout locations will usually need to coincide with the structural members to which the swaybraces will be attached.

Step 2. Calculate Seismic Design Load Requirements for Each Sway Bracing Location. Design loadrequirements (H) for each sway bracing location are calculated by multiplying the weight of the water-filledpiping located within the zone of influence (Wp) for that sway bracing location times the horizontal accel-eration (‘‘G’’ factor) expected from an earthquake. (The zone of influence for a sway bracing location includesall piping to be included in the load distribution calculation for that bracing location, based on the symmetri-cal layout of all the various bracing locations.) Table 3.2.1(a) shows weights for water-filled pipe, to be usedwith the appropriate ‘‘G’’ factor to calculate design loads. It is usually helpful to prepare a brace location sched-ule with the calculated loads to help with Steps 3 and 4.

For earthquake zones 150 and less, use a minimum ‘‘G’’ factor of 0.5, or a higher ‘‘G’’ factor if requiredby local authorities per the building code for the location involved.

The design load for each sway bracing location is calculated by multiplying the cumulative total weight ofthe piping within the zone of influence for that bracing location times the horizontal acceleration ‘‘G’’ factor.(For example, 80 ft (24.4 m) of Schedule 10 6 in. (152 mm) pipe has a total weight of 80 ft (24.2 m) x 23.0lb/ft (338 N/m) = 1840 lb (8180 N). For a ‘‘G’’ factor of 0.5, 1840 lb (8180 N) x 0.5 = 920 lb (4090 N), whichis the horizontal design load requirement for that sway bracing location.)

Calculate design loads as follows:

1. Four-way sway bracing at risers:

Calculate design loads to include the full length of the riser and the length of feedmain piping within the zoneof influence of the four-way riser brace. The four-way riser brace must be designed to handle both lateraland longitudinal design loads. Manifolded bracing design must include the total load for the two being braced.

2. Lateral two-way sway bracing:

a. for feedmains, calculate design loads to include the length of the feedmain being braced

b. for crossmains, calculate design loads to include the length of crossmain being braced plus allbranchline loads not distributed to branchline longitudinal sway bracing.



c. for branch lines and portions of branch lines that are 21⁄2 in (64 mm) or larger and greater than 25 ft(7.6 m) in length, the load distribution for the first lateral sway bracing location nearest the crossmainconnection, may either be equally distributed to the crossmain longitudinal bracing and the first lateralsway bracing location (see item 3.b., below), or may be totally distributed to the first lateral sway brac-ing location. Calculate the design loads for additional lateral sway bracing to include the length of branchline being braced.

d. for lateral sway braces which are located within 2 ft (0.6 m) of the end of a feedmain or crossmain con-nection to another perpendicular main of the same or smaller diameter, and which will also be used asa longitudinal sway brace for that main, calculate the design load to include the total lateral and longitu-dinal loads.

3. Longitudinal two-way sway bracing:

a. for feedmains, calculate design loads to include the length of feedmain being braced.

b. for crossmains, calculate design loads to include the length of crossmain being braced; do not includeloads from branchlines, except when a portion of branchline lateral sway bracing is being included asdescribed in item 2.c., above.

c. for gridded system branchlines that are 21⁄2 in. (64 mm) or larger, calculate design loads to includethe length of branchline being braced. The load for the piping between the crossmain and the first brac-ing location may be equally distributed between that bracing location and the crossmain lateral sway brac-ing as described in item 2.b., above.

Note that in certain cases four-way braces may be used on crossmains or at feedmain/crossmain inter-sections to satisfy both longitudinal and lateral bracing requirements. In those cases the longitudinal portionwill include only the feedmain or crossmain loads, while the lateral portion will consider both the cross-main and branch line loads (unless branchlines are provided with sway bracing).

Table 3.2.1(a). Weight of Water-filled Pipe

Schedule40 Pipe, in. (mm)

Weight,lb/ft (N/m)

1 (25) 2.1 (31)11⁄4 (32) 2.9 (43)11⁄2 (38) 3.6 (53)2 (51) 5.1 (75)

21⁄2 (64) 7.9 (116)3 (76) 10.8 (159)

3½ (89) 13.5 (198)4 (102) 16.4 (241)5 (127) 23.5 (345)6 (152) 31.7 (465)8* (203) 47.7 (700)

Schedule 10 and Lightwall1 (25) 1.8 (26)

11⁄4 (32) 2.5 (37)1½ (38) 3.0 (44)2 (51) 4.2 (62)

2½ (64) 5.9 (87)3 (76) 7.9 (116)

3½ (89) 9.8 (144)4 (102) 11.8 (173)5 (127) 17.3 (254)6 (152) 23.0 (338)8 (203) 40.1 (589)

* Schedule 30



Step 3. Select the Proper Sway Bracing Shape, Size and Maximum Length. Sway bracing consists ofeither sufficient diagonal element(s) (at an angle of at least 30 degrees from the vertical), or diagonal plus ver-tical elements to resist both horizontal seismic loads and the net vertical force components. Figures 3.2.1(a)and (b) show bracing options for lateral sway bracing. Figures 3.2.1(c) and (d) show bracing options forlongitudinal sway bracing.

For braces used to resist both tension and compression, the shape, size and length of the braces shouldensure that the slenderness ratio, l/r (length/least radius of gyration), does not exceed 200, in order to pro-vide adequate resistance to buckling. For braces used in tension only, the shape, size and length of thebraces should ensure that the slenderness ratio, l/r, does not exceed 300. Braces can be steel pipe, steelangle, steel rods, or steel flats.

U-hangers, including wraparound types, should not be used as lateral sway bracing for feedmains and cross-mains. Wraparound u-hangers may be used as lateral sway bracing for branch lines that require sway brac-ing if they meet the following criteria:

a. have both legs bent out at least 30 degrees from the vertical,

b. are the proper diameter and length per Table 3.2.1(b) for the seismic loads involved,

c. are properly attached to the building structure per Step 4, and

d. there is no more than 1⁄2 in. (13 mm) of space between the top of the branch line piping and wraparoundportion of the u-hanger.

Table 3.2.1(b) indicates maximum allowable lengths for different brace shapes and sizes. The table alsoshows maximum horizontal design load, H, for each brace (as determined in Step 2 ) for three different rangesof angles for the brace as measured from the vertical. Maximum horizontal design loads are included forl/r=200, l/r=100, and for l/r = 300 (tension only). Selection of each brace should be such that the maximumlength from the table is not exceeded, based on the actual length of the brace between attachment pointsto the structure and the pipe being braced. The following guidelines apply:

1. For Fig 3.2.1(a) or (c) using one vertical and one diagonal brace:

• Angle from the vertical for Brace A must be at least 30 degrees.

• Brace A should be sized and arranged to carry in both tension and compression the full horizontal designload H, determined in Step 2 .

• Brace B, when needed, can either be of the same shape and size as Brace A, and connected to thepipe at the same point as Brace A, without any further calculation, or can be selected on the basis of theactual calculated net vertical uplift force. The net vertical uplift force derived from the horizontal designload H, is:

VF = (H/tan α) – 1⁄2 WP

Where VF = Net vertical uplift force

H = Horizontal design load from Step 2

α = Angle of Brace A from vertical

WP = Weight of the water filled pipe within the zone of influence

If VF is less than or equal to 0 (zero), Brace B is not required.

Brace B, when needed, may be a hanger which is located no more than 6 in. (152 mm) from the pointof attachment on the pipe for Brace A and which meets the following criteria:

i. the hanger has been determined to be able to resist the net vertical resultant load uplift forceVF (this may necessitate the use of a rod stiffener or other means, but in any case the l/r shouldnot exceed 200.),

ii. the hanger is fastened to the structure by a positive means of mechanical attachment, such asthrough bolts, lag screws or concrete anchors which are properly sized for the load, and



iii. the hanger attachment to the fire protection system piping is snug and concentric, with no morethan 1⁄2 in. (13 mm) between the top of the piping and the hanger so that excessive movementcannot occur.

2. For Fig. 3.2.1(b) or (d) using two opposing diagonal braces each capable of resisting tension and com-pression (l/r = 200 or less):

• Angle from vertical for Braces A1 and A2 must be at least 30 degrees.

• Both Braces A1 and A2for Fig.3.2.1(b) or (d) should be sized and arranged to carry one-half the horizontaldesign load H determined in Step 2 . Alternatively, design load H may be proportionately distributed tothe two braces. Considering Fig. 3.2.1(b), if the distributed portion of the horizontal seismic load reactedby Brace A1 is H1 and the distributed load reacted by Brace A2 is H2, the load distribution can be expressedas:

H1 = (H)((tan θ1)/(tan θ1 + tan θ2))

H2 = (H)((tan θ2)/(tan θ1 + tan θ2))

The distribution of loads will be similar for the arrangement shown in Fig. 3.2.1(d).

• These sway bracing arrangements will provide adequate resistance to vertical force and no additionalprocedures are needed in that regard.

3. For tension only sway bracing (l/r = 300 or less), treat as a special condition of Figs. 3.2.1(a) or (c) byproviding opposing diagonal braces (i.e., two Braces ‘‘A’’) similar to item 1 above:

• Angle from vertical for Braces A must be at least 30 degrees.

• Both Braces A for Figs. 3.2.1(a) or (c) should be sized and arranged to carry, in tension, the full hori-zontal design load H determined in Step 2 . This is necessary because neither brace is being consid-ered as capable of resisting compression. The use of this arrangement can be helpful when it is necessaryto have longer brace members due to structural or other physical or dimensional constraints.

• Brace ‘‘B,’’ when needed, may vary in shape and size from Braces ‘‘A’’ and should be evaluated basedon the net vertical uplift force (VF) per item 1 above.

4. For the case where the piping is supported firmly against the underside of a structural member:

• Such attachment may qualify as a lateral sway brace if the attachment method and fasteners are capableof resisting the horizontal seismic load (consideration of vertical resultant force is unnecessary). Allother sway bracing locations per Step 1 will still be necessary.

NOTES for Table 3.2.1(b)

NOTE 1: Following are tangent values for various angles:Angle Tangent Angle Tangent

30 0.58 60 1.73

35 0.70 65 2.14

40 0.84 70 2.74

45 1.00 75 3.73

50 1.19 80 5.67

55 1.43 85 11.43

NOTE 2: The slenderness ratio, l/r, is defined as brace length/least radius of gyration. The least radius of gyration, r, can be determinedfor various brace shapes as follows:

Pipe: r = (√r + r )/22o

2I

where ro = radius of outside pipe wallrI = radius of inside pipeRods: r = (radius of rod/2)Flats: r = 0.29hwhere h = smaller dimension of two sides(Angles require a much more detailed calculation.)



Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members

ShapeSize, in.

Least Radiusof Gyration

Maximum Length,ft, in.

Maximum Horizontal Load, lbAngle of Brace from Vertical

30°-44° 45°-59° 60°-90°l/r = 200

Pipe (Sched 40)1 0.42 7 ft 0 in. 1767 2500 306111⁄4 0.54 9 ft 0 in. 2393 3385 41451½ 0.623 10 ft 4 in. 2858 4043 49552 0.787 13 ft 1 in. 3828 5414 6630Pipe (Sched. 10)1 0.43 7 ft 2 in. 1477 2090 255911⁄4 0.55 9 ft 2 in. 1900 2687 32911½ 0.634 10 ft 7 in. 2194 3103 38002 0.802 13 ft 4 in. 2771 3926 4803Angles11⁄22x11⁄2x1⁄4 0.292 4 ft 10 in. 2461 3481 42632x2x1⁄4 0.391 6 ft 6 in. 3356 4746 581321⁄2x2x1⁄4 0.424 7 ft 0 in. 3792 5363 656921⁄2x21⁄2x1⁄4 0.491 8 ft 2 in. 4257 6021 73743x21⁄2x1⁄4 0.528 8 ft 10 in. 4687 6628 81183x3x1⁄4 0.592 9 ft 10 in. 5152 7286 8923Rods3⁄8 .094 1 ft 6 in. 395 559 685½ .125 2 ft 6 in. 702 993 12175⁄8 .156 2 ft 7 in. 1087 1537 18833⁄4 .188 3 ft 1 in. 1580 2235 27377⁄8 .219 3 ft 7 in. 2151 3043 3726Flats11⁄2x1⁄4 .0725 1 ft 2 in. 1118 1581 19362x1⁄4 .0725 1 ft 2 in. 1789 2530 30982x3⁄8 .109 1 ft 9 in. 2683 3795 4648



Table 3.2.1(b). Maximum Horizontal Loads for Various Sway Brace Members (Metric)

ShapeSize, mm


Maximum Length,m

Maximum horizontal Load, NAngle of Brace from Vertical

30°-44° 45°-59° 60°-90°l/r = 200

Pie (Sched 40)25 0.42 2.1 7860 11120 1361532 0.54 2.7 10645 15057 1843838 0.623 3.2 12713 17984 2204051 0.787 4.0 17028 24082 29492Pipe (Sched 10)25 0.43 2.2 6570 9297 1138332 0.55 2.8 8452 11952 1463938 0.634 3.2 9759 13803 1690351 0.802 4.1 12326 17464 21365Angles38x38x6 0.292 1.5 10947 15484 1896351x51x6 0.391 2.0 14928 21111 2585764x51x6 0.424 2.1 16868 23856 2922064x64x6 0.491 2.5 18936 26783 3280176x64x6 0.528 2.7 20848 29483 3611076x76x6 0.592 3.0 22917 32410 39691Rods10 .094 0.5 1757 2486 304713 .125 0.8 3123 4417 541316 .156 0.8 4835 6837 837619 .188 0.9 7028 9942 1217522 .219 1.1 9568 13536 16574Flats38x6 .0725 0.4 4973 7033 861251x6 .0725 0.4 7958 11254 1378051x10 .109 0.5 11935 16881 20675


ShapeSize, in.




30°-44° 45°-59° 60°-90°l/r = 100

Pipe (Sched 40)1 0.42 3 ft 6 in. 7068 9996 1224211⁄4 0.54 4 ft 6 in. 9567 13530 165701½ 0.623 5 ft 2 in. 11441 16181 198172 0.787 6 ft 6 in. 15377 21746 26634Pipe (Sched. 10)1 0.43 3 ft 7 in. 5910 8359 1023711⁄4 0.55 4 ft 7 in. 7600 10749 131641½ 0.634 5 ft 3 in. 8777 12412 152022 0.802 6 ft 8 in. 11105 15705 19235Rods3⁄8 .094 0 ft 9 in. 1580 2234 2737½ .125 1 ft 0 in. 2809 3972 48655⁄8 .156 1 ft 3 in. 4390 6209 76053⁄4 .188 1 ft 6 in. 6322 8941 109517⁄8 .219 1 ft 9 in. 8675 12169 14904




ShapeSize, mm


Maximum Length,m

Maximum Horizontal Load, NAngle of Brace from Vertical

30°-44° 45°-59° 60°-90°l/r = 100

Pipe (Sched 40)25 0.42 1.1 31440 44164 5444532 0.54 1.4 42556 60185 7370738 0.623 1.6 50892 71976 8815051 0.787 2.0 68400 96731 118473Pipe (Sched 10)25 0.43 1.2 26289 37183 4553632 0.55 1.4 33806 47814 5855638 0.634 1.6 39042 55211 6762251 0.802 2.0 49397 69859 85561Rods10 .094 0.2 7028 9937 1217513 .125 0.3 12495 17668 2164016 .156 0.4 19528 27619 3382919 .188 0.45 28122 39771 4871222 .219 0.55 38588 54130 66296


ShapeSize, in.




30°-44° 45°-59° 60°-90°l/r = 300

Pipe (Sched 40)1 0.42 10 ft 6 in. 786 1111 136011⁄4 0.54 13 ft 6 in. 1063 1503 184111⁄2 0.623 15 ft 7 in. 1272 1798 22022 0.787 19 ft 8 in. 1666 2355 2885Rods3⁄8 .094 2 ft 4 in. 176 248 3041⁄2 .125 3 ft 1 in. 312 441 5405⁄8 .156 3 ft 11 in. 488 690 8453⁄4 .188 4 ft 8 in. 702 993 12177⁄8 .219 5 ft 6 in. 956 1352 1656




ShapeSize, mm


Maximum Length,m

Maximum Horizontal Load, NAngle of Brace from Vertical

30°-44° 45°-59° 60°-90°l/r = 300

Pipe (Sched 40)25 0.42 3.2 3496 4942 604932 0.54 4.1 4728 6685 818938 0.623 4.8 5658 7998 979551 0.787 6.0 7410 10475 12832Rods10 .094 0.7 783 1103 135213 .125 0.9 1388 1962 240216 .156 1.2 2171 3069 375919 .188 1.4 3123 4417 541322 .219 1.7 4252 6014 7366



Step 4. Select the Proper Attachment Method for the Sway Bracing to the Structure and to the Piping .Proper attachment of sway bracing to the structure and to the piping is a critical performance point for thesway bracing system. All parts and fittings should lie in a straight line to avoid eccentric loading on any of thesway bracing components. All means of connection to the structure or the piping should be of type havingpositive mechanical attachment which can be visually verified as to correct installation.

1. Attachment to the Structure. The two primary recommendations to assure proper attachment to the struc-ture are: 1) verify that the structural member to which the sway bracing is attached and the actual locationof the attachment to that member has been determined by qualified personnel to be capable of withstand-ing the anticipated seismic load, and 2) verify that the fasteners used are capable of withstanding the antici-pated seismic load and are properly installed.

a. Structural members. Verification that the structural member and the attachment point for the sway brac-ing is adequate to carry the anticipated load should be provided with the system design information. When-ever any doubt exists regarding the load carrying capabilities, a structural engineering analysis shouldbe provided with the design information to verify adequacy.

b. Fasteners. The type of fastener used will depend on whether the sway bracing will be attached towood, steel or concrete structural members, and to a certain extent on what type of brace is being used.(Guidelines for attachment to wood, steel or concrete structural members follow.) Regardless of the typeof structural member used as an attachment point, there are three possible fastener attachment configu-rations, all of which create different shear and tension loadings on the fastener. These configurations are:Configuration A—Fastener attached into underside of structural member; Configuration B—Fastenerattached into side of structural member with axis of fastener parallel to axis of brace; ConfigurationC—Fastener attached into face of structural member with axis of fastener perpendicular to axis of brace.

These three fastener configurations, coupled with the two possible sway bracing configurations (twoopposing diagonal braces or one diagonal and one vertical brace) create six possible combinations of fas-tener and sway bracing configurations. The six configurations are illustrated in Figures 3.2.1.2(a) through(f). The figures also include the derivation of shear and tension loading, which are dependent on the cal-culated horizontal seismic load H determined from Step 2 , the brace angle from the vertical, and the fas-tener configuration. (The figures show sway bracing attached to the piping as lateral sway bracing, butlongitudinal sway bracing and attachments will be similarly evaluated.)

For sway bracing configurations using two opposing tension and compression diagonal braces (Step 3,item 2), one-half the horizontal seismic load (H/2) should be distributed to each fastener, regardless of theindividual load carrying capacity of each of the opposing diagonal braces. For example, in Fig. 3.2.1.2(a),if Brace A1 and its fastener can carry 60 percent of load H, Brace A2 fastener should be designed fora minimum of 50 percent of load H, not 40 percent. While proportional distribution of loading is an accept-able alternative for the sway brace member itself, such a method for fasteners is undesirable becauseof the indeterminacy of the load at any given time and the criticality of successful fastener performanceto successful system performance.

For sway bracing configurations using two opposing tension only diagonal braces (Step 3, item 3), thefull horizontal seismic load (H) should be distributed to each fastener because neither brace is being con-sidered as capable of resisting compression. Fastener forces for two opposing diagonal tension onlybraces should be determined based on Figures 3.2.1.2(b), (d), and (f) for each brace since each diagonalbrace is assumed to resist the full horizontal seismic load (H) in tension.

Note that Figures 3.2.1.2(a) through (f) show the same fastener configuration for the two braces in each fig-ure. This will not always be the case. When the two braces have different fastener configurations, loadcapacities for each fastener should be determined for the appropriate configuration.

NOTE: In Figs. 3.2.1.2(a) through (f), seismic load H is shown occurring in a direction to the left of the page, for the purpose of illustrat-ing the derivation of shear and tension loading as a result of load H in that direction. In an actual earthquake, the motion could be in any direc-tion. Shear and tension load derivations will not change, but will change direction with a change in direction of seismic load H. This illustratesa key concept relating to sway bracing system performance. No matter what direction the earthquake motion is, the combination of lat-eral and longitudinal sway bracing properly located and designed to withstand both horizontal and resultant vertical motion, and which is prop-erly attached to the structure and piping to withstand both shear and tension loading on the structure and fasteners, will assure that thesway bracing system has the best chance to minimize potential damage to the system. For example, if the lateral sway bracing is alignedin the north-south axis, and the longitudinal sway bracing is aligned in the east-west axis, an earthquake which creates movement in thenorthwest-southeast axis will require proper interaction of the entire sway bracing system to minimize damage potentials. Neither the lateralnor longitudinal sway bracing by itself would be expected to handle non-axial seismic loading.



Fig. 3.2.1.2(a). Configuration A Fastener with two opposing diagonal braces−fastenersinto underside of structural member.

Fig. 3.2.1.2(b). Configuration A fasteners with one diagonal and one vertical brace-fastenersinto underside of structural member.



Fig. 3.2.1.2(c). Configuration B Fastener with two opposing diagonal braces−fasteners into side of structural member.

Fig. 3.2.1.2(d). Configuration B fasteners with one diagonal and one vertical brace−fastenersinto side of structural member.



Fig. 3.2.1.2(e). Configuration C Fastener with two opposing diagonal braces−fasteners into face of structural member.



Fig. 3.2.1.2(f). Configuration C fasteners with one diagonal and one vertical brace−fastenersinto face of structural member.



For different brace shapes, attachment methods may vary. Steel pipe can either have a flattened end withholes to accommodate the fastener, or if threaded can be used with a special fitting as shown in Fig. 3.2.1.2(g).Steel angle and wraparound u-hooks for use as lateral sway bracing on branchlines will generally have holesto accommodate the fastener. Rods and flats are not common for use due to length restriction, but if usedshould have an appropriate means to allow proper fastening to the structure.

Attachment to Wood Structural Members. Sway braces should be connected to wood components withthrough bolts whenever practicable (see Fig. 3.2.1.2[h]). Through bolts, a positive means of attachment, takeadvantage of the full strength of the wood member. They can be visually verified in the field as to correctinstallation. Also, quality control problems often associated with lag screws are eliminated. When roof con-figuration or other factors make the use of through bolts impractical, lag screws may be used. Careful atten-tion to correct installation practices will ensure proper performance.

In any case, verification of the capability of the structural member and the point of attachment to withstandthe anticipated load should be included with the system design information. It may be necessary in somecases, such as when wood members are dimensionally inadequate, to carry the anticipated loads, to rein-force the structural members (in this case a structural engineering analysis or verification should be includedwith system design information) to ensure that the members provide adequate load carrying capability.

Tables 3.2.1(d) and 3.2.1(e); (Tables 3.2.1(g) and 3.2.1(h) for metric) provide maximum horizontal designloads for through bolts and lag screws in wood, based on the configuration of the fastener (as defined above)with respect to the structural member, and the angle of the brace from the vertical. The load values given cor-respond to the applied horizontal seismic load (either H or H/2, depending on sway bracing configuration)for the worst-case angle from the vertical for the range of angles given. In other words, seismic design loadH or H/2 should not exceed the table values for the fastener size and configuration selected. Load valuesfor lag screws are based on minimum wood penetration of eight diameters.

Note: All values in Tables 3.2.1(d) and 3.2.1(e) are derived from the ‘‘National Design Specification for Wood Construction,’’ by AmericanForest and Paper Association, 1991 edition.

In addition to proper selection of the through bolts and lag screws, also follow the follow guidelines:

• Neither through bolts nor lag screws should be used in wood members less than 3½ (89 mm) in leastdimension.

• Dimensionally locate through bolts and lag screws with respect to structural members per Fig. 3.2.1.2(i).

• Predrill holes for through bolts 1⁄32 or 1⁄16 in. (0.8 or 1.6 mm) larger in diameter than the bolt diameter.

Fig. 3.2.1.2(g). Special threaded pipe fitting for attachment of sway brace to structure.



• Predrill lead holes for lag screws in accordance with Table 3.2.1(c) and Fig. 3.2.1.2(j).

• Install lag screws properly, by turning them with a wrench, not driving them with a hammer.

Fig. 3.2.1.2(h). Detail of connection of sway brace to side of wood beam with through bolt.

Fig. 3.2.1.2(i). Dimensional locations for lag screws and through bolts in wood.



Table 3.2.1(c) Hole Dimensions for Lag Screws

Length of lag Screw,L, in. (mm)

Depth of shank hole,S, in. (mm)

Depth of lead hole,*in. (mm)

3 (76) 1 (25) 2¾ (70)4 (102) 11⁄2 (38) 3¾ (96)5 (127) 2 (51) 4¾ (121)6 (152) 21⁄2 (64) 5¾ (146)7 (178) 3 (76) 6¾ (172)8 (203) 31⁄2 (89) 7¾ (197)

*Use lead hole boring only.

Attachment to Steel Structural Members. Through bolts in drilled holes or welded studs are suitable for usewith solid steel structural members. Do not use powder-driven fasteners or c-clamps to attach sway brac-ing to steel structural members. Table 3.2.1(f) (Table 3.2.1(i) for metric) gives maximum load values for throughbolts, corresponding to the bolt configuration with respect to the structural member, and the applied horizon-tal seismic load (either H or H/2, depending on sway bracing configuration), for the worst-case angle fromthe vertical for the range of angles given. In other words, seismic design load H or H/2 should not exceed thetable values for the bolt size and configuration selected.

Welded studs should be installed in accordance with American Welding Society standard D1.1, StructuralWelding Code. Stud load-carrying capabilities should be adequate for the anticipated seismic load H.

For attachment to other types of steel structural members, such as ‘‘C’’ or ‘‘Z’’ purlins, trusses or joists, theadequacy of the structural member and the point of attachment to carry the anticipated load needs to bedetermined as part of the system design and should be included with the system design information.

Attachment to Concrete Components. Do not use powder-driven fasteners to attach sway bracing to concretecomponents of the structural system. Such fasteners have not proven to be reliable due to their inability toremain in place during the dynamic loading that occurs during an earthquake.

Expansion anchors may be used to attach sway bracing to concrete structural components. Because of themany variations in anchor types, concrete strengths, and the lack of dynamic test performance for con-crete fasteners, it is impractical here to provide detailed requirements with respect to anchor sizing and loadcapacities. Expansion anchors may be selected from a given manufacturer’s product line if they meet allof the following conditions:

Fig. 3.2.1.2(j). Pilot hole sizing for lag screws−use with Table 3.2.1(c).



a. the expansion anchors should have local governing jurisdiction-approved values equal to or greaterthan both the shear and tension capacities listed in Table 3.2.1(k). (An example of a local governing juris-diction would be the International Conference of Building Officials (ICBO) evaluation services guide.)

Note that FMRC-Approved expansion anchors are rated on the basis of their capacity for use with sprinkler hangers of the same size, andmay or may not be capable of meeting these minimum shear and tension values. Also, note that the intent of specifying these minimum val-ues is to take into account the lack of any dynamic test performance for these devices and to incorporate some safety factor screeningto ensure a minimum performance level. Cast-in-place concrete inserts may be used in place of expansion anchors if the governingjurisdiction-approved loads for the inserts are greater than or equal to the values for the specified expansion anchors.

b. the relationship between actual calculated shear and tension loads, and allowable shear and tensionloads, should conform to the following equation:

(SACT/SALL) + (TACT/TALL) ≤ 1.0

where

SACT = calculated actual shear load using Fig. 3.2.1.2(a) through (f)

SALL = local governing jurisdiction-approved shear load

TACT = calculated actual tension load using Fig. 3.2.1.2(a) through (f)

TALL = local governing jurisdiction-approved allowable tension load

c. verification of the capability of the structural member and the point of attachment to withstand the antici-pated load should be included with the system design information.

d. all details of the installation should be in conformance with the manufacturer’s instructions and anyguidelines established by the local governing jurisdiction as part of their load ratings, including any inspec-tion requirements or certification of concrete strength.

Table 3.2.1(k). Minimum Shear and Tension Capacities for Concrete Anchors

Anchor Size,in. (mm)

Shear Capacity,lb (N)

Tension Capacity,lb (N)

3⁄8 (9.5) 675 (3000) 615 (2735)1⁄2 (13) 1130 (5025) 1040 (4625)5⁄8 (16) 1580 (7030) 1535 (6830)3⁄4 (19) 2270 (10095) 2020 (8985)7⁄8 (22) 5050 (22505) 3705 (16480)

2. Attachment to Sprinkler Piping. Connections to the sprinkler piping can be made with a pipe clamp, aU-bolt which is mechanically fastened to the brace using nuts and washers, or other positive mechanicalmeans of attachment. Pipe rings should be avoided because they result in a loose fit. All means of fasten-ing should be capable of carrying the anticipated seismic load. Verification of the load carrying capacity for theattachment to the pipe should be provided with the system design information.

See Fig. 3.2.1.2(k) for examples of bracing attachment to piping.



Fig. 3.2.1.2(k). Examples of Bracing Attachment to Piping.



Table 3.2.1(d). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular to Grain, lb.

ThroughBolt

Diam-eter,in.

Lengthof Bolt inTimber

in.

Configuration A

Brace Angle from Vertical

Configuration B


Configuration C


30-44 45-59 60-90 30-44 45-59 60-90 30-44 45-5960-90(.51-0)

3⁄83½ 460 460 460 265 460 798 230 325 3984 450 450 450 260 450 779 225 318 390

4½ 430 430 430 248 430 745 215 304 372

½

3½ 720 720 720 416 720 1247 360 509 6244 740 740 740 427 740 1282 370 523 641

4½ 720 720 720 416 720 1247 360 509 6245 700 700 700 404 700 1212 350 495 606

5½ 680 680 680 393 680 1178 340 481 5896 650 650 650 375 650 1126 325 460 563

5⁄8

3½ 850 850 850 491 850 1472 425 601 7364 740 740 740 427 740 1282 370 523 641

4½ 720 720 720 416 720 1247 360 509 6245 1040 1040 1040 600 1040 1801 520 735 900

5½ 1020 1020 1020 589 1020 1767 510 721 8836 1000 1000 1000 577 1000 1732 500 707 866

7½ 920 920 920 531 920 1593 460 650 7978 890 890 890 514 890 1542 445 629 771

¾

3½ 950 950 950 548 950 1645 475 671 8234 1050 1050 1050 606 1050 1819 525 742 909

4½ 1180 1180 1180 681 1180 2044 590 834 10225 1300 1300 1300 750 1300 2252 650 919 1126

5½ 1370 1370 1370 790 1370 2373 685 969 11876 1390 1390 1390 803 1390 2408 695 983 1204

7½ 920 920 920 531 920 1593 460 650 7978 1290 1290 1290 745 1290 2234 645 912 1117

9½ 1200 1200 1200 693 1200 2078 600 848 103910 1120 1120 1120 647 1120 1940 560 792 970

7⁄8

3½ 1050 1050 1050 606 1050 1819 525 742 9094 1150 1150 1150 664 1150 1992 575 813 996

4½ 1300 1300 1300 750 1300 2252 650 919 11265 1440 1440 1440 831 1440 2494 720 1018 1247

5½ 1580 1580 1580 912 1580 2737 790 1117 13686 1700 1700 1700 981 1700 2944 850 1202 1472

7½ 1760 1760 1760 1016 1760 3048 880 1245 15248 1740 1740 1740 1005 1740 3014 870 1230 1507

9½ 1650 1650 1650 952 1650 2857 825 1167 142910 1610 1610 1610 930 1610 2789 805 1138 1395



Table 3.2.1(d). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular to Grain, lb. (continued)

ThroughBolt

Diam-eter,in.


in.

Configuration A


Configuration B


Configuration C


30-44 45-59 60-90 30-44 45-59 60-90 30-44 45-5960-90(.51-0)

1

3½ 1140 1140 1140 658 1140 1975 570 806 9874 1260 1260 1260 727 1260 2182 630 890 1091

4½ 1420 1420 1420 820 1420 2460 710 1004 12305 1570 1570 1570 906 1570 2719 785 1110 1360

5½ 1730 1730 1730 999 1730 2296 865 1223 14986 1890 1890 1890 1091 1890 3274 945 1336 1637

7½ 2200 2200 2200 1270 2200 3810 1100 1556 19068 2220 2220 2220 1282 2220 3845 1110 1570 1923

9½ 2150 2150 2150 1241 2150 3724 1075 1520 186210 2110 2110 2110 1218 2110 3654 1055 1491 1828

11½ 2010 2010 2010 1160 2010 3481 1005 1421 174112 1960 1960 1960 1132 1960 3395 980 1386 1698



Table 3.2.1(e). Maximum Horizontal Load for Lag Screws in Wood-Load Perpendicular to Grain, lb.

ThroughBolt

Diam-eter,in.


in.

Configuration A


Configuration B


Configuration C

Brace Angle from Vertical30-44 45-59 60-90 30-44 45-59 60-90 30-44 45-59 60-90

3⁄8

3 304 325 292 168 325 526 230 324 4004 392 354 317 183 354 678 250 352 4355 476 375 336 194 375 824 265 373 4616 564 382 342 196 382 976 270 380 470

½

3 366 — — — — 632 — — —4 473 509 456 264 509 818 360 507 6265 582 545 488 282 545 1008 385 542 6706 689 559 501 288 559 1192 395 556 6878 905 573 513 296 573 1586 405 570 704

5⁄8

3 410 — — — — 716 — — —4 538 — — — — 929 — — —5 687 728 653 277 728 1154 515 725 8966 791 778 697 403 778 1360 550 775 9578 1044 806 723 416 806 1807 570 803 991

7⁄8

3 487 — — — — 843 — — —4 548 — — — — 1122 — — —5 813 — — — — 1407 — — —6 971 — — — — 1630 — — —8 1297 1365 1223 685 1365 2244 965 1359 1678

Table 3.2.1(f). Maximum Horizontal Load for Through Bolts in Steel (bolt perpendicular to mounting surface), lb.

ThroughBolt

Diameter,in.

Configuration A


Configuration B


Configuration C


1⁄4 400 500 600 300 500 650 325 458 5653⁄8 900 1200 1400 800 1200 1550 735 1035 12781⁄2 1600 2050 2550 1450 2050 2850 1300 1830 22605⁄8 2500 3300 3950 2250 3300 4400 2045 2880 3557



Table 3.2.1(g). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular to Grain, N (Metric)

ThroughBolt

Diam-eter,in.


in.

Configuration A


Configuration B


Configuration C


1089 2046 2046 2046 1179 2046 3550 1023 1446 1770

102 2002 2002 2002 1156 2002 3465 1001 1414 1735114 1913 1913 1913 1103 1913 3314 956 1352 1655

13

41 1512 1512 1512 872 1512 2620 756 1068 130851 1868 1868 1868 1081 1868 3234 934 1321 161967 2446 2446 2446 1414 2446 4239 1223 1730 211776 2802 2802 2802 1619 2802 4853 1401 1979 242992 3203 3203 3203 1850 3203 5547 1601 2264 2776

102 3292 3292 3292 1899 3292 5693 1646 2326 2851114 3203 3203 3203 1850 3203 5547 1601 2264 2776127 3114 3114 3114 1797 3114 5391 1557 2202 2695140 3025 3025 3025 1748 3025 5240 1512 2139 2620152 2891 2891 2891 1668 2891 5008 1446 2046 2504

16

89 3780 3780 3780 2184 3780 6547 1890 2673 3274102 3292 3292 3292 1899 3292 5702 1646 2326 2851114 3203 3203 3203 1850 3203 5547 1601 2264 2776127 4626 4626 4626 2669 4626 8011 2313 3269 4003140 4537 4537 4537 2620 4537 7860 2268 3207 3928152 4448 4448 4448 2566 4448 7704 2224 3145 3852191 4092 4092 4092 2362 4092 7086 2046 2891 3545203 3959 3959 3959 2286 3959 6859 1979 2798 3429



Table 3.2.1(g). Maximum Horizontal Load for Through Bolts in Wood-Load Perpendicular to Grain, N (Metric) (continued)

ThroughBolt

Diam-eter,in.


in.

Configuration A


Configuration B


Configuration C


19

89 4226 4226 4226 2438 4226 7317 2113 2985 3661102 4670 4670 4670 2695 4670 8091 2335 3300 4043114 5249 5249 5249 3029 5249 9092 2624 3710 4546127 5782 5782 5782 3336 5782 10017 2891 4088 5008140 6094 6094 6094 3514 6094 10555 3047 4310 5280152 6183 6183 6183 3571 6183 10711 3091 4372 5355191 4092 4092 4092 2362 4092 7086 2046 2891 3545203 5738 5738 5738 3314 5738 9937 2869 4057 4968241 5338 5338 5338 3082 5338 9243 2669 3772 4621254 4982 4982 4982 2878 4982 8629 2491 3523 4315

22

89 4670 4670 4670 2695 4670 8091 2335 3300 4043102 5115 5115 5115 2953 5115 8860 2558 3616 4430114 5782 5782 5782 3336 5782 10017 2891 4088 5008127 6405 6405 6405 3696 6405 11093 3203 4528 5547140 7028 7028 7028 4057 7028 12174 3514 4968 6085152 7562 7562 7562 4363 7562 13095 3781 5346 6547191 7828 7828 7828 4519 7828 13558 3914 5538 6779203 7740 7740 7740 4470 7740 13406 3870 5471 6703241 7339 7339 7339 4234 7339 12708 3670 5191 6356254 7161 7161 7161 4137 7161 12405 3581 5062 6205

25

89 5071 5071 5071 2927 5071 8785 2535 3585 4390102 5604 5604 5604 3234 5604 9706 2802 3959 4653114 6316 6316 6316 3647 6316 10942 3158 4466 5471127 6983 6983 6983 4030 6983 12094 3492 4937 6049140 7695 7695 7695 4444 7695 10213 3848 5440 6663152 8407 8407 8407 4853 8407 14563 4203 5943 7281191 9786 9786 9786 5649 9786 16947 4893 6921 8478203 9875 9875 9875 5702 9875 17103 4937 6983 8554241 9563 9563 9563 5520 9563 16564 4782 6761 8282254 9385 9385 9385 5418 9385 16253 4693 6632 8131292 8940 8940 8940 5160 8940 15483 4470 6321 7744305 8718 8718 8718 5035 8718 15101 4359 6165 7553



Table 3.2.1(h). Maximum Horizontal Load for Lag Screws in Wood-Load Perpendicular to Grain, N (Metric)

ThroughBolt

Diam-eter,in.


in.

Configuration A


Configuration B


Configuration C


10

76 1352 1446 1299 747 1446 2340 1023 1441 1779102 1744 1575 1410 814 1575 3016 1112 1566 1935127 2117 1668 1495 863 1668 3665 1179 1659 2051152 2509 1699 1521 872 1699 4341 1201 1690 2091

13

76 1628 — — — — 2811 — — —102 2104 2264 2028 1174 2264 3638 1601 2255 2784127 2589 2424 2171 1254 2424 4484 1712 2411 2980152 3065 2486 2228 1281 2486 5302 1757 2473 3056203 4025 2549 2282 1317 2549 7054 1801 2535 3131

16

76 1824 — — — — 3185 — — —102 2393 — — — — 4132 — — —127 3056 3238 2905 1232 3238 5133 2291 3225 3985152 3518 3461 3100 1793 3461 6049 2446 3447 4257203 4644 3585 3216 1850 3585 8036 2535 3572 4408

22

76 2166 — — — — 3750 — — —102 2438 — — — — 4991 — — —127 3616 — — — — 6258 — — —152 4319 — — — — 7250 — — —203 5769 6072 5440 3049 6072 9981 4292 6045 7464

Table 3.2.1(i). Maximum Horizontal Load for Through Bolts in Steel (bolt perpendicular to mounting surface), N

ThroughBolt

Diameter,in.

Configuration A


Configuration B


Configuration C


6 1780 2224 2669 1334 2224 2891 1446 2037 251310 4003 5338 6227 3558 5338 6894 3269 4604 568513 7116 9118 11342 6450 9118 12677 5782 8140 1005216 11120 14678 17570 10008 14678 19571 9096 12810 15821



3.2.2 Flexibility

3.2.2.1 General

This section provides guidelines and techniques for achieving flexibility between portions of a properly bracedwelded and non-welded sprinkler systems which are expected to move differentially with respect to eachother. Two techniques are described: 1) use of flexible couplings, and 2) use seismic separation assem-blies where any sprinkler system piping crosses building seismic separation joints above ground level.

NOTE: If more flexible couplings are installed than recommended in this section, provide additional lateral sway bracing within24 in. (0.6 m) of every other such flexible coupling on straight runs of pipe and every such flexible coupling at changes in hori-zontal pipe direction to prevent excessive movement of piping (see Section 3.2.1). Locate sway bracing so that no more than twoflexible couplings (one of which is within 24 in. (0.6 m) of sway bracing) are located between sway bracing locations.

Where welded piping systems exist from the riser through the crossmains, a flexible coupling should beprovided within 24 in. (0.6 m) of the bottom of single-story risers, and within 24 in. (0.6 m) of the bottom andas needed to satisfy Section 3.2.2.2, item 2, for multistory risers. Also, seismic separation assemblies areneeded for piping which crosses building seismic expansion joints per Section 3.2.2.7.

For non-welded systems or portions of systems, apply the guidelines following in Sections 3.2.2.2 through3.2.2.7.

3.2.2.2 Sprinkler Riser

Provide flexible couplings:

1. Within 24 in. (0.6 m) of the top and bottom of each riser (see Fig. 3.2.2.2 [a] for details). This applies to ris-ers located outside and inside buildings. When multiple risers are supplied by a single manifold connec-tion to an underground main, each riser should be provided with flexible couplings at the top and at the bottomwhere connected to the manifold. The horizontal manifold piping should be no more than 3 ft (0.9 m) abovefloor level and adequately braced when needed (see 3.2.1.2, Step 1, item 1). The horizontal manifold con-nection to the main riser and the main riser connection to the riser stub at floor level should be made withflanged or other rigid connections (see Fig. 3.2.2.2[b]).

2. For multistory building risers where clearances meet the recommendations of Section 3.2.3.1, an addi-tional flexible coupling is needed at each floor level. The flexible coupling should be within 12 in. (0.3 m) ofthe floor (either above or below the floor). See Fig. 3.2.2.2(d).

Where clearances per Section 3.2.3.1 are not provided, flexible couplings should be provided within 12 in.(0.3 m) above and below the floor. The flexible coupling below the floor should be below any main supply-ing that floor.

Flexible couplings are not needed beneath floors which rest directly on the ground; however a flexible couplingis needed above the ground floor as recommended in 1) above.

3. Within 24 in. (0.6 m) above or below any intermediate points of lateral restraint for risers.

3.2.2.3 Feedmains/Crossmains


1. Within 24 in. (0.6 m) above or below of intermediate points of lateral restraint for vertical pipe.

2. Within 24 in. (0.6 m) of the top and bottom of vertical pipe runs 6 ft (1.8 m) or greater in length (inconjunction with the sway bracing recommended in Section 3.2.1.2, Step 1, item 2).

3. Provide a seismic separation assembly per Section 3.2.2.7 where any piping crosses a seismic buildingexpansion joint.

4. Where clearances per Section 3.2.3.1 are not provided, flexible couplings should be provided within 12 in.(0.3 m) of each side of a wall.

3.2.2.4 In-Rack Sprinkler Systems

Provide flexibility per the following guidelines.



(Note that flexibility provisions for piping portions within the rack itself are made on the assumption that noin-depth analysis has been made of the rack system and how it will move during an earthquake. Provid-ing this level of protection may not prevent leakage due to rack collapse or excessive movement beyond thecapabilities of the flexible couplings. For example, high racks with multiple levels of in-rack sprinklers mayexperience differential movement in excess of the capability of a single flexible coupling.)

1. Provide a flexible coupling within 24 in. (0.6 m) of the top and bottom of each in-rack sprinkler systemriser, for both cases when the riser may be attached directly to the ceiling sprinkler system riser (seeFig. 3.2.2.2[c]), or when the in-rack sprinkler system riser is attached directly to the underground piping.Details of flexibility at the top of the riser may be the same as for sprinkler systems, as shown in Fig.3.2.2.2(a).

2. Provide a flexible coupling within 24 in. (0.6 m) above or below intermediate points of lateral restraint ofthe riser, or other vertical pipe. (See Fig. 3.2.2.4).


4. Provide a flexible coupling within 24 in. (0.6 m) above the initial in-rack sprinkler pipe drop attachmentto the rack (see Fig. 3.2.2.4).

Fig. 3.2.2.2(a). Flexible coupling and four-way sway bracing details for riser. NOTE: for risers located outside of build-ings, Detail A or B may be used with the bracing attached to a structural element.



5. Provide a flexible coupling within 24 in. (0.6 m) of the connection of pipe drops to overhead piping orarmovers (see Fig. 3.2.2.5).

6. Provide a flexible coupling on the horizontal portion of in-rack sprinkler piping within 24 in. (0.6 m) of theconnections to vertical pipe drops (see Fig. 3.2.2.4).

7. When pipe drops supplying in-rack sprinklers are connected to overhead horizontal piping via an armover,no flexible couplings are needed on the armover. However, a hanger of the type that will resist vertical move-ment is needed within 24 in. (0.6 m) of the drop regardless of armover length. (See Fig. 3.2.2.4).

3.2.2.5 Pipe Drops to Below Suspended Ceilings, Mezzanines, Walkways, etc.


1. Within 24 in. (0.6 m) of the connection to overhead piping or armovers for pipe drops exceeding 2 ft (0.6 m)in length and which supply more than one sprinkler (see Fig. 3.2.2.5). This does not apply to individual pipedrops which supply one sprinkler.

2. On the horizontal portion within 24 in. (0.6 m) of any tee or elbow connecting pipe drops to sprinkler pip-ing beneath ceilings, mezzanines, walkways, etc. which supply more than one sprinkler (see Fig. 3.2.2.5).

3. Within 24 in. (0.6 m) above and/or below any intermediate points of lateral restraint when needed to accom-modate differential movement and which supply more than one sprinkler.

4. When pipe drops are connected to overhead horizontal piping via an armover, no flexible couplings areneeded on the armover. However, a hanger is needed within 24 in. (0.6 m) of the pipe drop on all armoverssupplying more than one sprinkler, regardless of armover length. Hangers are needed on armovers within

Fig. 3.2.2.2(b). Arrangement of manifolded risers.



24 in. (0.6 m) of pipe drops supplying only one sprinkler when the armover exceeds 24 in. (0.6 m) in length.(See Fig. 3.2.2.5). All hangers should be the type that resist vertical movement.

3.2.2.6 Piping for Hose Racks/Headers


1. Within 24 in. (0.6 m) of the top and bottom of each dedicated hose system riser (see Fig. 3.2.2.2[c] fordetails), when the riser is attached directly to a sprinkler system riser. If the riser is attached directly to theunderground piping, then provide flexibility the same as for a sprinkler riser (see Fig. 3.2.2.2[a]).


3. Within 24 in. (0.6 m) of the connection to overhead horizontal piping for pipe drops greater than 2 ft (0.6 m)in length.

Fig. 3.2.2.2(d). Arrangement of flexible couplings for risers passing through floors of multistory buildings.



3.2.2.7 Seismic Separation Assemblies

Install seismic separation assemblies on all fire protection system piping which crosses a seismic buildingexpansion joint (including separations between two buildings) above ground level. Fig. 3.2.2.7 illustrates anacceptable arrangement of piping, flexible couplings and elbows for 4 in. (100 mm) piping crossing an 8 in.(200 mm) separation. When other pipe sizes or separation distances are used, the sizes and dimensions ofequipment may differ. Other engineered methods which provide a comparable degree of flexibility are alsoacceptable.

3.2.3 Clearance

3.2.3.1 Clearance Around Piping Through Walls or Floors

Where piping passes through walls, platforms, mezzanines or floors, clearance should be provided so thatthe piping will not be damaged by impact due to differential movement. Provide minimum clearances of 1 in.

Fig. 3.2.2.2(c). Arrangement of combination risers for ceiling sprinklers and in-rack-sprinklers/hose stations.



(25 mm) for pipes 1 in. (25 mm) diameter through 31⁄2in. (89 mm), and 2 in. (50 mm) for pipe sizes 4 in. (100mm) and larger. Openings may be sealed with mastic or a weak, frangible mortar. If the pipe passes througha fire separation, the space can be filled with mineral wool held in place with a pipe collar.

Clearance is not needed when wall material is frangible, such as gypsum board, and the wall is not requiredto have a fire rating.

Fig. 3.2.2.4. Arrangements for piping feeding in-rack sprinklers.



Fig. 3.2.2.5. Arrangement for pipe drops supplying sprinklers below ceilings, mezzanines, walkways, etc.



Fig. 3.2.2.7. Seismic separation assembly for fire protection system piping that crosses a seismic building expansion jointabove ground level (Source: Data Sheet 2-8N, from NFPA by permission.)



3.2.3.2 Clearance Between Piping and Walls/Structural Members

Provide at least 2 in. (51 mm) clearance as follows:

1. between ends of piping and walls/structural members

2. when piping passes through walls/structural members, then turns 90 degrees to run parallel to the wall,between the parallel pipe run and the wall

3. when piping passes through walls/structural members, between any flanges, fittings or other devices onthe piping and the wall.

3.2.4 Anchorage

3.2.4.1 General

Anchorage is needed for storage racks with in-rack sprinklers, and for suspended ceilings with sprinklersbeneath. Other items should be anchored if they expose the fire protection system piping to damage byimpact.

3.2.4.2 Storage Racks with In-rack Sprinklers

Documentation should be obtained to verify that rack anchorage and rack design meets the Uniform Build-ing Code or other code requirements for seismic design for the seismic zone involved. In the absence ofsuch verification, a seismic analysis should be made by qualified personnel, and any resulting recom-mended improvements should be made. Bolting the racks to the floor, cross bracing between racks, and othertechniques should be employed as necessary.

3.2.4.3 Suspended Ceilings

Anchor/brace suspended ceilings that have sprinklers below. One acceptable method is to provide compres-sion struts and diagonal bracing wire at a 45 degree angle in all four directions, on 12 ft (3.7 m) centers,and provide at least a 1⁄2 in. (13 mm) gap around ceiling penetrations for sprinklers. Other methods whichprovide suitable anchorage may be used, such as those described in Uniform Building Code 1636, NEHRP(National Earthquake Hazard Reduction Program) Provisions for Seismic Regulations for New Buildings,or ASCE (American Society of Civil Engineers) Standard 7, Minimum Design Loads for Buildings and OtherStructures.

3.2.4.4 Other Equipment

Anchor/brace all other equipment which may impact the sprinkler system. Such equipment may include butis not limited to, HVAC equipment (i.e. ductwork, defusers, heaters, etc.), conveyors, cable trays, etc.

3.2.5 Pipe Joining Methods

3.2.5.1 General

Welded or rigid pipe connections should be used, except when flexible couplings are specificallyrecommended per Section 3.2.2. This includes all branch line and branch line riser nipple connections tocrossmains, branch line connections to riser nipples, and the two connections for any take-out piping installedon gridded branch lines to facilitate flushing investigations. Unless specifically recommended in Section 3.2.2,use of extra flexible couplings will necessitate additional lateral sway bracing per Section 3.2.1.2, Step 1,item 5.

Note that plain-end fittings are acceptable for use in areas where earthquake protection is required. Plain-end fittings are one-piece devices into which pipe ends are inserted and held in place by set screws whichhave a torque-indicating means to ensure proper torque has been applied to the set screws. Plain-end cou-plings, on the other hand, consist of two semicircular halves which fit together to connect pipe ends and haveno such torque indication devices. They are not FMRC-Approved, and thus unacceptable for any sprinklerinstallation.



3.2.6 Type, Attachment and Locations of Hangers

3.2.6.1 General

Hanger guidelines contained in Data Sheet 2-8N, Installation of Sprinkler Systems, are acceptable with thefollowing exceptions:

1. Do not use powder-driven fasteners to attach hangers to the building structure.

2. Locate hangers on branch lines at least 6 ft (1.8 m) from the branch line connection to the crossmain,or to the branch line riser nipple which connects to the crossmain.

3. Provide hangers of the type that resist vertical movement: a) on all armovers which supply vertical pipedrops which supply more than one sprinkler, regardless of the length of the armover, located within 24 in.(0.6 m) of the drop, and b) on all armovers greater than 24 in. (0.6 m) long which supply one sprinkler, locatedwithin 24 in. (0.6 m) of the drop. Note that for very long armovers, hangers in addition to those recom-mended here will be needed when normal hanger spacing rules apply.

4. All c-clamp hangers should have retaining straps to minimize the potential for the c-clamp from slippingoff the structural member.

5. When u-hooks are used on branchlines, they should be wraparound type (or otherwise arranged to preventpipe from bouncing upward) for: a) every other hanger on gridded branchlines, and b) the last hanger ondead-end branch lines, including outrigger lines on gridded systems.

6. To minimize potential damage from impact, the hanger closest to any upright sprinkler which is locatedwithin 2 in. (51 mm) both horizontally and vertically of a structural or non-structural element should be a typethat resists vertical movement.

7. Hangers for in-rack sprinkler piping should be of the type which resist vertical pipe movement. In no caseshould there be more than one half in. (51 mm) of space between the top of the pipe and the hanger’s pointof vertical resistance. Attachment to the rack structure should be by positive mechanical attachment whichprovides positive resistance to vertical movement, and does not allow the hanger to slip sideways off the pointof attachment. All c-clamps should have retaining straps.

3.2.7 Pipe Material

3.2.7.1 General

Nonmetallic pipe should not be used in aboveground installations.

3.3 Standpipes

3.3.1 General

Seismic consideration for standpipes include flexibility, clearance and bracing. Treat standpipes the sameas sprinkler system risers with regard to sway bracing, flexibility, and clearance. When hose outlets are fedfrom pipe which penetrates walls or floors, provide flexibility, clearance around the piping, and clearancebetween the piping and walls the same as for sprinkler pipe.

3.4 Water Spray Systems

3.4.1 General

Seismic considerations for waterspray systems include sway bracing, flexibility, and clearance. Generally,seismic protection guidelines may be applied on the same basis as for sprinkler systems. However, specialapproaches for sway bracing design and attachment of sway bracing to the equipment or structure may benecessary depending on the nature of the particular system and the equipment being protected by the water-spray system.



3.5 Foam-Water Sprinkler Systems

3.5.1 General

Seismic considerations for foam-water sprinkler systems include sway bracing, flexibility and clearance.Seismic protection guidelines with respect to the piping should be applied on the same basis as for ordi-nary sprinkler systems. In addition, foam-making equipment, such as tanks, pumps etc. should have appro-priate flexibility, clearance and anchorage/restraint to protect against damage that may result from differentialmovement between different portions of the system and/or structural and non-structural elements.

3.6 Fire Pump Installations

3.6.1 General

Seismic considerations for fire pump installations include the following: 1) sway bracing of piping which maybe expected to move differentially with respect to the structure, 2) flexibility on piping systems or otherequipment where differential movement between portions of piping systems or equipment may be expected,3) clearance between pipe and wall or floor penetrations, 4) anchorage and/or bracing of pumps, control-lers, starting batteries and fuel tanks, and 5) emergency power for jockey pumps and for electric drive firepumps.

Apply the following guidelines.

3.6.2 Sway Bracing

Provide four-way sway bracing for any vertical riser piping which extends from the pump to discharge throughthe ceiling to floors above. Provide horizontal overhead piping and piping on pipe stands with two-way lateraland longitudal sway bracing. Design sway bracing on the same basis as for sprinkler system piping. Attach-ment points for the sway bracing should be made at structural elements capable of carrying the seismic loads.

3.6.3 Flexibility

Suction and Discharge Piping. When the pump house rests directly on the ground and suction or dischargepiping enters or exits through the floor, and no clearance around the piping is provided, flexible couplingsare unnecessary because the pump house floor is not expected to move differentially from the ground. Whenthe fire pump and driver, including suction and discharge piping, are located above grade in a building, flex-ibility should be provided on the suction and discharge piping on the same basis as for sprinkler system pip-ing. Flexible couplings are not needed for pipe penetrations which feed hose headers or relief valve dischargeoutlets on an outside wall.

Engine Fuel Line Connections. Provide flexibility on fuel line connections to both the fire pump drivers andthe fuel tanks which supply fire pump drivers.

Other Equipment. Flexibility for other equipment is generally unnecessary if proper anchorage and/or restraintagainst horizontal or vertical motion exists.

3.6.4 Clearance

Provide at least 2 in. (51 mm) of clearance around piping penetrations through structural floors, walls orceilings.

3.6.5 Anchorage

Provide anchorage for various components as follows:

Fire Pump and Driver. Anchor the base plates for the pump and driver to the pump house floor.

Controller. Anchor the controller to the floor and or/wall to prevent damage due to differential movement.Make sure that any piping (such as to a pressure switch) or electrical connections between the controller andother equipment are not exposed to breakage or separation.



Fuel Tanks (Internal Combustion Engines). Anchor a fuel tank to its frame or directly to the floor and/or wallif floor mounted. The frame should also be adequately braced to prevent buckling of the legs and alsoanchored directly to the floor. Piping connections between the fuel tank and engine should not be exposedto breakage or separation.

Starter Batteries (Internal Combustion Engines). Restrain the battery set and anchor the battery racks toprevent sliding and/or overturning which could damage the connection from the battery set to the engine.Battery racks should be adequately braced to prevent buckling of the legs.

Other Equipment. Anchor any other unrestrained equipment in the pump house if it exposes any of the firepump equipment to damage from impact due to uncontrolled differential movement such as sliding, over-turning or swinging.

3.6.6 Emergency Electric Power Supply Connection

When emergency electric power supplies are available on site, jockey pumps should be connected. Also, ifthe emergency power supply is arranged to supply emergency electric power to the electric motor drivingthe fire pump, then the emergency power supply should be provided with full seismic protection. In mostinstances, the emergency power supply will be a diesel-engine powered generator. In those cases, provideseismic protection for all equipment in the same manner as described above for internal combustion engineswhich drive fire pumps.

3.7 Water Storage Tanks and Reservoirs

3.7.1 General

Water tanks and reservoirs fall into three categories:

1. Ground level tanks which either provide a suction supply for an adjacent fire pump, or act as a gravitytank to provide sufficient water pressure for the fire protection system. These are the most common type inareas where seismic protection is required. Only tanks which are FMRC-Approved for seismic zones 150or less should be installed. Note that seismic Approval covers the tank and not the foundation. Guidelines forearthquake protection of tanks are provided in the following sections.

For ground level tanks, there are four main seismic considerations: 1) flexibility of pipe connections to tank,2) anchorage of the tank and foundation to prevent horizontal and vertical displacement, 3) clearance aroundpipe penetrations through pump house or other structural walls, and 4) proper steel thickness near baseof tank to avoid elephant-footing. (Using an FMRC-Approved tank for the appropriate seismic zone will accom-plish this).

In strong ground shaking areas, unanchored tanks may have significant vertical and horizontal displace-ments. Depending on the diameter of the tank and the height-to-diameter ratio, these expected displace-ments may vary. However, the main point is that unanchored tanks may create displacements that may notonly damage the tank, but also rupture the attached piping.

2. Elevated tanks, where the tank body is mounted on legs or a pedestal. These types of tanks are rare inareas where seismic protection is required. Because of the complexity of any seismic analysis for these typesof tanks, they are not addressed in this data sheet. When encountered, seismic analysis by a qualified struc-tural engineer should be recommended.

3. Embankment supported fabric tanks, where a lined reservoir is supported by an earthen embankment.Only FMRC-Approved tanks should be installed. Because seismic considerations for these types or reser-voirs are complex and are not addressed by the FMRC Approval process, analysis by a qualified structuralengineer should be recommended.

3.7.2 Flexibility

Provide flexible couplings as follows:

1. When the tank discharge pipe runs horizontally to a pump, provide two flexible couplings on the pipebetween the tank and the pump. One should be as close to the tank wall as possible and the other within24 in. (0.6 m) of the pump.



2. When the tank discharge pipe feeds into an underground main, provide two flexible couplings betweenthe tank and the ground entrance. One should be as close to the tank wall as possible. The other should bewithin 24 in. (0.6 m) of the ground entrance.

3.7.3 Anchorage for Tank and Foundation

All new ground level tanks should be anchored and FMRC-Approved for seismic protection, for the appro-priate seismic zone. Additionally, the foundation design, which is often done separately from the tank design,should be coordinated with the tank design to ensure that the foundation is of sufficient size and mass to pre-vent rocking of the tank. Anchorage and foundation design details should be provided and/or reviewed bya qualified structural engineer.

Existing ground level tanks which are unanchored and/or are not FMRC Approved for seismic protectionshould be evaluated as to the need for provision of anchorage and/or flexibility by a qualified structural engi-neer. American Water Works Association Standards D100, Standard for Welded Steel Tanks for Waster Stor-age, and D103, Standard for Factory-Coated Bolted Steel Tanks for Water Storage, provide seismic designcriteria for anchorage of tanks.

3.7.4 Clearance

Provide at least 2 in. (51 mm) clearance on all sides of piping which passes through structural walls or otherfixed structures.

3.8 Fire Protection System Plans and Calculations

3.8.1 General

In addition to the plans and/or calculations normally required for fire protection systems, plans, calculations,and equipment information should be provided for all earthquake protection features of the fire protection sys-tems, including the following items:

1. Sway bracing details:• sway bracing locations indicating the type of sway bracing being provided,• sway bracing calculations showing horizontal seismic design load requirements, with indication of zone

of influence for each bracing location,• schedule of sway bracing type, size and design criteria (length, angle from vertical, and load capacities),

and• details of attachment to structure and to piping, including verification of structural capacity to withstand

seismic load, details of sizing and load capacities of fasteners, and verification of load capabilities ofconcrete anchors (if used).

2. Location of flexible couplings and seismic separation assemblies.

3. Location of clearances around piping for seismic purposes.

4. Anchorage or seismic design details for storage racks which have in-rack sprinklers.

5. Anchorage or seismic design details for suspended ceilings beneath which sprinklers are installed.

6. For fire pump installations, all seismic design details as outlined in Section 3.6.

7. For water storage tanks or reservoirs, all seismic design details as outlined in Section 3.7.

3.9 Examples of Sway Bracing Design

3.9.1 Examples

Fig. 3.9.1 shows a plan view of a building having three separate occupancies, and three types of sprinklersystems, which will all be used as examples to illustrate the concept of sway bracing design for sprinkler sys-tems described in section 3.2.1., Sway Bracing. All three risers are located in the same area, which would



be typical when a single underground lead-in would be used to supply all the risers. Because of this arrange-ment, sway bracing considerations will have to address changes in directions and long feedmains for Sys-tems Nos. 1 and 2. Note that the layout in the examples incorporates maximum allowable spacings betweenbraces in some instances and lesser spacings in others, with symmetrical zones of influence where pos-sible. In reality, sway bracing locations will be determined equally by both the sway bracing location criteriain Section 3.2.1, and the locations of structural members which will serve as the points of attachment forthe sway bracing. Nonuniform spacings will commonly occur because of either of these considerations.

3.9.2 Gridded System—System No. 1

Step 1. Layout and orientation of braces. Fig. 3.9.2.1 shows the layout of the two-way lateral braces, anda four-way brace at the riser. Fig. 3.9.2.2 shows the layout of the two-way longitudinal braces. In both fig-ures, the dashed lines indicate the zone of influence for piping to be used to calculate horizontal seismicdesign load for each bracing location. In this example, the location of lateral and longitudinal sway bracing onthe actual piping grid is fairly straightforward. However, because of the long feedmain, and the changes indirection, lateral bracing is strategically located within 24 in. (06 m) of the changes of direction, and will beused both as lateral bracing on the pipe to which it is attached, and as longitudinal bracing for the run of pip-ing after the change in direction. This will be illustrated in Step 2, following.

Step 2. Calculate design load requirements. For the purpose of this example, a horizontal acceleration0.5 G will be used for calculation purposes. Assume sprinkler piping is schedule 10. Using weights per lengthof water-filled pipe from Table 3.2.1(a), horizontal seismic design loads for each sway bracing location canbe determined as shown in Table 3.9.2.

Step 3. Select the proper brace type, size and maximum length. Based on the configuration of the braceconnection to the structure, the angle of the brace from the vertical, and the calculated horizontal designload, the brace type, size and maximum length can be selected from Table 3.2.1(b).

Step 4. Using the Step 2 design loads, and the brace angle from the vertical, select the appropriatetype and size of fastener for attachment to the building structure.

Fig. 3.9.1. Example of building with three sprinkler risers and three types of sprinkler system configurations.



Fig. 3.9.2.1. Layout and zones of influence for lateral and four-way riser sway bracing for System #1.



Table 3.9.2. Horizontal Seismic Design Loads for System No. 1

Brace Location Nominal Diameter,in. (mm)

Number x Length, ft (m)sWeight/Length, lb/ft (N/m) x G =

Force, lb (N)

1. Riser Bracing (RB)Lateral

Longitudinal

6(152)

6(152)

1 x 30 x 23.0 x 0.5 =(1 x 9.2 x 338 x 0.5) =1 x 20 x 23.0 x 0.5 =1 x 6.1 x 338 x 0.5 =

==

1 x 30 x 23.0 x 0.5 =(1 x 9.2 x 338 x 0.5) =1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

==

345 lb(1555 N)230(1030 N)575 lb(2585 N)

345 lb(1555 N)460(2060)805 lb(3615 N)

(The riser bracing will need to be designed to withstand simultaneously a 575 lb (2585 N) lateral and 805 lb (3615 N)longitudinal horizontal seismic load.)

2. Feedmain Bracing

Fig. 3.9.2.2. Layout and zones of influence for longitudinal and four-way riser sway bracing for System #1.



A-lateral lb 6(152)

1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

460(2060 N)

B-lateral(on leg 1)

longitudinal(on leg 2)

6(152)

6(152)

1 x 20 x 23.0 x 0.5 =(1 x 6.1 x 338 x 0.5) =

1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

==

230 lb(1030 N)

460(2060 N)690 lb(3090 N)

(Brace B is a lateral brace on leg 1, but is also acting as longitudinal brace for 40 ft [12.2 m] of leg 2 [assuming braceis located within 24 in. (0.6 m) of change in direction]. Thus, design should be for total of 690 lb. [3090 N].)

C-lateral(on leg 2)

longitudinal(on leg 1)

6(152)

6(152)

1 x 20 x 23.0 x 0.5 =(1 x 6.1 x 338 x 0.5) =

1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

==

230 lb(1030 N)

460(2060 N)690 lb(3090 N)

(Brace C is a lateral brace on leg 2, but is also acting as a longitudinal brace for leg 1 (assuming brace is locatedwithin 24 in. (0.6 m) of change in direction). This design should be for total of 690 lb. (3090 N).

D-lateral 6(152)

1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

460 lb(2060 N)

E-lateral(on leg 2)

-longitudinal(on near crossmain)

6(152)

6(152)

1 x 20 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

==

230 lb(1030 N)

460 lb(2060 N)690 lb(3090 N)

(Brace E is a lateral brace on leg 2, and also acts as a longitudinal brace for 40 ft (12.2 m) of the near crossmain.Thus, design should be for total of 690 lb. (3090 N).F-longitudinal(on leg 2)

-lateral

(on near crossmain)

6(152)

6(152)

2(51)

1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

1 x 15 x 23.0 x 0.5 =(1 x 4.6 x 33 x 0.5) =

2 x 100 x 4.2 x 0.5 =(2 x 31 x 62 x 0.5) =

==

460 lb(2060 N)

173 lb(777 N)

420(1922)1053 lb(4759 N)

(Brace F is a longitudinal brace for leg 2, and also a lateral brace for 20 ft (6.1 m) of crossmain and two branchline onthe near crossmain. Design is for total of 1053 lb (4759).

3. Crossmain BracingK-lateral 6

(152)

2(51)

1 x 25 x 23.0 x 0.5 =(1 x 7.6 x 338 x 0.5) =

3 x 100 x 4.2 x 0.5 =(3 x 31 x 62 x 0.5) =

==

288 lb(1284 N)

630(2883)918 lb(4167 N)



Q-lateral 4(102)

2(51)

1 x 25 x 11.8 x 0.5 =(1 x 7.6 x 173 x 0.5) =

3 x 100 x 4.2 x 0.5 =(3 x 31 x 62 x 0.5) =

==

148 lb(657 N)

630(2883)778 lb(3450 N)

(Braces K and Q are provided at ends of crossmain to laterally brace crossmain and branchlines in zone of influence,with design loads as indicated.)

L-lateral 4(102)

2(51)

1 x 15 x 11.8 x 0.5 =(1 x 4.6 x 173 x 0.5 =

2 x 100 x 4.2 x 0.5 =(2 x 31 x 62 x 0.5) =

==

89 lb(398 N)

420(1922)509 lb(2320 N)

(Brace L is also an end-of-crossmain brace, with a combined crossmain/branchline design of 593 lb [2699 N].)

G-lateral

M-lateral

6(152)

2(51)

4(102)

2(51)

1 x 30 x 23.0 x 0.5 =(1 x 9.1 x 338 x 0.5) =

3 x 100 x 4.2 x 0.5 =(3 x 31 x 62 x 0.5) =

==

1 x 30 x 11.8 x 0.5 =(1 x 9.1 x 173 x 0.5) =

3 x 100 x 4.2 x 0.5 =(3 x 31 x 62 x 0.5) =

==

345 lb(1538 N)

630(2883)975 lb(4421 N)

177 lb(787 N)

630(2883)807 lb(3670 N)

(Braces G and M are lateral braces which could be spaced up to 40 ft (12.2 m) apart, but because of sway bracing loca-tion layout, are only bracing 30 ft (91.1 m) of crossmain and three branchline portions, with design loads as indicated)H,I,J-lateral 6

(152)

2(51)

1 x 40 x 23.0 x 0.5 =(1 x 12.2 x 338 x 0.5) =

4 x 100 x 4.2 x 0.5 =(4 x 31 x 62 x 0.5) =

==

460 lb(2062 N)

840(3844)1300 lb(5906 N)

N,O,P-lateral 4(102)

2(51)

1 x 40 x 11.8 x 0.5 =(1 x 12.2 x 173 x 0.5) =

4 x 100 x 4.2 x 0.5 =(4 x 31 x 62 x 0.5) =

==

236 lb(1055 N)

840(3844)1076 lb(4899 N)

(Braces H, I, J, N, O and P are lateral braces at maximum 40 ft (12.2 m) spacing, with crossmain/branchline portionsand design loads as indicated.)



R,S-longitudinal

T,V-longitudinal

U, longitudinal

6(152)

4(102)

4(102

1 x 80 x 23.0 x 0.5 =(1 x 24.4 x 338 x 0.5) =

1 x 65 x 11.8 x 0.5 =(1 x 19.8 x 173 x 0.5) =

1 x 55 x 11.8 0.5 =1 x 16.8 x 173 x 0.5) =

920 lb(4124 N)

384 lb(1713 N)

325 lb(1453 N)

(Braces R, S, T, U, and V are longitudinal braces for crossmain portions, with the design loads indicated. Spacingsbetween brace locations is nonuniform for the near and far crossmains because of the use of Brace E for a part of thelongitudinal bracing for the near crossmain.)



3.9.3 Looped System—System No. 2

Step 1. Layout and orientation of braces. Fig. 3.9.3.1 shows the layout of the two-way lateral braces, anda four-way brace at the riser. Fig. 3.9.3.2 shows the layout of the two-way longitudinal braces. Dashed linesindicate the portion of the piping system (zones of influence) to be calculated for each bracing location.

Step 2. Calculate design load requirements. For the purpose of this example, assume a horizontal accel-eration of 0.5G to be applied to the weight of pipe within the zone of influence for each brace. Assume thatsprinkler piping is Schedule 40. Using weights of water-filled pipe from Table 3.2.1(a), horizontal seismicdesign loads for each sway bracing location can be determined as shown in Table 3.9.3.

Step 3. Select the proper brace type, size and maximum length. Based on the configuration of the brace con-nection to the structure, the angle of the brace from the vertical, and the calculated horizontal design load,the brace type, size and maximum length can be selected from Table 3.2.1(b).

Step 4. Using the Step 2 design loads, and the brace angle from the vertical, select the appropriate typeand size of fastener for attachment to the building structure.

Steps 3 and 4. Use same approach as in 3.9.2.

Fig. 3.9.3.1. Layout and zones of influence for lateral and four-way riser sway bracing for System #2.



Fig. 3.9.3.2. Layout and zones of influence for longitudinal and four-way riser sway bracing for System #2.



Table 3.9.3. Horizontal Seismic Design Load Calculations for System No. 2



Force, lb (N)

1. Riser Bracing (RB)Lateral- Longitudinal 6

(152)

6(152)

6(152)

1 x 30 x 31.7 x 0.5 =(1 x 9.1 x 465 x 0.5) =

1 x 20 x 31.7 x 0.5 =(1 x 6.1 x 465 x 0.5) =

==

1 x 30 x 31.7 x 0.5 =(1 x 9.1 x 465 x 0.5) =1 x 35 x 31.7 x 0.5 =(1 x 10.7 x 465 x 0.5) =

==

476 lb(2116 N)

317(1418)793 lb(3534 N)

476 lb(2116 N)555(2488)1031 lb(4604 N)

(The riser bracing will need to be designed to withstand simultaneously a 795 lb (3534 N) lateral and 1031 lb (4604 N)longitudinal horizontal seismic design load.)2. Feedmain BracingA,B,C,D - lateral 6

(152)1 x 40 x 31.7 x 0.5 =(1 x 12.2 x 465 x 0.5) =

634 lb(2837 N)

E-lateral 6(152)

1 x 32.5 x 31.7 x 0.5 =(1 x 9.9 x 465 x 0.5) =

515 lb(2302 N)

F-lateral 6(152)

1 x 25 x 31.7 x 0.5 =(1 x 7.6 x 465 x 0.5) =

396 lb(1767 N)

G-lateral(on feedmain)

-longitudinal(on crossmain)

6(152)

4(102)

1 x 12.5 x 31.7 x 0.5 =(1 x 3.8 x 465 x 0.5) =

1 x 60 x 16.4 x 0.5 =(1 x 18.3 x 241 x 0.5) =

==

198 lb(884 N)

492(2205)690 lb(3089 N)

(Brace G is a lateral brace for 12.5 ft [3.8 m] of feedmain, and [assuming it is located within 24 in. (0.6 m) of feedmainconnection to looped crossmain], also a longitudinal brace for 60 ft [18.3 m] of crossmain. Thus, design should be asa lateral brace for a total load of 690 lb [3089 N].)

DD,EE,FF- longitudinal

6(152)

1 x 62 x 31.7 x 0.5 =(1 x 18.9 x 465 x 0.5) =

983 lb(4394 N)

3. Crossmain BracingH,N,O,U

-lateral

-longitudinal

4(102)

11⁄2(38)

2(51)

4(102)

1 x 20 x 16.4 x 0.5 =(1 x 6.1 x 241 x 0.5) =

8 x 10 x 3.6 x 0.5 =(8 x 3.1 x 53 x 0.5) =

10 x 10 x 5.1 x 0.5 =(10 x 3.1 x 75 x 0.5) =

==

1 x 25 x 16.4 x 0.5 =(1 x 7.6 x 241 x 0.5) =Total =

=

164 lb(735 N)

144(657)

255(1163)563 lb(2555 N)

205 lb(916 N)768 lb(3471 N)



(Braces H, N, O, and U are end-of-crossmain lateral braces, located within 24 in. [0.6 m] of end of crossmain, andalso act as longitudinal braces for 25 ft [7.6 m] of the crossmain loop piping. Design should be as lateral braces withtotal crossmain and branchline load of 768 lb [3471 N].)

I,J,L,M,

P,Q,R,S,T

-lateral

4(102)

11⁄2(38)

2(51)

4 x 10 x 16.4 x 0.5 =(4 x 3.1 x 241 x 0.5) =

16 x 10 x 3.6 x 0.5 =(16 x 3.1 x 53 x 0.5) =

20 x 10 x 5.1 x 0.5 =(20 x 3.1 x 75 x 0.5) =

==

328 lb(1494 N)

288(1314)

510(2325)1126 lb(5133 N)

(These are all lateral braces with crossmain/branchline portions for total design load of 1126 lb [5133 N].)

K

-lateral

-longitudinal

4(102)

11⁄2(38)

2(51)

6(152)

4 x 10 x 16.4 x 0.5 =(4 x 3.1 x 241 x 0.5) =

16 x 10 x 3.6 x 0.5 =(16 x 3.1 x 53 x 0.5) =

20 x 10 x 5.1 x 0.5 =(20 x 3.1 x 75 x 0.5) =

==

1 x 31 x 31.7 x .5 =(1 x 9.5 x 465 x 0.5) =Total =

=

328 lb(1494 N)

288(1314)

510(2325)1126 lb(5133 N)

491 lb(2209 N)1617 lb(7342 N)

(Brace K is a lateral brace for the crossmain as well as a longitudinal brace for 31 ft [9.5 m] of the feedmain, andshould be designed as a lateral brace with a total load of 1617 lb [7842 N].)

V,Y,Z,CC-lateral

-longitudinal

4(102)

4(102)

1 x 16.5 x 16.4 x 0.5 =(1 x 5.0 x 241 x 0.5) =

1 x 40 x 16.4 x 0.5 =(1 x 12.2 x 241 x 0.5 =Total =

=

135 lb(603 N)

328 lb(1740 N)

463 lb(2073 N)

(Braces V, Y, Z and CC are end-of-crossmain lateral braces, located within 24 in. (0.6 m) of end of crossmain, andalso act as longitudinal braces for 40 ft (12.2 m) of the crossmain loop piping. Design should be as lateral braces withtotal load of 463 lb (2073 N).)

W,X,AA,BB-lateral

4(102)

1 x 33 x 16.4 x 0.5 =(1 x 10.1 x 241 x 0.5) =

271 lb(1217 N)

GG,HH-longitudinal

4(102)

1 x 60 x 16.4 x 0.5 =(1 x 18.3 x 241 x 0.5) =

492 lb(2205 N)

II,JJ-longitudinal

4(102)

1 x 50 x 16.4 x 0.5 =(1 x 15.3 x 241 x 0.5) =

410 lb(1844 N)

KK,LL-longitudinal

4(102)

1 x 80 x 16.4 x 0.5 =(1 x 24.4 x 241 x 0.5) =

656 lb(2940 N)



3.9.4 Tree System No. 3

Step 1. Layout and orientation of braces. Fig. 3.9.4.1 shows the layout for the two-way lateral braces, anda four-way brace at the riser. Fig. 3.9.4.2 show the layout of the two-way longitudinal braces. Dashed lines indi-cate the portions of the piping system (zone of influence) to be calculated for each brace.

Step 2. Calculate design load requirements. Using a 0.5 G factor, and Schedule 40 pipe, horizontal seismicdesign loads on each brace will be as shown in Table 3.9.4.

Step 3. Select the proper brace type, size and maximum length. Based on the configuration of the brace con-nection to the structure, the angle of the brace from the vertical, and the calculated horizontal design load,the brace type, size and maximum length can be selected from Table 3.2.1(b).

Step 4. Using the Step 2 design loads, and the brace angle from the vertical, select the appropriate typeand size of fastener for attachment to the building structure.

Steps 3 and 4. Use same approach as in 3.9.2.

Fig. 3.9.4.1. Layout and zones of influence for lateral and four-way sway bracing for System #3.



Fig. 3.9.4.2. Layout and zones of influence for longitudinal and four-way sway bracing for System #3.



Table 3.9.4. Horizontal Seismic Design Loads for System No. 3



Force, lb (N)

1. Riser Bracing (RB)Lateral

Longitudinal

8(203)

8(203)

8(203)

8

1 x 30 x 47.7 x 0.5 =(1 x 9.2 x 700 x 0.5) =

1 x 12.5 x 47.7 x 0.5 =(1 x 3.8 x 700 x 0.5) =

==

1 x 30 x 47.7 x 0.5 =(1 x 9.2 x 700 x 9.5) =

1 x 25 x 47.7 x 0.5 =(1 x 7.6 x 700 x 0.5) =

==

716 lb(3220 N)

298(1330)1014 lb(4550 N)

716 lb(3220 N)

596(2660)1312 lb(5880 N)

(The riser bracing will need to be designed to withstand simultaneously a 1014 lb (4550 N) lateral and 1670 lb (5880N) longitudinal horizontal seismic load.)

2. Feedmain BracingM,N,-lateral

6(152)

1 x 33 x 31.7 x 0.5 =(1 x 10 x 465 x 0.5) =

523 lb(2325 N)

(Braces M and N pick up the lateral load for 33 ft (10 m) of feedmain piping. Four-way braces T and Q will pick up the16.5 ft (5 m) of piping north of Brace M and south of Brace N, respectively.)

O-lateral

6(152)

1 x 25 x 47.7 x 0.5 =(1 x 7.6 x 700 x 0.5) =

596 lb(2660 N)

V-longitudinal

6(152)

1 x 50 x 31.7 x 0.5 =(1 x 15 x 465 x 0.5) =

793 lb(3488 N)

3. Four-way Feedmain/Crossmain BracingQEast-to-West Portionlateral

longitudinal

8(203)

6(152)

6(152)

4(102)

1 x 12.5 x 47.7 x 0.5 =(1 x 3.8 x 700 x 0.5) =

1 x 16.5 x 31.7 x 0.5 =(1 x 5.0 x 465 x 0.5) =

3 x 10 x 31.7 x 0.5 =(3 x 3.1 x 465 x 0.5) =

4 x 10 x 16.4 x 0.5 =(4 x 3.1 x 241 x 0.5) =East-to-West Toal Load =

=

298 lb(1330 N)

262(1163)

476(2162)

328(1494)1364 lb(6149 N)



North-to-South Portionlateral

1(25)

11⁄4(32)

1½(38)

6(152)

8(203)

6(152)

8 x 10 x 2.1 x 0.5 =(8 x 3.1 x 31 x 0.5) =

4 x 10 x 2.9 x 0.5 =(4 x 3.1 x 43 x 0.5) =

6 x 10 x 3.6 x 0.5 =(6 x 3.1 x 53 x 0.5) =

1 x 10 x 31.7 x 0.5 =(1 x 3.1 x 465 x 0.5) =

1 x 12.5 x 47.7 x 0.5 =(1 x 3.8 x 700 x 0.5) =

1 x 16.5 x 31.7 x 0.5 =(1 x 5.0 x 465 x 0.5) =North-to-South Total Load =

=

84 lb(384 N)

58(267)

108(493)

159(721)

303(1330)

262(1163)974 lb(4358 N)

(Brace Q needs a design to withstand simultaneously a 1364 lb (6149 N) load in the east-west direction and 974 lb(4358 N) load in the north-south direction. Alternatively, two separate sway braces may be used, and should belocated within 24 in. (0.5 m) of the tee.)

T-East-to-West Portionlateral

longitudinal

North-to-South Portionlateral

6(152)

6(152)

4(102)

1(25)

11⁄4(32)

1½(38)

6(152)

6(152)

1 x 16.5 x 31.7 x 0.5 =(1 x 5.0 x 465 x 0.5) =

3 x 10 x 31.7 x 0.5 =(3 x 3.1 x 465 x 0.5) =

4 x 10 x 16.4 x 0.5 =(4 x 3.1 x 241 x 0.5) =East-to-West Total Load =

=

8 x 10 x 2.1 x 0.5 =(8 x 3.1 x 31 x 0.5) =

4 x 10 x 2.9 x 0.5 =4 x 3.1 x 43 x 0.5) =

6 x 10 x 3.6 x 0.5 =(6 x 3.1 x 53 x 0.5) =

1 x 10 x 31.7 x 0.5 =(1 x 3.1 x 465 x 0.5) =

1 x 16.5 x 31.7 x 0.5 =(1 x 5.0 x 465 x 0.5) =North-to-South Total Load =

=

262 lb(1163 N)

476(2162 N)

328(1494)1066 lb(4819 N)

84 lb(384 N)

58(267)

108(493)

159(721)

262(1163)671 lb(3028 N)

(Brace T needs to be designed to withstand simultaneously a 1066 lb (4819 N) load in the east-west direction and a671 lb (3028 N) load in the north-south direction. Alternatively, two separate sway braces may be used and should belocated within 24 in. (0.6 m) of the tee.)



4. Crossmain BracingA,F,G,L-lateral

1(25)

11⁄4(32)

1½(38)

2(51)

2½(64)

3(76)

12 x 10 x 2.1 x 0.5 =(12 x 3.1 x 31 x 0.5) =

6 x 10 x 2.9 x 0.5 =(6 x 3.1 x 43 x 0.5) =

9 x 10 x 3.6 x 0.5 =(0 x 3.1 x 53 x 0.5) =

1 x 10 x 5.1 x 0.5 =(1 x 3.1 x 75 x 0.5) =

1 x 10 x 7.9 x 0.5 =(1 x 3.1 x 116 x 0.5) =

1 x 10 x 10.8 x 0.5 =(1 x 3.1 x 159 x 0.5) =

==

126 lb(577 N)

87(400)

162(739)

26(116)

40(180)

54(246)495 lb(2258 N)

(Braces A, F, G, and L are end-of-crossmain braces located within 24 in. [0.6 m] of end of crossmain, with crossmain/branchline portions for a total design load of 495 lb [2258 N].)B,E,H,K -lateral

1(25)

11⁄4(32)

1½(38)

3(76)

4(102)

16 x 10 x 2.1 x 0.5 =(16 x 3.1 x 31 x 0.5) =

8 x 10 x 2.9 x 0.5 =(8 x 3.1 x 43 x 0.5) =

12 x 10 x 3.6 x 0.5 =(12 x 3.1 x 53 x 0.5) =

1 x 10 x 10.8 x 0.5 =(1 x 3.1 x 159 x 0.5) =

3 x 10 x 16.4 x 0.5 =(3 x 3.1 x 241 x 0.5) =

==

168 lb(769 N)

116(533)

216(986)

54(246)

246(1121)800 lb(3655 N)

C,D,I,J-lateral

125

11⁄4(327)

1½(38)

4(102)

6(152)

16 x 10 x 2.1 x 0.5 =(16 x 3.1 x 31 x 0.5) =

10 x 10 x 2.9 x 0.5 =(10 x 3.1 x 43 x 0.5) =

15 x 10 x 3.6 x 0.5 =(15 x 3.1 x 53 x 0.5) =

3 x 10 x 16.4 x 0.5 =(3 x 3.1 x 241 x 0.5 =

1 x 10 x 31.7 x 0.5 =(1 x 3.1 x 465 x 0.5) =

==

168 lb(769 N)

145(667)

270(1232)

246(1121)

160(721)1031 lb(4678 N)



P,R,S,U- longitudinal

2(51)

2½(64)

3(76)

4(102)

1 x 10 x 5.1 x 0.5 =(1 x 3.1 x 75 x 0.5) =

1 x 10 x 7.9 x 0.5 =(1 x 3.1 x 116 x 0.5) =

2 x 10 x 10.8 x 0.5 =(2 x 3.1 x 159 x 0.5) =

4 x 10 x 16.4 x 0.5 =(4 x 3.1 x 241 x 0.5) =

==

26 lb(116 N)

40(180)

108(493)

328(1494)502 lb(2283 N)

FM Engr. Comm. December 1998



Documents

Earthquake Protection for Fire Systems