Water Pipe Sizing

Introduction to Water Pipe SizingUnderstanding the Many

Methods to Size Water Pipe

ONTARIO PLUMBING INSPECTORS ASSOCIATION INC.In the public service since 1920

OPIA Education and Training

Presented by:Rainier Bratsch-Blundel, CPSIPlumbing Professor – George Brown College

1

Introduction to Water Pipe Sizing

Where to start. ASPE Data Books

2006 Building Code

National Plumbing Code of Canada

OPIA Education and Training 2


What is found in the ASPE Data Books?1. A list of empirical formulae for piping friction

losses including; The Hazen-Williams Formula

city mains and fire mains

The Darcy-Weisbach Formula plumbing and process piping – friction factor is determine

by the Colebrook equation



What is found in the ASPE Data Books?2. A method formula for probability of use. Uses a series of tables assigning Water Size Fixture

Units to the most common found fixtures in a plumbing system.

This is the method found in the Body of the Codes and Appendices of the National Plumbing Code of Canada and Ontario Plumbing Code and Guide.



Where to look in the Building Code?7.6.1.1. Design, Fabrication and Installation(1) Potable water systems shall be designed, fabricated and

installed in accordance with good engineering practice, such as that described in the ASHRAE Guide and Data Books, the ASHRAE Handbooks and ASPE Data Books.

(ASHRAE: American Society of Heating, Refrigerating and Air-Conditioning Engineers, last update 1972),

(ASPE: American Society of Plumbing Engineers, updated 2005)



More from the Building Code?7.6.3.1. Design(1) Except as permitted in Sentences (2) and (3), the size of

every pipe in a water distribution system that supplies water to a fixture or device and the flow pressures at the supply openings shall be designed to provide peak demand flow in conformance to Table 7.6.3.1.

(2) A tail piece or connector not more than 750 mm long and not less than ¼ in. inside diameter may be used to supply water to a fixture or device.

Cont.OPIA Education and Training 6


More from the Building Code?7.6.3.1. Design (cont.)(3) A water distribution system that serves not more than a

single dwelling unit does not need to conform to Column 3 of Table 7.6.3.1.

(4) No water system between the point of connection with the water service pipe or the water meter and the first branch that supplies a water heater, shall be less than ¾ in. size.

(5) Every pipe that supplies a fixture shall have a capacity that will produce a flow in the fixture that will flush the fixture and keep it in a sanitary condition.



Where to look in the Building Code?7.6.3.2. Hydraulic Load(1) Except as provided in Sentence (3), the hydraulic load of a

fixture or device that is listed in Table 7.6.3.1. shall be the number of fixture units given in the Table.

(3) Where fixtures are supplied with both hot and cold water, the hydraulic loads for maximum separate demands shall be 75% of the hydraulic load of the fixture units given in Tables 7.6.3.1. and 7.6.3.2. when using a detailed engineering design method.



T-7.6.3.1.

T-7.6.3.2.



What's in the Appendix of the Building Code? The following may be used as an alternative in determining

the size of each section of the water system. This is based on proven design methods found in the Appendix of the National Plumbing Code of Canada.

To determine the size of each section of the water supply and distribution systems, use Table A-7.6.1.1.(1), which incorporates the requirements of Sentence 7.6.2.3.(3) for sizing the Water Service Entering the Building.



STEP 1: Determining conditionsOn a proposed water piping installation sized pursuant to Table

A-7.6.1.1.(1), the following conditions need to be determined:

i. the total number of "Water Supply Fixture Units" as determined from Tables 7.6.3.1. and 7.6.3.2. for the fixtures to be installed,

ii. the developed length of the pipe from the property line to the most remote outlet, or if the pressure at the property line or meter is unknown, the developed length from the public water main to the most remote outlet,



STEP 1: Determining conditionsOn a proposed water piping installation sized pursuant to Table

A-7.6.1.1.(1), the following conditions need to be determined:

i. the total number of "Water Supply Fixture Units" as determined from Tables 7.6.3.1. and 7.6.3.2. for the fixtures to be installed,

ii. the developed length of the pipe from the property line to the most remote outlet, or if the pressure at the property line or meter is unknown, the developed length from the public water main to the most remote outlet,



STEP 1: Determining conditions (cont.)

iii. the difference in elevation between the water piping at the property line or other source of supply and the highest fixture or outlet,

iv. the pressure in the public water main or other source of supply at the locality where the installation is to be made (this pressure may need to be reduced so that the pressure in the water distribution system does not exceed 550 kPa); and,



STEP 1: Determining conditions (cont.)

v. finally, in localities where there is a wide fluctuation of pressure in the main throughout the day, determine the minimum pressure available, which will be used as a basis for this design.



STEP 2: Water Service Pipe

i. Beginning with the available pressure at the property line, public water main or other souceof supply, and subtracting 10 kPa for each metre of difference in elevation between such source of supply and the highest water outlet in the building or on the premises, use the "Pressure Range" group in Table A-7.2.6.1.(1) within which the adjusted pressure falls.




ii. Select the "Length Column" that is equal to or longer than the required length of service pipe. Follow down the column to a "Water Supply Fixture Unit" equal to or greater than the total number of units required by the installation. Having located the proper unit value for the required length, locate the size of the water service in the left-hand column.



STEP 2: Table A-7.6.1.1.(1) 200kPa to 310kPa



STEP 2: Table A-7.6.1.1.(1) 311kPa to 413kPa



STEP 2: Table A-7.6.1.1.(1) Over 413kPa



STEP 3: Cold Water PipingStarting at the most remote outlet on the cold water piping and working back toward the water service or meter, using the total developed length of pipe, calculate the pipe size for the system using the total "Water Supply Fixture Unit" values given in Tables 7.6.3.1 and 7.6.3.2. and adding the unit demand of the hot water inlet at the point where it occurs. The final size of the cold water service need not be larger than the size required by Table A-2.6.1.1.(1) for the water service.



STEP 4: Hot Water PipingStarting at the most remote outlet on the hot water piping and working back toward the service water heater, calculate the pipe sizing for the system from the "Length Column" selected in Table A-7.6.1.1.(1) using the "Water Supply Fixture Unit" valves given in Table 7.6.3.1. and 7.6.3.2.



Example OBC:


BathLav

WCHoseBibb

KS DW Cl. W.HWT

Bath

Cl. W.

WCLav

BathLav

WCSHR

LavWC

KSDW Hose

Bibb


T-7.6.3.1.

T-7.6.3.2.



(i) the total number of "Water Supply Fixture Units"


FIXTURE 7.6.3.1. 75% W.S.F.U FIXTURESW.S.F.U.

COLD HOT

W.C. 3 NA 3 4 12 -

LAV 1 .75 .75 4 3 3

BATH 2 .75 1.5 3 4.5 4.5

SHR 2 .75 1.5 1 1.5 1.5

K.S. 2 .75 1.5 2 3 3

D.W. 3 NA 3 2 - 6

CL.W. 3 .75 2.25 2 4.5 4.5

H.B. 4 NA 4 2 8 -

TOTAL COLD 59 SUB-TOTAL 36.5 22.5


(ii) – (iv) Determining Conditions


(ii) - (iv) DETERMINE CONDITIONS

DEVELOPED LENGTH 23 m

PRESSURE AT SOURCE 550 kPa

CHANGE IN ELEVATION 9 m

MINUS 10kPa PER metre - 90 kPa

PRESSURE RANGE 460 kPa


STEP 2: Table A-7.6.1.1.(1) Over 413kPa





SIZING as per A-7.6.1.1.(1)

WATER SERVICE 1” (1 1/4“)

WATER DISTRIBUTION

PIPING

1” 55 WSFU

3/4” 24 WSFU

1/2" 7 WSFU

1 1/4” 108 WSFU


Example OBC: STEP 3: Cold Water Piping


BathLav

WCHoseBibb

KS DW Cl. W.HWT

Bath

Cl. W.

WCLav

BathLav

WCSHR

LavWC

KSDW Hose

Bibb1/2"1/2"

3/4"1/2"

3/4"1/2"

3/4"3/4" 1/2“

3/4"1"

1 1/4"1 1/4"

3/4"

1/2"

1/2"1/2“1/2"

1"

1 1/4“


Example OBC: STEP 4: Hot Water Piping


BathLav

WCHoseBibb

KS DW Cl. W.HWT

Bath

Cl. W

WCLav

BathLav

WCSHR

LavWC

KSDW Hose

Bibb1/2"1/2"3/4"

1/2"3/4"

1/2"

3/4"3/4"

3/4"

3/4"

1/2"

1/2"3/4"


Changes to the National Plumbing Code (NPC);2.6.3.1. Design(1) Every water distribution system shall be designed

to provide peak demand flow when the flow pressures at the supply openings conform to Table 2.6.3.1. the plumbing supply fitting manufacturer’s specifications.



Changes to the National Plumbing Code;2.6.3.4. Size(5) Where both hot and cold water is supplied to fixtures in residential

buildings containing one or two dwelling units or row houses with separate water service pipes, the water system may be sized in accordance with Table 2.6.3.4. where:

(a) the hydraulic loads for maximum separate demands on water distribution system piping are not less than 100% of the hydraulic load of the fixture units given in Table 2.6.3.1. or 2.6.3.2. for private use,

(b) the minimum water pressure at the entry to the building is 200 kPa, and

(c) the total maximum length of water system is 90 m.OPIA Education and Training 31



Addition of Table 2.6.3.1. to the NPC;


Table 2.6.3.4.Water Pipe Sizing for Buildings Containing One or Two Dwelling Units or

Row Houses with Separate Water Service PipesForming Part of Sentence 2.6.3.4.(5)

Note to Table 2.6.3.4.:(1) Table 2.6.3.4. is not intended to limit water velocities that are specified in Sentence 2.6.3.5.(1)-2010.


Size of Water Pipe,

inches

Water Velocity, m/s(1)

3.0 2.4 1.5

Hydraulic Load, fixture units

½ 8 7 4¾ 21 16 91 43 31 18

1 ¼ 83 57 30


Changes to the National Plumbing Code;

2.6.3.5. Velocity(1) The maximum permitted flow velocities shall be

those recommended by the pipe and fitting manufacturer.



Example NPC:


BathLav

WCHoseBibb

KS DW Cl. W.HWT

Bath

Cl. W.

WCLav

BathLav

WCSHR

LavWC

KSDW Hose

Bibb


(i) the total number of "Water Supply Fixture Units"


FIXTURE 7.6.3.1.H/C

TOTALFIXTURESW.S.F.U.

COLD HOT

W.C. 2.2 8.84 8.8 -

LAV 0.5 2.84 2 2

BATH 1 4.23 3 3

SHR 1 1.41 1 1

K.S. 1 2.82 2 2

D.W. 1.4 2.82 - 2.8

CL.W. 1 2.82 2 2

H.B. 2.5 52 5 -

TOTAL COLD 30.6 SUB-TOTAL 23.8 12.8

H/C

2.2

0.7

1.4

1.4

1.4

1.4

1.4

2.5


Example NPC: Cold Water Piping


BathLav

WCHoseBibb

KS DW Cl. W.HWT

Bath

Cl. W.

WCLav

BathLav

WCSHR

LavWC

KSDW Hose

Bibb1/2"1/2"

3/4"1/2"

1/2“3/4"

3/4"1 "

1"3/4"

1/2"

1/2“1/2"

1"

1“


Example NPC: Hot Water Piping


BathLav

WCHoseBibb

KS DW Cl. W.HWT

Bath

Cl. W

WCLav

BathLav

WCSHR

LavWC

KSDW Hose

Bibb1/2"1/2"1/2"

1/2"3/4"

1/2"

3/4"

3/4"

1/2"

1/2"3/4"


QUESTIONS? www.opia.info/members/

http://www.georgebrown.ca/apprenticeship/seminar_backflow.aspx

[email protected]

http://nationalcodes.ca/eng/public_review/2008/proposed_changes.shtml


Introduction to Water Pipe SizingUnderstanding the Many

Methods to Size Water Pipe

ONTARIO PLUMBING INSPECTORS ASSOCIATION INC.In the public service since 1920

OPIA Education and Training

Presented by:Rainier Bratsch-Blundel, CPSIPlumbing Professor – George Brown College

40

Documents

Water Pipe Sizing