Fire Sprinkler Earthquake Protection – Sway Bracing

Abstract

• Earthquake sway bracing for fire sprinklers will become normative in the EN12845 Annex

• Building structures are protected against earthquakes and so should the life safety system of fire sprinklers

Abstract

• Fire sprinkler protection provided thru:– Joint flexibility– Proper clearances– Sway Bracing

• Sway bracing consists of:– Lateral– Longitudinal– 4Way

Abstract

• Brace design is based on the amount of sprinkler pipe weight within a zone of influence (ZOI) for a given horizontal seismic load (“g” force)– Requires calculations and submittals to

AHJ’s showing brace meets design loads

Abstract

• Brace assembly strength is limited to the load capacity of the weakest component– Requires 3rd party load testing & certification

Today’s Presentation

• Importance of bracing fire sprinklers

• Brace assembly components

• General rules for brace placement

Importance of Bracing

Fire Sprinklers

FM Global - Understanding the Hazard

“Lack of Earthquake Bracing on Sprinkler System”

10 Year Period (FM Global)

• 561 earthquakes worldwide

• $315 million (USD) in damages facilities

• $560,000 (USD) average loss

• 50% of average loss is due to sprinkler system failure

How Damage Occurs

• Building movement is different than the fire sprinkler pipe

• Unbraced fire sprinklers damage may occur by:– Hitting walls, suspended ceilings or other

building systems– Fittings break due to twisting– Couplings can separate or leak during

excessive bending, rotation or movement

Additional Concerns

• Protecting against loss from fire or water leakage is a critical towards recovery from an earthquake

• Time for water leak discharge to fill a 14 ft x 14 ft (4.3m x 4.3m) room to depth of 1 foot (30cm) based on 50 psi (3.4 bar):

Time(in) (mm) (minutes)1/2 12 37

1 32 8.11 1/2 40 4.0

2 50 2.74 100 1.56 150 1.3

Pipe Diameter

Ways to Avoid Sprinkler Damage

• Bracing

• Flexibility

• Clearance

• Other Considerations– Brace suspended ceilings– Weak brace and/or hanger attachments– Anchoring of equipment, tanks & racks

Costs to Brace

• 3 – 4% if installed with the sprinkler system

• Retrofit costs vary widely from an estimated $100 - $500 USD per brace location

Importance of Sprinkler Bracing - Summary

• Critical after earthquake protection against:– Water leaks– Fires

• Decreases loss of:– Property– Function / use of facilities

• Increases life safety

Brace Assembly Components

Sway Brace Components

Brace Clamp

Structure Attachment

Brace

Structural Attachments

CSBUNIV – Universal Structural

Structural Attachments

CSBBARJ – I-Beam Attachment

Structural Attachments

CSBIB – Adjustable I-Beam Attachment

Structural Attachments

CSBMA – Multi Attachment

Brace Clamps – Lateral Only

CSBQIKCL – Quick Grip Jr

CSBQG – Quick Grip

Brace Clamps – Lateral & Longitudinal

CSBEZU and CSBSTU Universal Brace Clamp

General Rules

For

Brace Placement

Lateral Bracing

Lateral Bracing

• What:– Feed and cross mains (any size)– Branch and other piping > 2 ½” (65mm)

diameter

• Where:– 40 ft o.c. (12m) maximum spacing– On the last length of pipe at the end of a main– Within 6 ft (1.8m) of the end of the pipe

Lateral Bracing

Lateral Bracing

• Can act as longitudinal brace if installed within 2 ft (0.6m) of piping braced longitudinally

Note that Pipe A Diameter > Pipe B Diameter

Longitudinal Bracing

Longitudinal Bracing

• What:– Feed and cross mains (any size)– Branches > 2 ½” (65mm) diameter

• NFPA 13 Not Required• FM DS 2-8 Required if longer than 40 ft (12.2m)

• Where:– 80 ft (24.2m) o.c. maximum spacing– Within 40 ft (12.2m) of the end of the pipe or

change in direction

Longitudinal Bracing

Longitudinal Bracing

• Can act as a lateral brace if installed within 2 ft (0.6m) of piping braced laterally

Riser Bracing

• Riser tops exceeding 3 ft (0.9m) in length

• Maximum Spacing = 25 ft (7.6m) o.c.

Thank You

Any Questions??