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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??