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Can you use a reduced pressure principal backflow preventer?

jar546

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Does the 2021 IPC Section 608.17.6 require a reduced pressure principle backflow preventer to protect the potable water supply from an automatic sprinkler system without chemical additives or antifreeze when the sprinkler system is equipped with a fire department connection?

This is my report on the ICC's opinion:

Under Section 608.17.4 of the 2021 IPC, either a double check-valve backflow prevention assembly or a reduced pressure principal backflow preventer is authorized to safeguard the potable water system from possible pollution through the automatic sprinkler system's piping. This section mandates backflow protection where the potable water supply links to an automated fire sprinkler system that includes a fire department connection. Meanwhile, Section 608.17.6 establishes fundamental standards for general applications not primarily addressed by the code.

Section 608.17.6's broad guidelines are designed to supplement but not replace the more specific directives of Section 608.17.4, which allow a double check-valve backflow prevention assembly as the basic level of backflow protection required for automatic sprinkler systems. This necessity arises particularly when a fire department's connection during firefighting activities may raise the system's pressure above that of the domestic water supply, creating a "backpressure" scenario.

The double check-valve backflow prevention assembly, suitable for backpressure situations typically encountered in automatic sprinkler systems, meets the criteria of Section 608.14.7. Per Table 608.1, double check-valve assemblies are approved solely for use in low-hazard conditions involving backpressure or back-siphonage. In instances where the pressure within the contaminated segment temporarily exceeds that of the potable water system, the double check-valve backflow preventer is crucial to prevent contamination.

It's important to recognize that double-check valve assemblies are certified only for low-hazard conditions where the potential contaminants may affect the water's aesthetic quality but pose no significant health risks. Conversely, a reduced-pressure principal backflow preventer is necessary for separating high-hazard applications—such as automatic sprinkler systems that might use nonpotable external water sources or contain additives like chemicals or antifreeze—from the potable water supply. Code officials and system designers must evaluate all possible external water sources that could be connected through the fire department connection to assess the contamination risk thoroughly before selecting the appropriate backflow prevention device.
 
Does the 2021 IPC Section 608.17.6 require a reduced pressure principle backflow preventer to protect the potable water supply from an automatic sprinkler system without chemical additives or antifreeze when the sprinkler system is equipped with a fire department connection?

This is my report on the ICC's opinion:

Under Section 608.17.4 of the 2021 IPC, either a double check-valve backflow prevention assembly or a reduced pressure principal backflow preventer is authorized to safeguard the potable water system from possible pollution through the automatic sprinkler system's piping. This section mandates backflow protection where the potable water supply links to an automated fire sprinkler system that includes a fire department connection. Meanwhile, Section 608.17.6 establishes fundamental standards for general applications not primarily addressed by the code.

Section 608.17.6's broad guidelines are designed to supplement but not replace the more specific directives of Section 608.17.4, which allow a double check-valve backflow prevention assembly as the basic level of backflow protection required for automatic sprinkler systems. This necessity arises particularly when a fire department's connection during firefighting activities may raise the system's pressure above that of the domestic water supply, creating a "backpressure" scenario.

The double check-valve backflow prevention assembly, suitable for backpressure situations typically encountered in automatic sprinkler systems, meets the criteria of Section 608.14.7. Per Table 608.1, double check-valve assemblies are approved solely for use in low-hazard conditions involving backpressure or back-siphonage. In instances where the pressure within the contaminated segment temporarily exceeds that of the potable water system, the double check-valve backflow preventer is crucial to prevent contamination.

It's important to recognize that double-check valve assemblies are certified only for low-hazard conditions where the potential contaminants may affect the water's aesthetic quality but pose no significant health risks. Conversely, a reduced-pressure principal backflow preventer is necessary for separating high-hazard applications—such as automatic sprinkler systems that might use nonpotable external water sources or contain additives like chemicals or antifreeze—from the potable water supply. Code officials and system designers must evaluate all possible external water sources that could be connected through the fire department connection to assess the contamination risk thoroughly before selecting the appropriate backflow prevention device.
the last sentence would dictate the requirement, would it not? if non potable external water source is used by fire department. When system is not under constant pressure an air gap or atmospheric vacuum breaker can be used. 608.17.4.1
 

608.14.7 Double check backflow prevention assemblies.

Double check backflow prevention assemblies shall conform to ASSE 1015, CSA B64.5, CSA B64.5.1 or AWWA C510. Double check detector fire protection backflow prevention assemblies shall conform to ASSE 1048. These assemblies shall be capable of operating under continuous pressure conditions.

The Table is a little bit misleading since the first row does not mention ASSE 1048 as being required for fire protection systems.

TABLE 608.1

APPLICATION OF BACKFLOW PREVENTERS

DEVICE​
DEGREE OF HAZARDa​
APPLICATIONb​
APPLICABLE STANDARDS​
Backflow prevention assemblies:​
Double check backflow prevention assembly and double check fire protection backflow prevention assembly
Low hazard​
Backpressure or backsiphonage Sizes 3/8˝–16˝​
Double check detector fire protection backflow prevention assemblies​
Low hazard​
Backpressure or backsiphonage Sizes 2˝–16˝​
 
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