Backflow Preventer Test

[carlosgw]

Is the backflow preventer in NFPA 13 24.2.5 any backflow preventer or does it refer to a specific device (it say "the")?
E.G. Does the check valve/double check/RPZ at the service required a full demand forward test (and consequently a means to accomplish it)?
Is it required for NFPA 13R systems? (it is not mentioned in NFPA 13R)

 

[LCREP]

Yes on the valves you indicated as per 13& 25, if you have a backflow device you need to provide the means to flow test. NFPA 25 requires the test. I do not have 13R so I can not comment. I would think it applies since NFPA 25 covers 13R.

The following is from the NFPA 25 Handbook 2011 Ed.

13.6.2.1* All backflow preventers installed in fire protection system piping shall be tested annually by conducting a forward flow test of the system at the designed flow rate, including hose stream demand, where hydrants or inside hose stations are located downstream of the backflow preventer.

A.13.6.2.1 The full flow test of the backflow prevention valve can be performed with a test header or other connections downstream of the valve. A bypass around the check valve in the fire department connection line with a control valve in the normally closed position can be an acceptable arrangement. When flow to a visible drain cannot be accomplished, closed loop flow can be acceptable if a flowmeter or sight glass is incorporated into the system to ensure flow.
The tests required by 13.6.2 typically test only for operation of the device under backflow conditions. Forward-flow test conditions are required by other portions of this standard.

The 2010 edition of the standard requires only a forward flow test of the system through the backflow preventer. The backflow test was deemed by the technical committee to be outside the scope of the standard, because it is a requirement of water quality standards and performed by an individual with specific training and license to do so. However, many contractors have obtained the required licenses to perform the backflow test and do so as part of their service offering.

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[cdafd]

If not 13r may be a state, city or other agency requirement to test any type of backflow


My understanding is not all types of back flows are testable

 

[Sdpaddler50]

Personally, i think we have gone a little back flow crazy in the past 20 years. Some ahjs are requiring double detector checks to be changed out with a reduced pressure system, thus greatly increasing the friction loss, and affecting the sprinkler hydraulics. Ie, they are having these installed w/o an engineering study. Secondly, i have read different opinions indicating a well serviced check valve arrangement can be just as effective as the reduced pressure type. But, i am no expert in this field so others can enlighten me if you disagree.

Thirs point, in regards to this post, i am in CA, and i dont believe the guys that test these do the full flow test as noted very often. When i see them test, they have some gages set up looking at differential pressures across the back flow assembly and some other basic checks. Seems a bit like a racket to me where they are charging good money for an hours worth of work. Curious what others are noting, especially in CA.

 

[cdafd]

Currently only seeing the gage test, but it seems to do the job. Have seen reports of failures

But I believe these are two tests 1. Is the backflow working test, 2. The forward flow test.

 

[LCREP]

Check this link out nice overview from NFSA on how to pipe the device for testing.
Link

****************************************
Fire Sprinklers Save Firefighters’ Lives Too!
Interested in “Hands On” Fire Protection Seminars with live fires visit

http://www.chubb.com/lcu

for information.