simplest permanent means to allow a BFP forward flow test

[pipesnpumps]

I am seeking input from you guys on the simplest setup that allows for permanent testing for a backflow preventor at full system demand flow.. while the flow is measured.

The components for attaching to the system and flow testing should be available to standard fire service personnel otherwise it will never get done.

The cadillac approach is obviously the same setup as an NFPA 20 pump flow test header.

A minimalist approach was suggested by SD2 in another thread (reposted below), but I am not sure how the flow could be measured with this setup..

Any other ideas?

QUOTE: " SprinklerDesigner2 (Mechanical) 1 Jun 10 16:10
The easiest way to comply with forward testing of BFP's would be to add a grooved weld outlet, 4" butterfly and pipe down as if it were a main drain.

On systems having higher demands, such as .60/2000, you could replace the 4" with 6".

Valve is normally closed, and does not control sprinkler water, so tamper is not required.

$250 for butterfly valve
$20 for weld
$10 for 4" 45 deg elbow
$20 for two 4" 90 deg elbows
$20 for pipe
$60 for couplings

Less than $300 would do it. "
/END QUOTE

 

[TravisMack]

With the description below, you know the diameter of the outlet. You would measure flow with a pitot, just like you would for a hydrant flow test.

Travis Mack
MFP Design, LLC

http://www.mfpdesign.com

 

[pipesnpumps]

but in nearly every case, it would require some way to direct the water, right?

What about SD2s suggestion, but with a siamese test connection for hooking up hoses to play pipes or hose monsters? that would work, but it would not be controllable to test at the exact design flow, unless the fire service threaded valves in line.. Is that practical for them to do? I don't know, I was hoping some of you might.

I suppose there could be no valve(s) other than the gate/BF control valve, but the flow would run wild, and that would defeat the purpose of the test, because it would not have repeatable results to compare to the last test..

 

[chevy4x4trucks]

Our inpsectors have test header pieces that they couple on after the butterfly valve that have hose connections on them so they can measure flow the same way they would during a pump test. It only costs a few bucks to make up a piece of 4" pipe with a few 2-1/2" outlets that you can take from job to job with you for the inspections.

 

[cdafd]

suggest you do use a rope tamper on the normaly closed valve, so in case some one does open it someone knows

and your set up is what I normaly see, luckily they have been directly outside, and onto paved area where no damage can result

I like the idea of 2 1/2 if needed to direct water away