Forward flow testing of RP's on Glycol Loops

[ContractorDave]

I may have asked this question before ... I know that NFPA hasn't replied to me on this yet: Is forward flow testing required on the glycol RP?

Dave

 

[Cidona]

An area of grey would seem to be 'at maximum flow rate posible'. Under what conditions? How do you size the header pipe. Same size as the valve? Run as long as you want?
Just to through it out there as food for thought,and I haven't dealt with AF systems in a while, but might it be an option on some of these buildings with alot of AF systems, to swap out the big DDCA at the supply for a RPZ and change the existing small AF RPZs for swing checks with 3/32 orifice. The cost might be offset in certain cases with not needing to retro fit multiple test headers and reduce testing costs in the future. Obviously actual valve takeouts and availability need to be verified.

 

[ContractorDave]

That's actually a pretty darn good idea Cidona. I'll at least recommend this for future installs!

Regards
Dave

 

[Cidona]

Hope it helps Dave (or you find a better way).
Just to mention as a reminder, RPZs typically have more friction loss, so that needs to be concidered. Though hopefully with the improved hydraulic design of the newer models, along with the reduced takeouts, may still remain an option for these new buildings.
Accomadation for RPZ discharge would also have to be concidered, etc.
100 buildings! Nice work if you can get it. Good luck!