Hey all,
As I am not so familiar with NFPA designs, currently we designed a wet automatic sprinkler pipe system to run on a separate fire pump from another deluge sprinkler system, which will have another separate fire pump.
But does NFPA allow both separate sprinkler systems, wet automatic +...
Dear all,
Has anyone had experience designing for water spray systems that go beyond 5000 GPM in capacity? e.g 9000 GPM
We need to know how we should size the pipes, as according to the minimum pize sizing table in NFPA20, it only shows up to 5000 GPM rating...
However, let's say we have a...
hi UFT12, the system design pressure is set at 175 PSI. The churn pressure is always higher than system pressure.
But because we are basing on a formula given by NFPA 20 Annex A, whereby the jockey pump cutout setting shall be anything at churn pressure, we feel that this sort of information is...
Dear all,
As we are complying to NFPA standards as close as possible, one of the confusion starts is with NFPA 20 2019 Annex A A.14.2.6 (4):
Fire Pump Settings. The fire pump system, when started by
pressure drop, should be arranged as follows:
(a) The jockey pump stop point should equal the...
hi stookeyfpe, let me briefly explain what I meant in my opening thread...
Our local AHJ has been practising British Standards for ages, most likely passed down from post-colonisation days.
Since the day I have been introduced to fire pumps, we have always been taught to size out two identical...
Dear all,
After studying NFPA 20 for some time, I feel like there are some major practices in NFPA that is different to anything we've been learning from our local AHJ in Asia.
The biggest one that's been bugging me, and I would like to discuss today to have a better clarity, is the topic on...
Hi LittleInch, thanks for the response.
I think an illustration on my concerns would be easier to understand as indicated by the red arrows in below image:
Basically I'm not sure if the PRV/MRV of this type can prevent such as above from happening as the source of backflow can come from the...
While designing the main relief valve discharge piping, we decided to connect this pipe to the downstream of the test pipe that is returning to an above ground storage tank.
However, the return pipe going into the storage tank is elevated above the return pipe itself.
If the test pipe were to...
hi sk designer,
thanks a lot for the clarification, based on this simple sentence I will assume we only need one test connection at each line! (and save some globe valves)
Hope someone could help me out.
As it is our first time designing a NFPA pump sensing line, the common diagram always features two test connections at A (near the control valve) or B (near the control panel pressure switch), with 2 sets of globe valves at each point.
However, I have also seen...