Many plumbing codes prohibit exposed drainage piping above food service areas. Is the piping considered exposed if there is a drop ceiling below? If so, would drywall ceiling help? Thank you.
JJPellin,
Thank you for the clarification, I thought that riser to upper floors was upstream of PRV. This is let's say ... unusual setup. Pressure reducing valves (PRVs) should be on each floor. Pump needs to be changed in my opinion.
Two questions.
1. How do you know that the PRV (I assume pressure-reducing valve) lowers the pressure back to 200 psi, if you do not have pressure gauge
2. Why do you need 200 psi on the first floor residential? Looks as way too high. 60 psi downstream of the valve seems to be more than adequate
Stookeyfpe, you sited correct section. However I have 4,300 SF on greatest floor, residential floors only 2,600 SF each. I believe that the standpipe is not required in this case. Am I missing something?
Thank you for the valuable comments.
Skdesigner, excellent catch. Stookeyfpe, I am in New York City, surprisingly standpipe is not required here if you are below 75' and do not have occupancy more than 30 people above 55' (subject to area limitations though). Could you please mention potential...
Hi stookeyfpe, thank you for the response. I do not have a standpipe, just sprinklers. For cellar I do not need the pump, only for upper floors because of the elevation the pressure of city main is too low.
I have a project for 7 story building with cellar (parking garage in the cellar, two stories medical offices and others are residential). My understanding - for parking garage I have ordinary hazard 1, in other places it is light hazard. My hydraulic calculations show that there is enough...
Need to specify sprinkler booster pump for one project. Hydraulic calculations show that 75gpm@50PSI will do the job. But in NFPA20 (Centrifugal pump capacities section) there are 50gpm and next capacity is 100gpm. Do I have to comply with this or for booster pump I can choose 75gpm...
Hi cdafd,
You are correct, normally such a building (residential 6 stories) does not require standpipe, but mine is special case, because of location (narrow street) New York City BSA mandated to install the standpipe.
Thank you everybody for the valuable input. By the way, as Jomdoeiowa described, what about acceptance test? Does it mean that in this situation it is necessary to physically bring fire truck to conduct the test (with corresponding charges to the client)?
Travis, as usual you give concise answers, thanks a lot! So as far as I understand in case of wet manual standpipe I do not care about pressure, is this correct? (logically should analyze available water flow though).
Hi Travis, thank you very much for the response. I thought that in most cases automatic standpipe is required and other types installed only in special situations. Am I wrong?
Recently I was asked by code official for 30% safety margin. By the way, when we talk about percentage, what is the proper way to calculate: delta P divided by available pressure or system demand pressure?
Hi Everybody,
I am in New York, and the code requires for standpipes to provide 70 psi at the most remote connection. The pressure at street level is 55 psi. I did hydraulic calculation and it is adequate for sprinkler demand, it is going to be combined system. Does it mean, that in any case...
