Hydraulic Calculations
Hydraulic Calculations
(OP)
Hello Everyone..this is my first time here and what I have read so far is pretty impressive.
I have just started as a fire protection designer. I have very limited knowledge about this industry. I was wondering if you can help me with a project I am currently working on.
It is a Wellness center (Mix occupancy A-1, A-3, B), it has two swimming pools, tracks, gym, small auditorium, therapy exam rooms, general spaces (offices, conference rooms etc).
General information about this building:
>2 stories = Garden Level (-15 ft), Main Level (+18 ft)
>44 static, 42 residual, 940gpm flowing a 2.5" nozzle
>112,000 square feet (55,000+ square feet per floor)
>Standpipe is not required since building is a single story
I am trying to calculate whether or not I need a fire pump or is the street water pressure sufficient to exclude the fire pump. This is what I calculayed.
>I am assuming this will be a light Hazard building (Am I correct?)
>8" CI imcoming water line (300 feet) = 0.1 psi
>RPZ = 11 psi
>8" pipe after RPZ (30 feet (header for sprinkler risers)) = 0.01 psi
>4" pipe from garden level to most remote area on Main level (565 feet + 170 feet for fittings = 73ft) = 9.2 psi
>Elevation is 18ft x .433 = 7.8psi
>Sprinkler, using 13 gpm (LH), k=8.0 this gives me = 2.6 psi
For a total of 31 psi I am still below the city water curve....So I came to the conclusion I do not need a fire pump.
Did I do this correctly? Am I missing somthing in my calcs?
Any advice would be greatly appreciated....
Thank you very much
I have just started as a fire protection designer. I have very limited knowledge about this industry. I was wondering if you can help me with a project I am currently working on.
It is a Wellness center (Mix occupancy A-1, A-3, B), it has two swimming pools, tracks, gym, small auditorium, therapy exam rooms, general spaces (offices, conference rooms etc).
General information about this building:
>2 stories = Garden Level (-15 ft), Main Level (+18 ft)
>44 static, 42 residual, 940gpm flowing a 2.5" nozzle
>112,000 square feet (55,000+ square feet per floor)
>Standpipe is not required since building is a single story
I am trying to calculate whether or not I need a fire pump or is the street water pressure sufficient to exclude the fire pump. This is what I calculayed.
>I am assuming this will be a light Hazard building (Am I correct?)
>8" CI imcoming water line (300 feet) = 0.1 psi
>RPZ = 11 psi
>8" pipe after RPZ (30 feet (header for sprinkler risers)) = 0.01 psi
>4" pipe from garden level to most remote area on Main level (565 feet + 170 feet for fittings = 73ft) = 9.2 psi
>Elevation is 18ft x .433 = 7.8psi
>Sprinkler, using 13 gpm (LH), k=8.0 this gives me = 2.6 psi
For a total of 31 psi I am still below the city water curve....So I came to the conclusion I do not need a fire pump.
Did I do this correctly? Am I missing somthing in my calcs?
Any advice would be greatly appreciated....
Thank you very much





RE: Hydraulic Calculations
RE: Hydraulic Calculations
RE: Hydraulic Calculations
RE: Hydraulic Calculations
Your first point: Unfortunately that was the infromation provided to me by the Civil engineer. Do you think I should ask for another hydrant flow test then?
Your second point: I typed the wrong number...you are correct it should be a total of 735 feet (pipe length and fittings)I The flow rate I calculated (0.10gpm x 1500ft=150gpm) I added 30% to 150gpm which gave me 195 gpm. So I used 195 gpm for the flow rate. I chose the 8" RZP based on 195 gpm flow.
Your third point: Current desig is for an 8" RPZ...I was thinking of having an 8" header where 4 alarm check valves can be manifolded. That way I can have each floor divided into two zones. I designed for each alarm check valve to be 4" so that a 4" main can be routed to the most remote area.
Again thank you
RE: Hydraulic Calculations
Your account is a light occupancy and my archices indicate the sprinkler flow range and the hose stream requirement in the notations. One thing that I am amazed is the large sprinkler orifice size which has a K=8 telling me that it is a 17/32" orifice diameter. Normally such large orifice would be used in hazardous occupancies such as paint storage areas.