SprinklerDesigner2
Mechanical
- Nov 30, 2006
- 1,251
I'm a NICET layout technician and I don't do engineering. I lay out sprinkler systems using the appropriate NFPA standards as a cookie cutter.
I am looking at bidding a large project consisting of a fire pump, five standpipes and full sprinklers on every floor. The state where the job is located does not allow manual standpipes and to top it off both the state fire marshal rules and the state EPA requires all fire pumps to maintain a minimum suction pressure of 20 psi @ 150% of capacity.
Drawings and specifications don't have anything pertaining to the size of the fire pump with the exception it have a 125 HP electric motor. Nothing about gpm or psi.
The project drawings are sealed and signed by a registered professional engineer.
I know I can make this work with a 1,000 gpm pump and, while I am not done checking, with a 125 HP motor the pressure would range between a low of 102 psi and 125 psi.
Drawings consist of a plot plan showing an 8" line extending from an 8" city watermain to a little tiny pump house (split case, good luck fitting everything in there with the required backflow assembly) and then lines feeding the standpipe. The extend of the sprinkler drawings are circles where heads are supposed to be.
I attempted to set up a flow test but was told I couldn't because a contractor was working changing out some underground somewhere in the facility and they didn't want surges.
I do have a partial flow test that was given to me by the facilities engineering department that indicates a static of 48 psi and residual of 28 psi flowing through a 2 1/2" hydrant butt. Using a discharge coefficient of 148 for the hydrant it appears we can expect 48 static, 28 residual @ 700 to 800 gpm flowing.
I expressed my concerns in an RFI and received the following response:
"The fire sprinkler contractor is required per the plans and specification to design, provide, and install complete building sprinkler coverage, except for areas noted herein, with automatic wet system in accordance with NFPA 13."
I had a two page RFI detailing my concerns and what is required and this is all I get back?
With five standpipes would it be unreasonable for me to assume the engineer of record checked the availability of water knowing a minimum of 1,250 gpm would be required for the standpipes? Would it be reasonable of me to conclude the engineer knows of the state minimum requirement of having 20 psi at the pump suction flange when the pump is operating at 150%?
My big question is when it doesn't work WHO PAYS for the upgrades to whatever is required (tank?) and the delay in the project that has liquidated damages that would take me out in a couple weeks?
If PE's want to get into fire protection, because there's money in it and times are tough, shouldn't they be required to know what they are doing or can they just toss all the responsibility onto the sprinkler contractor?
I am looking at bidding a large project consisting of a fire pump, five standpipes and full sprinklers on every floor. The state where the job is located does not allow manual standpipes and to top it off both the state fire marshal rules and the state EPA requires all fire pumps to maintain a minimum suction pressure of 20 psi @ 150% of capacity.
Drawings and specifications don't have anything pertaining to the size of the fire pump with the exception it have a 125 HP electric motor. Nothing about gpm or psi.
The project drawings are sealed and signed by a registered professional engineer.
I know I can make this work with a 1,000 gpm pump and, while I am not done checking, with a 125 HP motor the pressure would range between a low of 102 psi and 125 psi.
Drawings consist of a plot plan showing an 8" line extending from an 8" city watermain to a little tiny pump house (split case, good luck fitting everything in there with the required backflow assembly) and then lines feeding the standpipe. The extend of the sprinkler drawings are circles where heads are supposed to be.
I attempted to set up a flow test but was told I couldn't because a contractor was working changing out some underground somewhere in the facility and they didn't want surges.
I do have a partial flow test that was given to me by the facilities engineering department that indicates a static of 48 psi and residual of 28 psi flowing through a 2 1/2" hydrant butt. Using a discharge coefficient of 148 for the hydrant it appears we can expect 48 static, 28 residual @ 700 to 800 gpm flowing.
I expressed my concerns in an RFI and received the following response:
"The fire sprinkler contractor is required per the plans and specification to design, provide, and install complete building sprinkler coverage, except for areas noted herein, with automatic wet system in accordance with NFPA 13."
I had a two page RFI detailing my concerns and what is required and this is all I get back?
With five standpipes would it be unreasonable for me to assume the engineer of record checked the availability of water knowing a minimum of 1,250 gpm would be required for the standpipes? Would it be reasonable of me to conclude the engineer knows of the state minimum requirement of having 20 psi at the pump suction flange when the pump is operating at 150%?
My big question is when it doesn't work WHO PAYS for the upgrades to whatever is required (tank?) and the delay in the project that has liquidated damages that would take me out in a couple weeks?
If PE's want to get into fire protection, because there's money in it and times are tough, shouldn't they be required to know what they are doing or can they just toss all the responsibility onto the sprinkler contractor?