What were the requirements for installing a fire pump on a pipe scheduled system?
Are you talking about sizing?
Are you asking if one is required or was required?
I have a pipe schedule system with a fire pump. I have only dealt with
hydraulic systems with pumps and was wanting to find out what kind of
parameters would a pipe scheduled system require a pump.
I am not sure of the date of install. All the placards are missing. The
pump is supplied by a municipal water supply so that leaves out no water
supply. I have been told that available pressure on the last sprinkler in
a remote area but that seems to be leaning towards hydraulics. Would like
to have something in a code???
In chapter 11 of NFPA 13 there is a table dictating the amount of require
pressure at the most remote head. You then have to account to loss of
elevation and a few other components to ensure enough pressure is there and
enough flow is available at the base of the riser.
Sean, I am not looking for calculation. I have already performed my
analasis. I am looking to see if anyone out there knows of the pump
requirements before hydraulic calls were used. I know that Automatic and
Grenau (excuse spelling) started using hydraulic calcs around 1972.
Sorry have to look at 13, and have not delt with a pipe system in awhile , but like any other system, if the normal main pressure can not supply the system, than a pump is needed.
And not a desingern, so
have you looked at table 126.96.36.199 NFPA 13 2010 edition
Dictates how much water you need.
So what is the incoming main pressure, before it hits the pump?
Section 188.8.131.52 is the section you are looking for. It gives you the minimum pressure required at the base of riser based on the occupancy. Only light and ordinary occupancies can be pipe scheduled. You then have to add required residual pressure for the height of the highest sprinkler head and pressure loss for any backflow device. These two pressure requirements along with the minimum required pressure at the base of riser (Table 184.108.40.206) will give you the minimum pressure required. Based on this method, a fire pump would be required if you have a city water static pressure of probably 30 or less depending on the elevation of the system. The backflow device, if present, is probably a high pressure loss device losing around 10 psi. If your highest sprinkler is at 20ft, your are losing and addition 8.6 psi. With poor city water, you could very easily get into requiring a fire pump to boost pressure. Hopefully this was helpful.
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