sprinklernotes
Pressure-Regulating Devices in Suction Piping
You asked the following question: “Are pressure-reducing valves allowed in the
suction pipe of a fire pump?”
In response to your question, we have reviewed NFPA 20, Standard for the
Installation of Stationary Pumps for Fire Protection, 2019 edition. Our
informal interpretation is that pressure-reducing valves are not permitted to
be installed in fire pump installations.
NFPA 20 does not permit the use of pressure-regulating devices, which includes
pressure-reducing valves, to be installed in fire pump piping as a means to
reduce the system pressure below the maximum-rated pressure.
4.7.7.2* Pressure relief valves and pressure-regulating devices in the fire
pump installation shall not be used as a means to meet the requirements of
4.7.7.1.
This limitation is restricted to the pipe under the scope of NFPA 20 which
includes all pipe, fittings, and appurtenances from the connection to the water
supply to the system side of the discharge control valve.
4.16.1.1 The suction components shall consist of all pipe, valves, and fittings
from the pump suction flange to the connection to the public or private water
service main, storage tank, or reservoir, and so forth, that feeds water to the
pump.
4.17.1 The discharge components shall consist of pipe, valves, and fittings
extending from the pump discharge flange to the system side of the discharge
valve.
Anything downstream of the discharge control valve would be under the
jurisdiction of the installation standard for the fire protection system that
the fire pump is supplying and anything upstream of the connection to the
source would be under the jurisdiction of the applicable installation standard
and/or water purveyor.
