Regarding the ten times diameter of pipe keeping between fire pump suction flange and the fittings/assemblies as per “NFPA 20 Section 4.27.3& FIGURE A.4.14.6 Right and Wrong Pump Suctions”
It is making some confusion if we are using a strainer in the suction, is it required to keep ten times diameter from strainer to pump suction flange. (the term “assembly” used in NFPA is applicable for strainer also?)
4.27.3 Devices in Suction Piping. Where located in the suction
pipe of the pump, check valves and backflow prevention
devices or assemblies shall be located a minimum of 10 pipe
diameters from the pump suction flange.