Dear NFPA,
Here in our Petroleum Refinery we have some doubts about listed valves (or fittings) on the fire fighting piping systems.
Please according with NFPA updated criteria, which material is recommended for “Fire fighting pipe systems and accessories like gate valves installed at the firefighting pump discharge?.
We have requested valve vendors to provide new valves and all they propose ASTM A536 valves type instead a single Carbon Steel valve. Also we request RF type flanges for install in our existing RF pipes but they only provide FF type flanges.
Please could you explain this more clearly?.
Regards
You should specify to your vendors that valves and fittings must be listed for fire protection service. That means the items and their data sheet's must have one of the following marks: UL, FM, VdS, LPCB, MEA, etc.
Most fire protection valves larger than DN 50 (2") are made of ASTM A536 ductile iron. Some manufacturers (Nibco is one of them) make some valves out of cast iron. I do not know any manufacturer that makes fire protection valves in carbon steel. Personally, I think ductile iron is the better material for big fire protection valves.
Regarding the flanges, as far as I know, most fire protection valve flanges are flat face. You should ask your vendors to also supply ring adapters.