ASTM A182 F91 pipe fittings are forged,commonly used to be socketed or threaded connecting with the ASTM A213 T91, A200 P91,A336 F91,A199 T91,A369 FP91,A335 P91 steel pipes.
The ASTM A182 F91 pipe fittings has its unique characteristics to use:
a.It is usually used to connect with small size pipe or fittings,1/8″ to 4″.
b.The connection method is socket welding or threaded connection,so it is more convenient to use.But you must be careful for the design and choice of the connection standard or size.
c.It could be used for circumstances of high temperature-600-650℃
So it could be used in industry field,like oil,gas,power plant,water treatment,chemical-industry etc.(What are ASTM A182 F91 pipe fittings?)