KF16 flange pressure relief valve for vacuum chamber (< 1.5 Psig)ISO KF NW16 KF16 flange Prevent excessive positive pressure build up in pumps or vacuum chambers Spring loaded piston pushed open when chamber pressure > 1. 5 psig or 16. 2 psia or 1116 mbar Spring loaded piston close when chamber pressure < 16. 2 psia (1. 5psig) or 1116 mbar Piston open @ PISA = 16. 2 psia + 0. 3 PSI or 1. 5 psig + 0. 3 PS Made of stainless steel 304