Part No Px Pipe Size (NPS with Sch80 WT) P Pipe Size, NPT L B F Work. Press, (psi) FAV-4PSW-8N-SS 1/4 1/2 38.9 14.2 27.0 4900 FAV-6PSW-8N-SS 3/8 1/2 38.9 14.2 27.0 4900 FAV-8PSW-4N-SS 1/2 1/4 37.3 19.1 22.2 7500 FAV-8PSW-8N-SS 1/2 1/2 43.7 19.1 27.0 4900