... monel. Shaft: 416S. Sand316S. S, 17-4PH. Seat: EPDM, high temperature EPDM, food grade EPDM, NBR, abrasive resistant NBR, Viton, high ... temperature Viton, Hypalon, Silicon rubber PTFE over EPDM, PTFE over NBR, ... valve seat is made of PTFE, which is suitable for a temperature between -30º C and 230º