check valve 1,Materials: cast iron, cast steel, carbon steel, ... American and DIN standard 3,1-1/2"-24 nps wafer check valve:1,30years focus on QA2,decades experience of ... Canton Fair3,ISO 9001 2000Features:1) Gate valve, butterfly valve, check valve, brass gate valve, and brass ball valveavailable2) Materials: ... supply various sizes of valves according to customers' requirements nps wafer check valve