... brass 2,Standards: American and DIN standard 3,1-1/2"-24 nps wafer check valve:1,30years focus on QA2 ... valve, check valve, brass gate valve, and brass ball valveavailable2) Materials: cast iron, cast steel, carbon steel, and brass3) Standards: American and DIN ... standard4) We can supply various sizes of valves according to customers' requirements nps wafer check valve