1) Forged steel check valves conform to ASME B16.34
2) Each tested according to API 589, and marking is per MSS SP-25
3) Three bonnet designs
    a) Bolted
    b) Welded
    c) Pressure seal
4) Three different design configurations
    a) Piston check
    b) Ball check
    c) Swing check
5) Investment casting
6) Working pressure: 200 PSI WOG
7) Temperature range: -20 - 232°C
8) Materials: WCB, SS 316 and SS 304
9) Sizes: 1/4" - 4"
10) Threads: NPT, BSPT, BSP and DIN259/2999