All the pressure, and the flange is made of high-quality alloy steel forgings, non-destructive Ultrasonic Flaw detection and sec 1, and all the pressure, and the flange are made of high-quality alloy steel forgings, and with no damage flaw detection, and ensure security. 2, gate valves, valve seat and the needle valve, the valve stem in heap (fuel injection) solder alloy.3, the main part is the ...