Major structures of forged steel check valve:   
1. BODY. The body is forged steel and designed to the basic dimensional requirements of the applicable specifications such as API 602 and ASME B16.34. The body is available in both the full or standard port design. It is also available in either T-Pattern or Y-Pattern configurations.
2. COVER. The cover is forged steel and designed to the basic dimensional requirements of the applicable specifications such as API 602 and ASME B16.34.
3. BODY-COVER JOINT. Two different cover joint designs are available. These are either the bolted cover or the threaded and seal welded type.
4. GASKET. The bolted cover joint design valve uses a contained, controlled compression, spiral wound type gasket
5. COVER BOLTING. The cover bolting is manufactured of alloy steel in accordance with the requirements of the applicable specifica-tions such as API 602 and ASME B16.34.
6. SEAT. The body seat for the piston and ball check valves is an integral weld overlay and is part of the valve trim. The swing check valve is supplied with a separate seat ring which is pressed into the valve body and wedged into place, forming a seal with the body.
7. PISTON, BALL OR DISC. The piston, ball or disc is forged steel and is part of the valve trim. The seating surface of the piston and ball check is of the tapered or plug type design. The seating surface of the swing check is of the flat seat design.
8. SPRING. The spring is optional and supplied only upon request.