Check Valve

(CHKV) Check valves are designed to allow the fluid/vapor to flow in only one direction to prevent backflow. There are four basic types: diaphragm check, lift check, swing check, and tilting-disk check. Check valves are also called non-return valves and are usually self-acting.

Check Valve Types:

• Ball Check Valve
• Diaphragm Check Valve
• Dual Plate Lug Check Valve
• Dual Plate Flange Check Valve
• Dual Plate Wafer Check Valve
• Lift Check Valve
• Piston Check Valve
• Stop Check Valve
• Swing Check Valve
• Tilting-Disk Check Valve

Applicable Codes

The following is a list of codes applicable to check valves:

• API Codes
  • API Spec 6D - Specification for Pipeline Valves, End Closures, Connectors and Swivels
  • API Std 594 - Check Valves: Flanged, Lug, Wafer and Butt-welding

• ASME Codes
  • ASME B16.5 - Pipe Flanges and Flanged Fittings: NPS 1/2 through 24
  • ASME B16.10 - Face to Face and End to End Dimensions of Valves
  • ASME B16.20 - Metallic Gaskets for Pipe Flanges: Ring-Joint, Spiral-Wound, and Jacketed
  • ASME B16.25 - Buttwelding Ends
  • ASME B16.34 - Valves Flanged, Threaded and Welding End

• BSI Codes
  • BS 1868 - Specification for steel check valves (flanged and butt-welding ends) for the petroleum, petrochemical and allied industries
  • BS 1873 - Specification for steel globe and globe stop and check valves (flanged and butt-welding ends) for the petroleum, petrochemical and allied industries
  • BS 2080 - Specification for face-to-face, centre-to-face, end-to-end and centre-to-end dimensions of valves
  • BS 5152 - Specification for cast iron globe and globe stop and check valves for general purposes
  • BS 5153 - Specification for cast iron check valves for general purposes
  • BS 5154 - Specification for copper alloy globe, globe stop and check, check and gate valves
  • BS 5160 - Specification for steel globe valves, globe stop and check valves and lift type check valves
  • BS 5352 - Specification for steel wedge gate, globe and check valves 50 mm and smaller for the petroleum, petrochemical and allied industries

• MSS Codes
  • MSS SP-42 - Class 150 corrosion-resistant gate, globe, angle, and check valves with flanged and butt-weld ends.
  • MSS SP-61 - Pressure testing of steel valves.
  • MSS SP-71 - Cast iron swing check valves, flanged and threaded ends.
  • MSS SP-80 - Bronze gate, globe, angle, and check valves.
  • MSS SP-84 - Steel valves‚Äîsocket welding and threaded ends.