Check Valves         

Function:

Non-return Check Valve or one-way Check Valve is a mechanical device, a valve, which normally allows fluid (liquid or gas) to flow through it in one direction only.

Operation:

  • The main mission of a Check Valve is to avoid back pressure in the process (avoid that the flow is switching direction)
  • A Check Valve can also be used for isolation purpose.
  • There will normally be regulations telling how many and in which location Check Valves are to be installed in the process.

Design:

  • As for most valves there are a lot of different designs of Check Valves. The basic design is a Duo Check Valve with two discs mounted on an hinge pin in the center of the Check Valve. The Check Valve has a standby closed position with springs pushing the discs towards the seats. These valves are designed for installation on a horizontal line where the hinge pin is placed in a vertical position.
  • To reduce space and weight these Check Valves are often delivered as wafer valves.

Other types of Check Valves:

  • Swinging Check Valve
  • Tilting Disc Check Valve
  • Piston Check Valve
  • Non slam Check Valve
  • Needle Check Valve
  • Nozzle Check Valve