DN200 PN16 ASTM A351 GR. CF8M FEMALE NPT THREADED WCB FLANGED END CHECK VALVE

What is a Check Valve?

The valve that used to prevent backflow in a piping system is known as a check valve. It is also known as a non-return valve or NRV. The pressure of the fluid passing through a pipeline opens the valve, while any reversal of flow will close the valve.

It allows full unobstructed flow and automatically shuts as pressure decreases. The exact operation will vary depending on the mechanism of the valve.

Specifications:

• Swing Type
• Working pressure: 200psi WOG
• Body: ASTM A351 Gr. CF8M
• Disc: ASTM A351 Gr. CF8M
• Packing: PTFE
• End Connections: Female NPT Threaded

Parts of Non-Return Valve

It is consists of body, cover, disk, hinge pin, and seat ring. In the image below you can see the parts of the valve.

Types of Valves

The type of disk will decide the type of valve. Most common types of Check valves are

• Swing Type.
  • Top Hinged
  • Tilting disk
• Lift Type
  • Piston Type
  • Ball type
• Dual Plate Type
• Stop Check Valve

Swing Check Valve

The disc in a swing type valve is unguided as it fully opens or closes. This Valve operates when there is flow in the line and get fully closed when there is no flow. Turbulence and pressure drop in the valve is very low. Disk and seat designs can be of metal to metal or metal to composite.

Tilting Disc Check Valve

The tilting disc type valve is designed to overcome some of the weaknesses of conventional swing type valves. The design of the tilting disk enables the valve to open fully and remain steady at lower flow rates and close quickly when the forwarding flow stop.

Ball Type and Plug Type Lift NRV

The seat design of a lift Check valve is similar to a Globe valve. A piston or a ball is usually used as a disk.

Lift Check valves are particularly suitable for high-pressure service where the velocity of flow is high. The disk is perfectly set on the seat with full contact. They are suitable for installation in horizontal or vertical pipelines with upward flow.

Dual Plate / Dual Disc Check Valve

A dual plate check valve is known as a butterfly check valve, Folding Disc Check Valves, double-disc, or splits disc check valve. As the name suggests, two halves of the disk move towards centreline with the forward flow and with reverse flow two halves open and rest on the seat to close the flow (Flapping action).

Stop Check Valve

Stop Check Valve is a combination of a lift check valve and a globe valve. It can either be used as a check valve or as an isolation (stop) valve like a globe valve. These valves can be closed with the help of a stem that is not connected to the valve disc during normal operation and make it possible to use these valves as a regular NRV.