A valve that is designed to allow the fluid to flow in a given direction but closes to prevent backflow. Types include swing check, tilting disc check and wafer check. Check valves (also called non-return valves) are usually self-acting.

API Cast Steel Check Valve's specification is as follow:

Quoting Standards
Bolted Cover
Flanged or Butt-welding ends
Manufacture in accordance with API 6D
Face to Face/End to End Dimensions to ANSI B 16.10
Flange Dimensions to ANSI B 16.5
Butt-welding End Dimensions to ANSI B 16.25
Valve tested to API 6D

Product Main Usage
API Check Valve is suitable to Class150～600Lb and Working Temperature -29℃ to 550℃ in Oil,
Chemical Industry, producing medicine, fertilizer and Electric Industry. Its suitable is water, oil, steam,
acid medium etc.
Product Construction
1. Design conforms to GB12236, reasonable construction, reasonable seal, and perfect performance.
2. Disc and seat sealing face are made of iron alloy or stellite, over-laid and hard faced wearable, high-temperature proof, rust-proof, scratch-proof, long time service.
3. Suitable for all kinds of flange and flange face, meet all kinds of requirement of project and client.
4. Large scale of body material for selection, gasket is adoptable according to actual situation or clients' requirement, applicable for all kinds of pressure rating, temperature and media.
5. Disc goes across the pin, minimum the impact of closure.
6. Connect of pin and disc is inside constructed, non-leakage, reliable application.