What is wafer type check valve(also called butterfly type check valve)? 

1. How the wafer type check valve works? 

Wafer type check valve (also known as butterfly type check valve, butterfly wafter check valve, wafer butterfly type check valve) is one kind of check valve which can automatically open and close the disc driven by the flow force of the medium, and is usually used to prevent the medium from flowing back. It is also called non-return valve, one way valve, re-flux valve, cut off valve and back pressure valve. 

The wafer type check valve works automatically. Under the driving of the fluid pressure flowing in one direction, the valve disc will open; 

When the fluid flows in the opposite direction, the fluid pressure and the weight of the disc will force the valve disc to close, to cut off the flow. 

2. what kind of pipelines where wafer type check valve can be used: 

Wafer type check valve is suitable for various pipelines with nominal pressure PN1.0MPa～42.0MPa, Class150～2500；with nominal diameters DN12～1200mm、NPS1/2～48; working temperature -196～540℃, to prevent the medium from flowing back; with different material used for wafer type check valve, the wafer type check valve can be used for various mediums such as water, steam, oils, nitric acid, acetic acid, strong oxidizing mediums and urea,etc. 

3. What is the design standards and specifications: 

1. Design and manufacturing standard: API 594、API 6D、JB/T 8937、DIN3356;

2. Face to face standard: API 594、API 6D、DIN 3202、JB/T 8937；

3. Pressure-temperature rating standard: ANSI B 16.34、DIN 2401、GB/T 9124、JB/T 74；

4. Test and inspection standard: API 598、GB/T 13927；

5. Pipe flange standard: JB/T 74～90、GB/T 9112～9124、ANSI B 16.5、DIN 2543～2548、GB/T 13402、API 605、ASME B 16.47; 

4. what is the structural characteristics of wafer type check valve: 

4.1. the face to face length of the wafer type check valve is short, and its face to face length is only 1/4～1/8 of the traditional flange check valve. 

4.2. The wafer type check valve has small size, light weight, and its weight is only 1/4～1/20 of the traditional flange check valve; 

4.3. The valve disc of the wafer type check valve can close quickly, and the water hammer pressure is small. 

4.4. In terms of installation, the wafer type check valve can be installed horizontal and vertical pipelines systems. 

4.5. The flow channel of the wafer type check valve is smooth, and its fluid resistance is small; 

4.6. The wafer type check valve has sensitive action and good sealing performance; 

4.7. The disc stroke of the wafer type check valve is short, and the impact force occurred when the wafer check valve is closing is small; 

4.8. The overall structure of the wafer type check valve is simple and compact, and it has beautiful appearance; 

4.9. The wafer type check valve has a long service life and strong reliability; 

Apart from the wafer type check valve, there are some other check valves: