The check valve is a kind of one-way valve, which relies on the pressure of the medium to realize the metal seal between the spool and the valve body, the greater the medium pressure, the better the sealing performance. The check valve design and manufacture of APImeivalve fully meet the requirements of API spec 6A and can be used interchangeably with domestic and foreign equipment conforming to API spec 6A. The valve body is made of alloy steel forging, with strong mechanical properties, and can withstand high pressure, with safe and reliable performance. The bonnet and valve body are bolted together, and the seal is the sealing ring on the bonnet and the inner wall of the valve body. The sealing performance is reliable. It provides minimal assembly clearance between the bonnet and body (designed to be 0), thereby reducing erosion of bolts and holes by corrosive media and reducing bolt loads. Hard alloy is hard-faced on the core and sealing surface of the valve body so that it has good wear resistance and corrosion resistance. The core material should use sulfur-proof steel, and other parts should use the method of limiting hardness so that the valve can be used in an environment containing H2S. Install the valve body into the pipeline according to the flow direction on the valve body. The valve core by the upper and lower pressure to achieve movement and sealing so that the valve core can not be stuck. Technical Parameters 1. One-way flow of the working medium. 2. Working pressure: 2,000 psi 20,000 psi 3. Nominal diameter: 2.1/16 4.1/16 (52mm 103mm) 4. Working medium: oil, natural gas, mud, H2S and CO2 gas 5. Operating temperature: -46 C 121 C (LU level) 6. Material level: AA, BB, CC, DD, EE, FF, HH 7. Specification level: PSL1 4 8.Performance level: PR1 2