Description: API 6A Check Valve, also referred to non-return valve, or one-way valve, is a valve that normally allows fluid (liquid or gas) to flow through it in only one direction. An important concept in check valves is the cracking pressure which is the minimum upstream pressure at which the valve will operate. We can produce both swing type check valve and lift type check valve. Available in bore sizes from 1-13/16" to 7-1/16" and pressure ratings from 2,000 to 15,000 PSI. The standard material is forged AISI4130 alloy. All of our Check Valves are fully designed, manufactured, and tested as per API 6A and API 16C standards and have been widely used on oilfield wellhead Christmas tree and manifolds with reliable performance.