American Standard check valve, also known as check valve (check valve), the design and manufacture of products in line with the American National Standard ANSIB16.34, the American Petroleum Institute standard APl6D requirements. American Standard check valves have a swing-opening valve flap and a straight-through flow path, which can be installed in horizontal and vertical pipelines. The rocker pin adopts internal structure, which reduces the shortcomings of external leakage. Valve body, bonnet is bolted, under high pressure (PN ≥ 10MPa). The center flange adopts internal pressure self-sealing structure, which makes the American Standard check valve small in size, light in weight and reliable in sealing.