Characterization valve, also known as one-way valve or check valve, depending on the force of the flow of the pipeline in the medium itself generated automatically turned on and off, is an automatic valve. Check for the pipeline system, its main role is to prevent the media back, to prevent the pump and its drive motor reverses, and discharge the container media. Pressure valve can also be used for more than one of the primary system pressure may rise to an auxiliary system supplies the pipeline. Structural features 1, compact and reasonable product structure, reliable sealing, excellent performance. 2, small size and light weight. 3, a wide range of applications. 4, valve closed fast, quick action. 5. Close the impact is small, easy to produce water hammer phenomenon. 6, the flow smooth, fluid resistance. Design Specification Design Standard: API 6D, ASME B16.34, API 594, BS 1868, GB / T 12235, GB / T 12236, JB / T 8937 Structure Length: ASME B16.10, API 6D, GB / T 12221 connection standard : ASME B16.5, ASME B16.47, ASME B16.25, GB / T 9113, JB / T 79, HG / T 20592 Pressure test: API 598, API 6D, GB / T 13927, GB / T 26480 pressure Temperature Rating: ASME B16.34, GB / T 12224 Performance parameters main material: carbon steel, stainless steel, alloy steel nominal diameter: NPS 2 "~ NPS 48" DN50 ~ DN1200 Pressure range: CL150 ~ CL2500 PN10 ~ PN420 Operating temperature: -196 ℃ ~ + 600 ℃ Application: suitable for pipeline petroleum, chemical, pharmaceutical, fertilizer, power industry, and other conditions of low temperature.