Oil & Gas Check Valves: UK Procurement & Technical Selection Guide What is Check Valve in Oil and Gas? A check valve is a device which is installed to control flow in one direction and which automatically closes when the fluid tries to flow in the opposite direction. It can be used as protection against backpressure, water hammer and backflow events on both gas and liquid pipelines in hydrocarbon service to protect pumps, compressors and downstream equipment. Provide our independent sourcing team with process medium, pressure, temperature and pipe size to be matched with a bespoke check valves oil gas UK specification. Request a Quote Primary Functions: Preventing Reverse Flow and Water Hammer in Hydrocarbon Systems A non return valve uk specification is a critical parts of a hydrocarbon system in oil and gas pipelines, owing to the high differential pressure in such systems. The fluid column may turn back in milliseconds when a pump stops, or a compressor trips. This cause a reverse flow that creates a pressure spike called water hammer that can cause pipe joints to leak, cause gasket failure and destroy valve seats. A correctly installed check valve that is to be installed on hydrocarbons lines shuts off almost instantly when the flow direction changes, preventing the possible pressure build up from reaching the upstream side of the pipeline. With respect to the natural gas, crude oil or condensate transport of gas and liquid pipelines, the use of backflow prevention is not just a best practice, it is a required safety measure as per UK pressure systems legislation. For a broader view of flow control components, explore our industrial valves category covering check, gate, globe, and ball configurations. Main Types of Check Valves for Oil & Gas Service The question of which check valve for oil and gas is suitable depends on the pressure class, pipe size, flow speed and space requirements when the engineers ask about this. The four dominant check valve types oil gas applications rely on: Swing Check Valve A hinged disc opens when flow is through it and closes automatically due to gravity or back flow. It provides a complete flow path and low pressure drop and can be used in large diameter liquid lines in refineries. Dual Plate Check Valve The discs are self-closing and spring loaded. The comparison of the dual plate valve with the swing plate valve is not so straightforward and paves the way for dual plate to be the better option in compact offshore skid packages where rapid closure prevents water hammer. Axial (Nozzle) Check Valve A single disc slides axially on a seat nozzle. It provides the fastest closure time, making it the preferred choice for a check valve for compressor discharge where even a 50-millisecond delay causes severe hammer. Piston Check Valve A piston is guided in a linear motion in the body. It handles high-pressure gas service well and is common in upstream production separators. For actuated flow control, MAC Valves offers pneumatic and electric actuator options that integrate with DCS and SCADA systems for remote isolation. Specification Checklist Parameter Specification Options Why It Matters Pressure Rating Class 150 to Class 2500 (ASME B16.34) Confirm against system design pressure including transients and water hammer surges Size Range DN15 to DN600 (NPS ½" to 24") Match to line size and flow velocity; verify bore type (full or reduced) Materials A105, SS316, Duplex 2205, Super Duplex 2507, Inconel 625, Hastelloy C-276 Required for corrosive, chloride, sour (H₂S/CO₂) or high-temperature service Closure Speed 50 ms to 500 ms depending on valve type Must prevent water hammer at pump or compressor trip; axial and dual plate are fastest End Connections Flanged (BS 1868 / ASME B16.5), Butt-Weld, Threaded (NPT / BSP), Wafer Verify thread form and flange rating; NPT and BSP are not interchangeable Seat Material PTFE, RPTFE, Metal-to-Metal, RPTFE Overlay Match to process temperature and medium; PTFE max ~200 °C, metal seats for high-temp sour Certification API 594, API 6D, NACE MR0175, PE(S)R 2016, NORSOK M-630 Required for sour service, UK offshore compliance and high-integrity documentation packs Material Selection for Severe Environments The selection of the materials of the check valve is the most crucial decision for sour gas and high temperature application. On North Sea platforms, and in onshore refineries, the process medium may contain H2S, CO2 and chlorides which can cause damage to normal carbon steel in only weeks. The industry standard for a check valve material for H2S service is Super Duplex 2507 (UNS S32750) which has a minimum yield strength of 550MPa and excellent resistance to sulphide stress cracking. For more aggressive applications, Inconel 625 or Hastelloy C-276 trims are recommended for the disc, seat and stem. A super duplex check valve oil gas specification is now standard for most North Sea topside installations. Seat materials also matter. For a non return val…