Oil & Gas Check Valves UK: Procurement Guide

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 valve for sour gas under elevated temperatures, metal-to-metal seats with RPTFE overlay are safer than PTFE and RPTFE seats for clean hydrocarbons up to 200°C. . For lighter-duty utility lines, a PTFE check valve rated at 1 MPa provides reliable backflow protection in compressed air and water systems.

UK Offshore & Onshore Regulatory Compliance

Procuring check valves oil gas UK installations must comply with regulations that differ from US or EU requirements:

• PE(S)R 2016 — Enforced by OPSS in Great Britain, this mandates that pressure equipment above 0.5 bar carries a UKCA or CE mark and a Declaration of Conformity.

• PSSR 2000 — Enforced by HSE, requiring documented risk assessments for pressure systems above 0.5 bar.

• API 594 — The primary design and testing standard for wafer, wafer-lug, and double-flanged check valves. An API 594 check valve must pass shell, seat, and stem leakage tests.

• API 6D — Covers pipeline and piping valves for natural gas and crude oil transmission. An API 6D check valve UK specification is common for North Sea subsea and topside installations.

• NACE MR0175 / ISO 15156 — Mandatory for components exposed to sour gas. Materials must be listed in Annex A or B.

• ASME B16.34 — The pressure-temperature rating, dimensions, and testing of steel valves are specified.

• BS 1868 — This was the British Standard for flanged steel valves which remains in current UK onshore specifications.

• NORSOK M-630 — The Norwegian offshore standard widely adopted for North Sea operations.

From Aberdeen’s offshore support base to Teesside’s refineries, Humber’s petrochemical complexes, and the Grangemouth and Immingham refineries, UK installations must carry valid conformity documentation. For offshore check valves UK supplier requirements, NORSOK M-630 and PE(S)R compliance are non-negotiable. A stainless steel ball check valve rated at 400 PSIG with a 100–350°F range is a common mid-pressure utility specification in UK processing facilities.

Procurement Checklist: 7 Technical Parameters Before Issuing an RFQ

How to select check valve for oil gas service comes down to seven parameters. Before issuing an RFQ, confirm each one:

• Process Medium & Composition — Gas, liquid, or two-phase? H2S/CO2 partial pressure? Chloride concentration?

• Pressure-Temperature Rating — Indicate the ASME B16.34 pressure class (Class 300, 600, 900) and maximum operating temperature. The check valve pressure rating oil gas service must exceed maximum working pressure with a safety margin.

• Pipe Size & Connection — Nominal bore (DN/NPS), end connection type (flanged per BS 1868, butt-weld, threaded), and flange face rating.

• Bore Type — Full bore for pigging and low ΔP, or reduced bore for cost-sensitive utility lines.

• Body & Trim Materials — Carbon steel (A105/A216 WCB), duplex (2205), super duplex (2507), or exotic alloys (Inconel 625, Hastelloy C-276). Seat: PTFE, RPTFE or metal-to-metal.

• Closure Characteristics — Closure time requirement (particularly compressor discharge), Fail-safe behaviour, Fire-safe requirement (API 607).

• Standards & Documentation — API 594, API 6D, NACE MR0175, PE(S)R conformity, hydrotest certificate, material test certificates and NORSOK M-630 (applicable).

For smaller-bore instrument lines, an inline check valve in 1-inch stainless steel FNPT × FNPT is a practical solution for backflow protection in control valve manifolds. Browse our full industrial valves range for your next RFQ.

Frequently Asked Questions (FAQ) for Piping Engineers