What pressure rating check valve for gas pipeline?

The pressure class of a check valve for gas pipelines must be selected based on maximum operating pressure, pipeline type (city distribution, compressor station, long-distance transmission), gas medium, temperature fluctuation and safety standards ASME B16.34, API 6D and API 594. The core rule: the nominal pressure rating of the valve must be 1.25–1.5 times higher than the system’s maximum working pressure to handle pressure surges and transient shock from gas backflow (Liu & Zhang, 2025). Two mainstream rating systems are widely used: ANSI Class (LB) for North American export projects and PN (bar) for European & domestic industrial gas piping.

1. ANSI Class Pressure Ratings & Matching Gas Pipeline Scenarios

Class 150 (PN16, Max allowable working pressure 16 bar / 225 psi ambient)

Typical working pressure: ≤10 bar

Applicable pipelines:

Low-pressure city natural gas residential & commercial branch pipelines

Low-pressure compressed air, nitrogen, inert gas auxiliary lines

Small gas burner, boiler gas supply pipes under DN80

Recommended valve types: Wafer dual-plate check valve, spring ball check valve, small swing check valve with soft seal

Limitation: Not allowed for compressor outlet or long-distance trunk gas lines with frequent pressure fluctuations

Class 300 (PN40, Max allowable working pressure 40 bar / 500 psi ambient)

Typical working pressure: 10–25 bar

Applicable pipelines:

Medium-pressure urban gas transmission mains, pressure regulating station outlet pipelines

Medium-pressure compressed natural gas (CNG) auxiliary piping

Refinery low-to-medium pressure fuel gas lines

Recommended valve types: Flanged swing check valve, tilting disc check valve, metal-seal wafer dual-plate check valve

Advantage: Balances cost and pressure resistance, the most widely adopted rating for industrial general gas service

Class 600 (PN100, Max allowable working pressure 100 bar / 1000 psi ambient)

Typical working pressure: 25–64 bar

Applicable pipelines:

Gas compressor station discharge pipelines

CNG filling station primary pipelines

Medium-high pressure petrochemical process gas (methane, hydrogen, syngas)

Recommended valve types: API 6D swing check valve, lift silent check valve, fully welded dual-plate check valve (hard metal sealing)

Special requirement: For sulfur-containing natural gas, select NACE MR0175 anti-sulfur material to avoid stress corrosion cracking

Class 900 / 1500 / 2500 (PN160–PN420)

Typical working pressure: Above 64 bar, up to 42 MPa

Applicable pipelines: Long-distance high-pressure natural gas transmission trunk lines, LNG receiving station high-pressure pipelines, underground gas storage facilities

Valve standard: Strictly API 6D full-welded forged steel check valve, metal-to-metal hard seal, full body hydrostatic test at 1.5× rated pressure

2. PN Metric Pressure Rating Matching (European / Domestic Standard)

PN10 / PN16: Low-pressure city gas branch pipes (≤10 bar), equivalent to Class150

PN25 / PN40: Medium-pressure urban gas main, factory fuel gas lines, equivalent to Class300

PN63 / PN100: Compressor outlet, CNG medium-high pressure pipelines, equivalent to Class600

PN160–PN420: Long-distance high-pressure gas transmission trunk pipelines

3. Extra Critical Selection Factors for Gas Check Valve Pressure Grade

Temperature derating correction

Valve allowable working pressure drops when gas temperature rises above ambient per ASME B16.34. For high-temperature flue gas or hot process gas, upgrade one pressure class higher for safety margin.

Gas medium corrosion risk

H₂S-containing sour natural gas cannot use low-pressure cast iron Class150 valves; minimum Class300 forged carbon steel (A105) with anti-sulfur treatment is mandatory.

Sealing grade matching pressure class

Class150 low-pressure gas: Soft seat (PTFE / NBR), ANSI Class VI bubble-tight seal

Class300 & above medium/high pressure gas: Metal hard seal (Stellite overlay), ANSI Class IV or V leakage standard

Pressure surge safety margin

Gas pipelines generate larger transient pressure spikes than water pipes during pump/compressor shutdown. Never match valve rating equal to working pressure directly; reserve at least 25% extra pressure capacity.

Conclusion

For low-pressure urban domestic gas pipelines, Class150 (PN16) check valves meet demand. Medium-pressure industrial and municipal transmission gas systems adopt Class300 (PN40) as the mainstream choice. Compressor outlets, CNG pipelines and high-pressure process gas require Class600 (PN100) or higher heavy-duty API standard check valves. High-pressure long-distance gas transmission trunks must select Class900 and above fully welded forged steel check valves, with pressure rating leaving sufficient surge buffer margin.

APA 7th Edition 

Liu, B., & Zhang, H. (2025). Pressure rating selection and safety specification of non-return valves for natural gas and industrial gas transmission pipelines. Journal of Oil & Gas Pipeline Engineering, 23(2), 92–110. 

MLA 9th Edition 

Liu, Bo, and Hao Zhang. “Pressure Rating Selection and Safety Specification of Non-Return Valves for Natural Gas and Industrial Gas Transmission Pipelines.” Journal of Oil & Gas Pipeline Engineering, vol. 23, no. 2, 2025, pp. 92–110. Google Scholar, 

GB/T 7714-2015

[1] LIU B, ZHANG H. Pressure rating selection and safety specification of non-return valves for natural gas and industrial gas transmission pipelines[J]. Journal of Oil & Gas Pipeline Engineering, 2025, 23(2): 92-110.