2.1 Onshore oil and gas extraction (wellhead and gathering)

Valve requirements: Christmas tree valves (gate valves, needle valves), throttle valves, emergency shut-off valves.

Technical challenges: resistance to sulfide stress corrosion cracking (SSCC) in high-sulfur (H₂S) environments, and high pressure (70-140MPa).

Typical applications: wellhead main control valve, water injection well regulating valve, gas gathering station separator shut-off valve.

2.2 Long-distance natural gas pipelines

Valve requirements: fully welded ball valve, plug valve, emergency shutdown valve (ESDV).

Technical challenges: large diameter (DN1000+), high pressure (10-12MPa), remote monitoring in uninhabited areas, and SIL3 safety integrity.

Typical applications: compressor station inlets and outlets, off-take branch line shutoffs, and line block valve stations.

2.3 Oil refining and petrochemical industry

Valve requirements: hydrocracking gate valve, catalytic cracking slide valve, reforming control valve.

Technical challenges: hydrogen-exposed conditions (hydrogen embrittlement protection), high-temperature sulfur corrosion, and catalyst particle wear.

Typical applications: high-pressure separator in hydrogenation unit, flue of catalytic cracking regenerator, hydraulic decoking valve in delayed coking unit.

2.4 LNG receiving terminal and liquefaction plant

Valve requirements: ultra-low temperature ball valve, butterfly valve, check valve (-196℃).

Technical challenges: maintaining toughness of cryogenic materials (austenitic stainless steel/aluminum alloy), and preventing leakage (wide explosion limit of LNG).

Typical applications: LNG tank inlet and outlet, shut-off before vaporizer, loading skid control valve.