Carbon Steel Trunnion Mounted Fully Welded Ball Valve Extended Stem

Fully Welded Carbon Steel Body: The valve body is fully welded from carbon steel or low-alloy steel forgings / steel pipes including ASTM A105, A350 LF2, A694 F52/F65, with no middle body flange and no external bolt connections. It completely eliminates external leakage paths to achieve zero fugitive emission, features a long maintenance-free service life, and matches the service life of buried pipelines.

Trunnion Mounted Design: The ball is fixed in the valve body by upper and lower support shafts. The substantial thrust generated by media pressure is borne by the bearing system, delivering stable and extremely low operating torque. This avoids operational difficulties or seizure of floating ball valves under large-bore and high-pressure conditions, making it especially suitable for buried large-bore high-pressure applications.

Buried Extended Stem: Stem length is customized according to burial depth (typically 500mm–3000mm), placing the operating mechanism above ground level. Equipped with anti-settlement universal joints or expansion joints, it adapts to soil settlement and ground displacement, ensuring long-term operational flexibility.

Full or Reduced Bore Optional: Flow bore diameter can match the pipeline inner diameter (full bore) or be reduced as required. The full bore design allows pig passage, while the reduced bore design reduces weight and cost.

Double Seat Sealing System: Standard double piston effect (DPE) seats provide reliable bi-directional sealing. Single piston effect (SPE) self-relief seats are optional to prevent abnormal cavity overpressure, complying with different safety code requirements.

Fully Welded End Connections: Both ends of the valve body are connected to the pipeline by standard groove butt-welding. Welded joints undergo 100% radiographic inspection to ensure service life matching the pipeline, eliminating leakage risks caused by aging flange gaskets.

Fire-Safe Design: Complies with API 607 / ISO 10497 standards. In fire conditions, metal-to-metal sealing and graphite packing retain sealing performance to prevent leakage of flammable media.

Anti-Static Device: Built-in anti-static spring / steel ball structure ensures electrical continuity between stem and body, ball and body, preventing static accumulation from high-pressure high-velocity flowing media.

Blowout-Proof Stem Design: The stem is equipped with a lower anti-blowout shoulder, preventing stem ejection under abnormal internal overpressure and ensuring operational safety.

Emergency Seal and Grease Injection System: Emergency seal grease injection fittings are standard at seat and stem areas, providing temporary sealing by injecting sealant when sealing is compromised.

Buried Anti-Corrosion System: The valve exterior is coated with three-layer PE/PP or epoxy powder coating, combined with a sacrificial anode cathodic protection system, ensuring long-term resistance to soil corrosion and electrochemical corrosion underground.

Natural Gas Long-Distance Pipelines: Used as core shut-off and isolation valves for cross-national / cross-regional natural gas transmission trunk lines, branch lines, compressor stations, metering and regulating stations, and pigging stations, withstanding high pressure and hydrodynamic pressure.

Crude Oil & Petroleum Product Pipelines: Applied for line isolation, station block valve service, and pig launching / receiving in crude oil and refined product pipelines.

Underground Gas Storage: Suitable for buried high-pressure pipeline systems at injection-production wells, gathering and injection stations, and monitoring wells.

Chemical & Energy Industries: Used in buried or pipe-rack installed pipelines for corrosive and high-temperature high-pressure media.

Zero Fugitive Emission & Long Service Life: Fully welded structure completely removes external leakage points, eliminating gasket aging and bolt loosening. Designed service life is 30–50 years, matching buried pipelines, greatly reducing life-cycle costs.

Reliable Performance at High Pressure & Large Bore: Trunnion mounted design transfers high media thrust to the bearing system, enabling controllable operating torque and stable opening / closing even in large-bore high-pressure conditions, avoiding seizure risks.

Multiple Safety Guarantees: Fire-safe, anti-static, blowout-proof stem, cavity relief, emergency grease injection, DBB / DIB functions provide layered protection, complying with the strictest safety codes for oil and gas pipelines.

Comprehensive Anti-Corrosion System: Dual protection of three-layer PE/PP coating plus sacrificial anode cathodic protection adapts to various soil corrosive environments, ensuring safe long-term underground operation.

International Standard Certifications: Complies with global pipeline valve standards including API 6D and ISO 14313, with monogram certification and SIL 3 certification, meeting procurement requirements for international long-distance pipeline projects.