Fully Welded Trunnion Ball Valve
Fully Welded Trunnion Ball Valve is selected for transmission and pipeline isolation where a welded pressure shell and trunnion-supported ball are preferred. A fully welded trunnion ball valve combines fixed ball support with a permanently welded body shell. This construction reduces external body flange joints and is commonly selected for gas transmission and long-distance pipeline service. End connections may be flanged or butt-weld depending on project design.
Fully Welded Trunnion Ball Valve for industrial valve projects.
A fully welded trunnion ball valve combines fixed ball support with a permanently welded body shell. This construction reduces external body flange joints and is commonly selected for gas transmission and long-distance pipeline service. End connections may be flanged or butt-weld depending on project design.
When to select this design
Transmission and pipeline isolation where a welded pressure shell and trunnion-supported ball are preferred.
Choose this design when long-term pressure-shell integrity and reduced body joints are stronger priorities than body disassembly.
Typical applications
- Gas transmission
- Long-distance pipelines
- Pipeline stations
- Buried installations
Fully Welded Trunnion Ball Valve: design points to confirm.
This is a specific valve construction. Final size, class, material and seat combinations depend on the approved datasheet and design calculation.
| Body construction | The pressure shell is permanently welded instead of using bolted body joints. The ball is trunnion supported and the design is intended for long-term pipeline service where reducing external body-joint leak paths is valuable. |
|---|---|
| Seat & sealing | SPE or DPE seat systems may be used depending on pipeline isolation philosophy. Cavity pressure relief and drain/vent arrangements should be defined before welding the final body assembly. |
| End connection | Butt-weld ends are common, while flanged ends may also be used in station service. Weld-end dimensions and field welding requirements must match the pipeline specification. |
| Engineering focus | Because the body is not intended for routine disassembly, seat/stem reliability, corrosion protection and long-term maintenance philosophy deserve early review. Full bore may be required for piggable pipelines. |
| Material selection | Carbon steel or low-temperature steel body materials are common project choices; trim and seals depend on media and temperature. Weld procedure and material traceability are key manufacturing controls. |
| Testing & inspection | Pressure testing, weld NDE, dimensional inspection, coating and final functional testing should be completed before release. Field-weld protection requirements should be coordinated with the coating system. |
Engineering considerations for Fully Welded Trunnion Ball Valve.
Construction and maintenance
The pressure shell is permanently welded instead of using bolted body joints. The ball is trunnion supported and the design is intended for long-term pipeline service where reducing external body-joint leak paths is valuable.
Seat, sealing and torque
SPE or DPE seat systems may be used depending on pipeline isolation philosophy. Cavity pressure relief and drain/vent arrangements should be defined before welding the final body assembly.
Piping and installation
Butt-weld ends are common, while flanged ends may also be used in station service. Weld-end dimensions and field welding requirements must match the pipeline specification.
What to verify before approving the technical offer.
Engineering risk
Because the body is not intended for routine disassembly, seat/stem reliability, corrosion protection and long-term maintenance philosophy deserve early review. Full bore may be required for piggable pipelines.
Materials and traceability
Carbon steel or low-temperature steel body materials are common project choices; trim and seals depend on media and temperature. Weld procedure and material traceability are key manufacturing controls.
Inspection and testing
Pressure testing, weld NDE, dimensional inspection, coating and final functional testing should be completed before release. Field-weld protection requirements should be coordinated with the coating system.
Send the valve datasheet together with the piping class and project valve, material, testing and coating specifications. Missing design inputs should be clarified rather than assumed.
Other Fully Welded Ball Valves configurations.
Compare related designs by construction, pressure class, temperature range and service conditions.
Choose this design when the valve body remains buried and the operator interface must be brought above grade.
Compare Underground Fully Welded Ball Valve →Choose this configuration when the application is specifically gas transmission rather than general industrial welded-body service.
Compare Gas Pipeline Fully Welded Ball Valve →Return to the Fully Welded Ball Valves range to compare all configurations.
Back to Fully Welded Ball Valves Range →Continue the technical selection.
Use these pages to check pressure class, material, standard and end-connection requirements against this valve design.
Fully Welded Trunnion Ball Valve FAQ
What is a fully welded trunnion ball valve?
A fully welded trunnion ball valve combines fixed ball support with a permanently welded body shell. This construction reduces external body flange joints and is commonly selected for gas transmission and long-distance pipeline service. End connections may be flanged or butt-weld depending on project design.
Where is a fully welded trunnion ball valve commonly used?
Typical applications include Gas transmission, Long-distance pipelines, Pipeline stations, Buried installations. Final suitability depends on the actual service medium, pressure, temperature and project specification.
What information is needed to quote a fully welded trunnion ball valve?
Provide size, quantity, pressure class, body and trim materials, seat material, end connection, design pressure and temperature, media, operation, design standard, fire-safe/emission requirements, testing, coating and documentation scope.
How is a fully welded trunnion ball valve different from other fully welded ball valve designs?
Choose this design when long-term pressure-shell integrity and reduced body joints are stronger priorities than body disassembly.
Technical documents for project review.
For technical evaluation, request the applicable product documents and inspection records for the offered valve configuration.
Product Photos
Additional finished-valve, nameplate and component photos are available for the selected valve configuration.
GA Drawing / Datasheet
GA drawings and datasheets are prepared for the selected size, pressure class and valve configuration.
Testing & Inspection Records
Inspection documentation can include pressure testing, dimensional inspection, PMI, NDE/NDT and coating records as required by the project.