Trunnion DBB Ball Valve
Trunnion DBB Ball Valve is selected for larger sizes or higher pressure classes where a trunnion-supported dbb arrangement is required. A trunnion DBB ball valve applies fixed ball support to a double block and bleed arrangement. It is considered when size, pressure class or operating torque makes a floating DBB architecture less suitable. Seat arrangement, cavity relief and bleed connection must be aligned with the isolation philosophy.
Trunnion DBB Ball Valve for industrial valve projects.
A trunnion DBB ball valve applies fixed ball support to a double block and bleed arrangement. It is considered when size, pressure class or operating torque makes a floating DBB architecture less suitable. Seat arrangement, cavity relief and bleed connection must be aligned with the isolation philosophy.
When to select this design
Larger sizes or higher pressure classes where a trunnion-supported DBB arrangement is required.
Choose trunnion DBB when size or pressure requires trunnion support and the project also requires double isolation and bleed.
Typical applications
- High-pressure pipelines
- Gas transmission
- Compressor stations
- Large-bore isolation
Trunnion DBB 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 | Trunnion support is used in a DBB architecture for larger sizes or higher pressures. The fixed ball support reduces the effect of line pressure on operating torque compared with a floating arrangement at similar duty. |
|---|---|
| Seat & sealing | SPE/DPE selection, cavity relief and the definition of DBB versus DIB are critical. The project must state the required sealing directions rather than relying on the term DBB alone. |
| End connection | RF, RTJ or butt-weld ends can be specified according to class and piping layout. High-pressure DBB projects often require careful face-to-face and bleed-connection coordination. |
| Engineering focus | Review seat loads, cavity pressure, actuator torque and isolation sequence together. High class service can make vent/bleed sizing and safe depressurization especially important. |
| Material selection | Cast or forged bodies, low-temperature materials, stainless or duplex trim may be used depending on service. Material selection should follow the same rigor as the mainline pipeline valves around the DBB. |
| Testing & inspection | Test both isolation functions and bleed cavity behavior to the project procedure. Fire-safe, emission, NDE/PMI and high-pressure inspection requirements may also apply. |
Engineering considerations for Trunnion DBB Ball Valve.
Construction and maintenance
Trunnion support is used in a DBB architecture for larger sizes or higher pressures. The fixed ball support reduces the effect of line pressure on operating torque compared with a floating arrangement at similar duty.
Seat, sealing and torque
SPE/DPE selection, cavity relief and the definition of DBB versus DIB are critical. The project must state the required sealing directions rather than relying on the term DBB alone.
Piping and installation
RF, RTJ or butt-weld ends can be specified according to class and piping layout. High-pressure DBB projects often require careful face-to-face and bleed-connection coordination.
What to verify before approving the technical offer.
Engineering risk
Review seat loads, cavity pressure, actuator torque and isolation sequence together. High class service can make vent/bleed sizing and safe depressurization especially important.
Materials and traceability
Cast or forged bodies, low-temperature materials, stainless or duplex trim may be used depending on service. Material selection should follow the same rigor as the mainline pipeline valves around the DBB.
Inspection and testing
Test both isolation functions and bleed cavity behavior to the project procedure. Fire-safe, emission, NDE/PMI and high-pressure inspection requirements may also apply.
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 Double Block & Bleed Valves configurations.
Compare related designs by construction, pressure class, temperature range and service conditions.
Choose integral DBB when space, weight and reduction of external joints are the primary objectives.
Compare Integral DBB Ball Valve →Choose double-ball DBB when the isolation philosophy specifically calls for two separate ball closure elements.
Compare Double Ball DBB Valve →Choose instrument DBB when the isolation duty is for small-bore instrument connections rather than the main pipeline.
Compare Instrument DBB Valve →Return to the Double Block & Bleed Valves range to compare all configurations.
Back to Double Block & Bleed Valves Range →Continue the technical selection.
Use these pages to check pressure class, material, standard and end-connection requirements against this valve design.
Trunnion DBB Ball Valve FAQ
What is a trunnion DBB ball valve?
A trunnion DBB ball valve applies fixed ball support to a double block and bleed arrangement. It is considered when size, pressure class or operating torque makes a floating DBB architecture less suitable. Seat arrangement, cavity relief and bleed connection must be aligned with the isolation philosophy.
Where is a trunnion DBB ball valve commonly used?
Typical applications include High-pressure pipelines, Gas transmission, Compressor stations, Large-bore isolation. Final suitability depends on the actual service medium, pressure, temperature and project specification.
What information is needed to quote a trunnion DBB 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 trunnion DBB ball valve different from other double block and bleed valve designs?
Choose trunnion DBB when size or pressure requires trunnion support and the project also requires double isolation and bleed.
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.