I. Real‑Shot View of Mass‑Produced 3PC Trunnion Ball Valves
These on‑site workshop photos show finished bulk 3‑piece trunnion mounted ball valves ready for delivery. You can clearly observe typical features: three‑piece valve body, brass‑faced flange sealing surface, and gear operator for manual operation.
Different from floating ball valves, the ball of trunnion ball valve is fixed by upper and lower trunnion shafts. Media pressure will not push ball against downstream seat. This mechanical design makes it perfect for large‑size and high‑pressure pipeline services. All valves in picture adopt multi‑hole high‑pressure flanges complying with ASME B16.5 standard, widely used in oil & gas and chemical process projects.
II. What API 6D Standard Specifies for 3PC Trunnion Ball Valves
API 6D is the globally‑recognized specification for pipeline valves in oil and gas industry, acting as basic qualification for pipeline ball valve projects.
1. 3‑Piece Split Body: Consists of left, center and right body segments. Internal ball and seat parts can be serviced without removing full valve from pipeline, greatly cutting maintenance cost.
2. Trunnion‑Supported Ball: Ball weight and hydraulic load are borne by trunnion shafts, not valve seats. Operating torque stays low even under high pressure, covering pressure class from Class150 up to Class2500.
3. Bi‑directional Seat Seal & Auto‑Relief Function: Automatic cavity pressure relief protects valve body from over‑pressure damage caused by trapped fluid inside valve cavity, which is critical for pipeline safety.
4. Material & Mandatory Factory Test: Common body materials include WCB carbon steel, A105 forged steel, CF8M stainless steel. Every valve shall go through API 6D required hydrostatic shell test and seat bubble‑tight sealing test before shipment.
III. Key Manufacturing Details Observed From Workshop Photos
High‑Pressure Flange With Hardened Sealing Face
Multi‑bolt high‑pressure flanges with brass overlay sealing surface resist scratch during pipeline operation, rated per ASME B16.34 pressure‑temperature rating for direct field pipeline connection.
Gear Operator for Manual Operation
Gear box reduces manual operating torque for large high‑pressure trunnion ball valves. It can also be adapted with electric or pneumatic actuators for remote automatic control, flexible for both manual site operation and future automation upgrade.
Strict Assembly Quality Control per API 6D
API 6D valve assembly requires strict internal cleanliness. Any debris inside valve cavity will scratch sealing seats and cause internal leakage. All finished valves pass full‑range performance test to guarantee bubble‑tight shut‑off for long‑term pipeline service.
IV. Typical Application Scenarios for API 6D 3PC Trunnion Ball Valves
1. Oil & gas transmission pipelines and gathering stations
2. High‑pressure chemical process lines
3. Power plant and hydrocarbon storage tank farm
4. Services requiring large‑size, high‑pressure bi‑directional shut‑off
Floating ball valves work well for small‑bore low‑pressure conditions. For size DN100 and above, pressure Class300+, engineers prefer trunnion mounted 3‑piece ball valves meeting full API 6D specification.
V. Sourcing Pitfalls to Avoid
Many 3‑piece ball valves on market look similar in appearance but are NOT built to complete API 6D requirements. When sourcing, verify API 6D certification, full hydro‑test reports, real trunnion ball structure and cavity relief function, do not judge only by “3PC ball valve” product title.
VI. Conclusion
Real workshop photos help us understand that API 6D 3PC trunnion mounted ball valve is safety‑oriented pipeline equipment governed by complete industrial standards, not just mechanical appearance. Every step including body forging, seal selection, assembly procedure and final factory test matters for long‑term pipeline safety. If you are searching for compliant trunnion ball valves for high‑pressure pipeline projects, always check full API 6D manufacturing & test documentation.
CTA：Contact us to get API 6D 3PC trunnion ball valve datasheet and application engineering support.
