08/04/2026
Lip Seal Design in Large Diameter Trunnion Ball Valves – Not as simple as it sounds
When dealing with 36" Class 600 Trunnion Mounted Ball Valves, sealing integrity becomes a different game altogether.
A lip seal design is often selected for critical service due to:
✔️ Enhanced sealing performance under both low and high differential pressures
✔️ Self-energizing effect — improves sealing performance as pressure increases
✔️ Better adaptability to thermal expansion and pressure fluctuations
However, executing this design at large sizes comes with real challenges:
▪️ Precision machining of seal grooves — even minor deviations impact sealing performance
▪️ Material behaviour — especially with Duplex internals, where hardness and corrosion resistance must be balanced with sealing flexibility
▪️ Assembly tolerances — ensuring uniform contact across a 36" sealing surface is no small feat
▪️ Testing & validation — achieving consistent zero leakage (API 598 / ISO 5208 Rate A) requires tight control at every stage
This is where design meets manufacturing discipline.
🚀 Project Highlight
Check out the first lot of large-sized valves completed:
▪️ 36" Class 600 Trunnion Mounted Ball Valves
▪️ Duplex internals with special lip seal design
▪️ Engineered for high reliability in demanding service
These valves are now headed to a major end user in the Middle East, marking another milestone for the team.
At JC Valves Middle East, it’s not just about size — it’s about delivering performance where it matters most.