Lip-seal for body seal (Trunnion 3 piecies ball valve)

[Andresmrj]

I have been facing problems with 10in 2500# trunnion ball valve with unacceptable external process fluid leakage. The reason was the lip-seal that seals between body parts. In fact there is no visual indication of gap extrusion and it looks like it collapse in the opposite pressure direction. Has anyone faced similar situation?

 

[PeterIgg]

Lip seals are very finicky and have all sorts of issues, often associated with the assembly process and good design (or rather lack of). A bit more information would assist: lip seal material; drawing of arrangement; photo of the failure. The first thing I would look at is the surface finish on the sealing surfaces and gap dimensions and if there is any indication of damage on assembly. IMO you need a N4 finish or better and if you are sealing on carbon steel that won't last long if there is any moisture and oxygen around.

 

[gerhardl]

...what about the fluid you are handling? Gas, liquid, mixture, temperature, pressure, residents, additives, abrasive (unclean) fluid, operational cycles, occasional empty pipeline, cleaning process/fluid, earlier repair.

More likely a failure from one of the reasons above, but could also be direct mechanical fault from fabrication, or false (unsupported or given leveraged forces) mounted valve.

 

[Null Full]

The collapse of the lip-seal in the opposite pressure direction, despite no visible gap extrusion, suggests that the current sealing solution may not be optimal for the high-pressure conditions of a 2500# class valve. This is a common issue in demanding applications where traditional elastomeric or polymer seals can struggle to maintain their integrity.
If you're interested in exploring alternative sealing options, please feel free to reach out. We'd be glad to provide more information or arrange a consultation to discuss how we might be able to help improve the performance and reliability of your valve system.

Sonkit
Product Manager at Sonkit Industry, For Metal Ring Seal Solution,

https://sonkitsealing.com/