Compatibility of Spiral Wound Gasket (SPW) with Flanges having Different Surface Finish

[Awais Arshad]

Hi all,

We have a case where the mating flange has different surface finish compared to the top flange; one flange has a surface finish value of Ra 3.2-6.3 um, while the other has a surface finish value of 1.6 um.

As per my literature research, the SPW gasket works find under such configuration. Still, being a forum of expert engineers, will appreciate if the members can shed light on the case i.e. if a Spiral Wound Gasket will operate or work fine @ DP = 35 kg/cm2g & DT= 220 dC under different flange surface finishes as mentioned earlier.

Regards,
Awais

 

[FacEngrPE]

The only times I have had problems with spiral gaskets sealing the problem was either bad alignment of the flanges or insufficient clamping force. The surface finish is recommended to have roughness in a phonograph pattern, but is otherwise less critical to sealing.
Recommendation is to follow the guidance in the OEM technical manual (see the flexitalic design manual).
If you encounter a situation where the spiral component of the gasket unwinds, consider ordering the gasket with an inner ring.

 

[Awais Arshad]

Thank you for the response. I couldn't catch up in time due to some personal reasons. Inner ring could not be ordered due to geometry constraints. However, we resolved the issue by replicating design of a fellow company having similar geometry and service - upon their consent.