expansion joint failure

[soupsamich]

We have recently had some failures on EPDM expansion joints in Hot water systems. We are running below rated temp and pressure for the joint, and are still seeing failures. I have talked to some other companies about this and they too have had this experience. Does anyone out there have similar experiences or suggestions? It appears as if we will be going to metal bellows type to replace all installed.

 

[langahl]

soupsamich,
First you may need to check that the expansion joints were properly installed; alignment as well as spacing between pipes. This will ensure stress free expansion joints. Secondly check for compatibility with the atmosphere and operating conditions in which the joint functions.

That should get you started.
langahl

 

[soupsamich]

Let me add a little more info. We have checked allignment and chemical compatibility. The expansion joint was installed per manufacturers recommentations. Pending 3rd party it appears as if there are heat cracks in the rubber/EPDM.

 

[TBP]

The only instances where I have seen cracks in this kind of material (gaskets, o-rings, etc.) is from exposure to temperatures over the rating, or chemical attack. It wouldn't be the first time that a manufacturer cut one too many corners in an effort to be "low bid".