NDT to check gasket in RTJ flange

[MadieKerang]

HIiiiiii....

Anybody ever used successful NDE technique to check the gasket in the RTJ flange during operation. I have concern if the gasket is CS in the SS piping.Please advice.

 

[unclesyd]

If your are looking for corrosion of the RTJ gasket there isn't any positive way to check it. I don't think a radiograph will show any metal loss on the gasket as the ends of the gaskets will be buried under the flange.

If you are worried about thermal expansion we use CS, really ARMCO Iron, in CS/SS and SS/SS flanges by the dozens.
About the only check we do when using RTJ fittings is check to see if the flange faces are parallel We make and break thousands of this type flange using a new gasket every year.

 

[rustbuster]

Use a magnet to check the material. FYI, UT can be used to check for corrosion, you would need a pencil probe.

 

[ndeguy]

You certainly wouldnt be able to differentiate between CS and SS gaskets in-service by NDE.

As rustbuster wrote, easy once you have broken down the joint.

 

[unclesyd]

Just remember that some rings are from material like 17/4 PH steel and are magnetic.

 

[MadieKerang]

All,

tqvm for the information,really appreiate it... i have request the piping inspector to use CuCuso4 test to check the gasket whether it is CS or not in the SS RTJ flange (large size only), I dont know if this method is working or not since a bit difficult for the spray nozzle to reach the gasket for small size RTJ flange.Another option is to use pencil probe/small size magnetic tool but too difficult to get this kind of tool.

Anyway, I will give a feedback if it is working or not, worth to try it. Thanks

 

[unclesyd]

Why the concern, as CS gaskets will work in SS flanges and SS gaskets work in CS flanges with 99% of the a leaking flange is from poor makeup. If you have a corrosion problem then I could see the reason to check them. I would use a 50/50 vol/vol with water of HNO3 in lieu of the CuSO4 solution as sometimes there is a wax coating on the gasket and CuSO4 will run off.
Unless specifically called out all CS gaskets re ARMCO Iron and with our supplier the SS gaskets are 316 SS, dead soft.

Can you post your specific problem??