Hi there, we have experienced a ste

[Julinios]

Hi there, we have experienced a steam gasket leak, the working pressure is 32.5 Barg, after steam turbine trip reaches 39.7 Barg, the temperature is 565 C, the gasket 16" 900# spiral seal Wound Gasket.

https://www.youtube.com/watch?v=HuY_gcIZqcE.

At the moment we have water drops from the pipe.
We did not dissambled yet, the power plant is still running, we need to do the investigation report, We would like to find the root cause analysis.
Please advise.

 

[Tmoose]

First I'd confirm the bolts were torque correctly. First I'd check what the erector's millwrights' work orders call for.
It probably Would not be allowed to tighten the fasteners with the plant running.


Flange faces need the correct surface finish.
Is the leak at one small location on the edge of the gasket?
If the flange face was machined with a spiral finish that did not conform to the appropriate standard for roughness, or using a tool with too small nose radius I envision a leak emerging at one ssmall ocation on the gasket OD.

https://www.apiint.com/resource-center/how-to-choose-flange-facing-finish/

Flange misalignment and pipe strain can impede good sealing.