Problems with graphite gaskets on container manholes.
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Question from a beginner: During recent maintenance work, I encountered a container with a pressure of around 1.0 MPa and a temperature of approximately 80 degrees Celsius. The manhole seal ring has dimensions of Ф560mm*500mm. Since the original graphite gasket has broken apart, I’m wondering how to select a graphite gasket of the appropriate specifications – are there any standards for this? Also, when sealing the manhole, is it usual to tighten the four bolts first and then just tighten them casually?
The specifications have been provided, but it is recommended that the width of the gasket be around 20 mm. There are various standards for manufacturing requirements; for example, the HG20608 standard for graphite composite gaskets can be referred to. When sealing the access holes, the bolts should be tightened symmetrically and evenly, so that the load on each bolt is roughly equal, rather than being tightened arbitrarily