Consultation on material selection for drum manway gaskets
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One of the units in our facility is equipped with a steam generator, whose drum at the top operates at a pressure of 3.9 MPa and a temperature of 275°C; the nominal flange pressure is CL600. It has been found that the manway gasket of the steam drum (as shown in the diagram, a wound gasket) is damaged. After analyzing the cause, it was determined that the gasket’s size is slightly larger than that of the steam drum; when the gasket was installed from the outside inward, manual force was applied, causing the gasket to deform and thus enabling its installation. It is possible that this manual deformation led to the damage of the wound gasket. In our facility, some gasket materials used for the manholes of the steam drums are paper foil gaskets (i.e., asbestos rubber gaskets). By referring to the standard \"HG 20635 – Specifications for the Selection of Steel Pipe Flanges, Gaskets, and Fasteners (American System)\", it is clear that the use of paper foil gaskets for the steam drums in our department does not comply with these standards. However, multiple units in our facility have been using paper foil gaskets for their steam drums without any issues. I’m a bit stuck – due to the limitations on the size of the manhole in the steam drum, gasketing materials tend to get damaged during installation, while foil gaskets do not meet the required standards. I would appreciate some advice from those with more experience: which types, materials, and standards of gaskets would be suitable? Thank you! !
1. It is personally recommended to send the flange dimensions to the relevant gasket manufacturers for processing according to the drawings. 2. Sheet gaskets are not recommended for use when the weight is greater than 300 pounds. Many gasket manufacturers are able to handle this type of operating condition.
Use the RSB flexible graphite gasket from the non-metallic gaskets
Generally, for situations like the one you mentioned, a paper asbestos board with a thickness of 3-5 mm is sufficient. This was the material used for the gaskets in steam drums in the past, and it’s completely normal to use it in this way. Before use, a pressure test should be conducted; if there is no leakage, then it’s fine. Now, metal wound gaskets must be used for the waste heat boiler gaskets.
The gasket manufacturer can handle this issue, but due to the size constraints of the steam drum on site, it’s necessary to bend the gasket in some way when installing it, which makes it prone to damage
:Lol, just provide the blueprint to the gasket manufacturer and they can produce it; that’s what we’ll do
The pressure and temperature are both a bit too high; asbestos gaskets should not be used here. There is something wrong with the design of this access hole (an elliptical access hole is generally used in such cases)； Since that’s the case, then use a wound gasket with an inner ring or a flexible graphite gasket
For us users, it really comes down to the usage results – we just choose the one that performs well
Only gaskets made of flexible materials can be used in this area; otherwise, they won’t fit. It is recommended to use XB450 high-pressure asbestos rubber gaskets