Negative pressure equipment sealing
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Our factory has several negative pressure devices; initially, asbestos gaskets were used, but they did not provide adequate sealing. Later, high-strength graphite gaskets were tried, yet the sealing effect remained poor. Does anyone have any better sealing methods?
What kind of sealing does the original poster mean? Also, the medium used, temperature, and operating conditions are not clear, making it difficult to answer
The original poster should specify where it is to be used; since it relates to vacuum level, rubber seals are generally sufficient, and they need to be replaced every six months
Used for equipment flanges, with a diameter of 1500 mm; relatively difficult to replace
Specify the temperature and pressure, as well as whether oil is allowed. If oil is not prohibited and the temperature is not high, butter or molybdenum disulfide can be applied to the sealing surface for sealing, which will last at least half a year.
The first choice is an expanded PTFE gasket. The downside is that it’s expensive; the second choice is a stone tomb wrapping mat. The downside is that it’s not as good as PTFE
I have encountered the situation mentioned by the original poster; it’s probably similar to the working conditions you described. We are vacuum evaporation equipment, and the head flanges are roughly the same size. Using PTFE gaskets is certainly an option, but they are expensive. During use, silicone gaskets can be used; having them custom-made is also costly. It is recommended that the poster consider using PTFE gaskets, and be sure to tighten the screws regularly. If the temperature is not high, silicone gaskets or heat- and acid-resistant rubber gaskets can be considered; buttery packers are also an option. It should be able to solve the original poster’s problem.