Criteria for Replacing Sealing Gaskets of Cracking Reactors

Criteria for Replacing Sealing Gaskets of Cracking Reactors

Sealing gaskets (mainly for reactor doors and flanges) are vulnerable parts of batch-type cracking reactors. Replace them immediately if any of the following phenomena occur, without waiting for a fixed cycle. The judgment is mainly based on four dimensions: intuitive leakage, appearance damage, service life, and process abnormality, adapted to the service characteristics of high-temperature sealing:

Medium leakage (the most direct criterion)

During heating/pressure holding, oil dripping, oil-gas leakage occurs at the sealing of reactor doors and flanges, or obvious pyrolysis oil-gas odor is detected on site. Even slight air leakage requires replacement to avoid pressure loss and potential safety hazards.

Physical damage to appearance

Check after shutdown and cooling: if the gasket is cracked, deformed, hardened, aged and brittle, partially damaged, dented on the sealing surface, or melted and adhered to the reactor body/flange at high temperature, it will lose elasticity and fail to seal.

Expired service life / reaching maintenance frequency

For high-temperature resistant sealing gaskets (mainly fluororubber/graphite materials), under the high-temperature (300-500℃) working condition of cracking reactors, after continuous use for 1-3 months / 20-30 production batches, preventive replacement is recommended even without obvious damage (can be shortened to within 1 month for high-load production).

Abnormal process operation

When there is no other fault, the reactor has difficulty in pressure holding, rapid pressure drop, or a sudden drop in heating efficiency. If it is confirmed that the poor sealing at the sealing part is the cause after troubleshooting, replace the gasket immediately.

Supplementary Notes

When replacing, check synchronously whether the sealing surfaces of the reactor body and flange are flat and free of scratches/corrosion. If the sealing surface is damaged, repair it first, otherwise the new gasket will still leak;

Gaskets of different materials have different applicable service lives: graphite composite gaskets have stronger adaptability with a service life of about 2-3 months; fluororubber gaskets have a service life of about 1-2 months. The replacement frequency shall be adjusted according to the actual material used.