Those who frequently interact with industrial flanges understand that the sealing requirements for flanges are very high. This is because the interior of flanges typically houses bearings, which are generally not easily disassembled during operation. Therefore, metal spiral wound gaskets play a crucial role. If the sealing performance is poor, the grease or other oil and gas inside may leak or dry out.

In traditional industrial equipment, before the advent of metal spiral wound gaskets, most companies typically used parchment paper gaskets or none at all. For instance, in ordinary locomotive manufacturing factories, metal spiral wound gasket manufacturers emphasized the necessity of using parchment paper gaskets between the bearing seat of the transmission wheelset and the flange. The fundamental reason is that parchment paper gaskets are easy to manufacture and are inexpensive.

However, parchment paper gaskets have a relatively short lifespan. When used to seal grease, the grease typically dries out within a year or so. Generally, locomotive manufacturing factories choose to perform comprehensive maintenance, which involves re-applying grease, approximately once a year. Although metal spiral wound gaskets with inner rings are now available, many locomotive experts still use parchment paper gaskets or none at all, primarily to save costs.

Perhaps it is temporarily feasible to use paper gaskets or no gaskets at all on the bearing seat and flange of locomotives, and there may not be any immediate issues. However, after prolonged use, maintenance and oil refill will still be necessary. But can the same be said for fields with higher sealing requirements? For example, can we avoid using metal spiral wound gaskets with outer rings in the petrochemical industry?

Naturally, the answer is no. It's important to remember that many oil leakage accidents are caused by issues with flanges, but the key source of leakage problems often lies in the metal spiral wound gaskets inside. Therefore, the use of metal spiral wound gaskets is also essential for flanges in power plants, ships, and pressure vessels.