Shim expiration date

It is replaced only when there is maintenance work or a leak; as for gaskets, their replacement depends on the length of time they have been in use, with no concept of regular replacement.

As long as it’s not broken or leaking, keep using it

The stainless steel flanges on the stainless steel pipes in our factory are severely corroded (the metal layer there is almost gone), but this was only discovered after the leaks were found and the pipes were taken apart.

There is no such regulation; it is only replaced when a leak is detected during maintenance

Based on our experience: asbestos rubber generally lasts one year； Rubber gaskets such as polytetrafluoroethylene tend to age over 1 to 2 years ； Metal-wound, flexible graphite, and metal types have relatively stable materials; if there is no leakage during installation, they can be used for a long time. However, once they are removed, they must be replaced because they have suffered some degree of deformation, and it becomes difficult to ensure a proper seal when reinstalling them. The replacement cycle for gaskets should be determined based on the production characteristics. For devices that require maintenance once a year, it’s relatively simple – most gaskets are replaced before they become ineffective. For devices and equipment that operate over long periods of time, it is essential to use gaskets with stable material properties. Regular inspections and replacements should be carried out when the appropriate time comes; one must not wait until leakage occurs before making replacements, as this could lead to serious problems. I saw in a factory a worker who was trying to open a valve while the machine was running, and a stream of hot fluid shot at him, causing severe injuries – the reason for this was the failure of the valve gasket. In addition, leaks and losses from temporary stops also amount to a significant amount.

Floor 6 explained it in detail, but we usually replace it only when it breaks.