How to overhaul the mechanical seal

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After a long-term operation of the mechanical seal, it is necessary to replace or repair the mechanical seal components to achieve the purpose of reuse.

After a long-term operation of the mechanical seal, the end faces of the moving ring and the static ring are worn due to friction, the spring and the shaft sleeve will also be rusted or damaged, and the sealing ring will lose elasticity due to aging and deformation. All these reasons will cause the mechanical seal to leak. Therefore, after a long period of operation of the mechanical seal, the mechanical seal components need to be replaced or repaired to achieve the purpose of reuse.

Mechanical seal

1. Grinding of the end faces of the moving ring and the static ring

After the moving ring is removed, it is ground, rough grinding first, then fine grinding, and polishing can be carried out if conditions permit. When rough grinding, use 80-160# grit abrasives, and the first grind to remove processing marks. Then it can be used for fine grinding with abrasives above 160# to make the finish meet the design requirements. Carbide or ceramic moving rings need to be polished with a polishing machine after fine grinding. The strength of the polishing machine can be selected from M28-M5 boron carbide. A mirror finish is achieved after polishing. The ceramic ring can be polished with chrome oxide after fine grinding with M5 agate powder.

The static ring of graphite-filled PTFE can be ground with kerosene, gasoline, or water due to its soft material, without adding abrasives. It can also be self-developed during the running-in process, so the finish requirements are not too high.

The grinding method can be ground on a grinding machine if there is a grinding machine, and a figure-8 manual grinding method can be used on the flat glass without a grinding machine.

2. Sleeve inspection

After overhauling and dismantling the shaft sleeve, check the rust and wear. If the rust or wear is relatively slight, it can be polished with fine sandpaper and reused. If the rust or wear is serious, the method of electroplating after processing or a new shaft sleeve can be used.

3. Sealing ring

After a period of use, the sealing ring loses elasticity or ages in most cases and generally needs to be replaced with a new ring.

4. Spring

If the spring is not seriously corroded and can maintain its original elasticity, it is not necessary to replace it. If the corrosion is severe or the elasticity is greatly reduced, a new spring needs to be replaced.

For mechanical seals with assembled boxes, clean the box and inspect the grooves for wear or deformation for corrective repair, re-grooving, or replacement.

After the mechanical sealing element is repaired, it is reassembled, and the pressure test is also carried out after assembly, and then put into normal operation.

The above describes how to overhaul the mechanical seal, and I hope it will be helpful to everyone. Akman Seals is a retailer of mechanical seals. The products sold are of guaranteed quality and reasonable price, which are worth choosing. If you are interested in mechanical seals, you can pay attention to our website.