Analysis of the causes of leakage in double-end face mechanical seals

This post was last edited by foam_ZPTK on 2018-1-20 08:24. Based on the pump model, it seems to be ZE40-315; as for the color, it doesn’t appear to be PTFE. If there is a transparent ring-like layer on the outside of the O-ring, then that is PFA – a copolymer of a small amount of perfluoropropylperfluoroethylene ether and polytetrafluoroethylene. Looking at your last image, the sealing ring surface has been abraded through dry friction.

Looking at the second diagram, the swelling of the O-ring is quite severe~~~ It is recommended to replace it~~~

This post was last edited by wei604213406 on 2018-1-20 at 18:21. The rise in the liquid level in the seal oil tank is probably caused by the failure of the front-end plan11 machine seal; it should be checked carefully, as rubber expands when heated and contracts when cooled. Is the stator ring in Figure 4 located at the front end or near the motor side? What causes the severe damage at the stator ring’s auxiliary sealing area? Turning down the flushing fluid clearly causes wear on the rear end seal

The material of the O-ring on the stationary ring on the medium side is not suitable; change the material. Alternatively, try wrapping a layer of PTFE tape around the intact O-ring of the stationary ring! The static ring on the non-media side suffers damage due to contamination of the isolation fluid by the medium, as there is no circulation of this isolation fluid!

Pump model: HZE80-40-315

Based solely on the photos of the mechanical seal, the poster can consider the following aspects: 1. The mechanical seal ring does not seem to be a PTFE ring as mentioned by the original poster; it’s possible that PTFE is used on the side in contact with the medium, while the ring on the atmospheric side exhibits swelling. It is recommended to replace the sealing rings – they can all be replaced with PTFE rings, or with rings covered in plastic. If the original poster doesn’t mind spending extra money, PTFE rings can be considered as an option. It seems there is dry grinding on the surface, but I think it’s due to excessive compression or too much spring force; it is recommended to check whether the shaft is shifting and whether the operating height of the mechanical seal is correct. 3. The sealing ring in the first image is likely due to the thermal deformation of the ring, 4. This pump is not large, so it is recommended to use a solid ring rather than an inset ring. This should be a clone of the C8B type mechanical seal; the static ring is of the BP type, which is a standard version. The overall silicon carbide component should not be difficult to obtain

It is recommended that the poster consider: 1. The sealing ring does not seem to be a PTFE ring as the original poster mentioned; it is a rubber sealing ring 2. In Figure 2, the sealing ring is a rubber ring; it appears to have been deformed due to heat. It is possible to consider whether the compression amount of the mechanical seal is too large, whether the spring force is excessive, and whether the shaft is moving erratically. It is recommended to consider PTFE material seals, or seals made of coated materials; if the person in question has enough money, perfluoropolymer seals could be an option. It is recommended that the poster avoid using fitted rings and opt for integral rings. According to the diagram, it should be a Clone C8B type mechanical seal, which should be easy to obtain. In the last image, the wear on the mating surfaces is quite severe; please consider whether this is due to dry friction or abnormal compression of the mechanical seal

It is recommended that the poster consider: 1. The sealing ring does not seem to be a PTFE ring as the original poster mentioned; it is a rubber sealing ring 2. In Figure 2, the sealing ring is a rubber ring; it appears to have been deformed due to heat. It is possible to consider whether the compression amount of the mechanical seal is too large, whether the spring force is excessive, and whether the shaft is moving erratically. It is recommended to consider PTFE material seals, or seals made of coated materials; if the person in question has enough money, perfluoropolymer seals could be an option. It is recommended that the poster avoid using fitted rings and opt for integral rings. According to the diagram, it should be a Clone C8B type mechanical seal, which should be easy to obtain. In the last image, the wear on the mating surfaces is quite severe; please consider whether this is due to dry friction or abnormal compression of the mechanical seal