Mechanical seal leakage, O-ring

The PTFE gasket is in contact with the material and serves to prevent corrosion, while the O-ring is used for sealing; therefore, it should be the PTFE gasket that is placed on top of the O-ring~~~

The O-ring generally makes contact with the metal to create a radial seal, while the PTFE gasket should be on the other side.

This post was last edited by lizhi3296 on 2015-7-3 09:13. PTFE gaskets are used to prevent the O-rings from being squeezed out, so PTFE should be placed on the low-pressure side. As long as the high and low pressure sides are distinguished, the PTFE gasket will not be placed in the wrong location.

Haha, I’m really good at training apprentices. First, it’s important to understand one thing: mechanical seals are designed to prevent leakage outward; of course, there’s no issue with leakage inward. There are three areas where leakage can occur at the mechanical seal: First, the gap between the stationary ring and the volute; this issue is resolved by using a sealing ring for the stationary ring. Second, the gap between the stationary ring and the rotating ring; this is addressed through relative movement of the two rings with high surface finish (smooth sealing surfaces), with frictional heat being carried away by the fluid. Third, the gap between the rotating ring and the pump shaft; this is resolved by using a sealing ring for the rotating ring. Therefore, this sealing ring must make close contact with the pump shaft/rotating ring, and no other elements are allowed to get in the way

The 5th floor is correct. The function of the PTFE gasket is to prevent the O-ring from being compressed and forced into the gaps between metal components, which could cause permanent deformation of the O-ring and lead to seal failure

The O-ring is located on the side close to the moving ring, while the PTFE gasket is behind the O-ring

Two additional points: First, every mechanical seal has some leakage, but the normal amount of leakage is very small. The leakage direction of the single-face mechanical seal is outward ； In pressure-free double-end face mechanical seals, the leakage direction of both the inner and outer seals is outward ； In a pressure-bearing double-seal design, the leakage direction of the inner seal is inward, while that of the outer seal is outward. II. The three leakage points you mentioned apply to bulk-type machine seals; for packaged machine seals, there are five leakage points – the area between the shaft sleeve and the shaft, as well as the area between the end cover and the equipment housing, are also leakage points