Contact Us
Fax: +86-510-85917799
Address: No.18 Longdan road, Hu Dai Industrial Park, Binhu district, Wuxi, Jiangsu province, China
Home > Knowledge > Content
Stress relaxation of rubber gaskets for plate heat exchangers
Sep 17, 2020

Gasket is an important part of plate heat exchanger, which plays a key role in the operation of plate exchanger. Stress relaxation is an important factor limiting the service life of rubber gasket for plate changer. Therefore, we need to have a certain understanding of the stress relaxation of rubber gaskets:


The sealing operation of plate heat exchanger depends on the comparison between the instantaneous sealing stress of rubber gasket due to compression and the operating pressure of plate exchanger. If the sealing stress is greater than the operating pressure, the sealing can be maintained; otherwise, leakage will occur. Therefore, the most important thing for plate exchange seal is to make the seal stress as high as possible and keep it for as long as possible.


Rubber is a viscoelastic material, different from metal springs in elasticity. This means that the rubber deformation under the long-term situation will occur stress relaxation, that is, under the constant tension or pressure, the seal stress will decay with the extension of time. There are two kinds of stress relaxation, one of which is physical relaxation, which is caused by the rearrangement between polymer molecules and filler particles. Such rearrangement gradually approaches equilibrium with the deformation of rubber, and the sealing stress has a linear relationship with the logarithm of time. The other is chemical relaxation, which is caused by the cracking of chemical bonds in rubber interconnections. Oxidation and temperature are important factors affecting such relaxation. Therefore, the rate of stress relaxation depends to a large extent on the temperature and the operating temperature range applicable to each rubber sheet. As a result, the stress relaxation deteriorates rapidly as the temperature rises, while that of fluoroelastomers suitable for the high temperature range is the opposite.


Through the above data we introduce two kinds of stress relaxation of rubber gasket of plate heat exchanger. Rubber gasket is a part that can not be ignored in plate changer, so its production and selection are equally crucial. I hope you can pay more attention in the process of using plate changer later.

Previous: The difference between single flow and double flow of plate heat exchanger

Next: The best flow rate of plate heat exchanger