Gaskets are frequently used sealing spare parts for machinery, equipment, etc., and are materials that play a sealing role. From this definition, it is not difficult for us to know how important the gasket is, so how to install the gasket is worthy of our attention. Correct installation can ensure the sealing performance and make the equipment run smoothly, otherwise it will damage the sealing gasket. Next, let's look at how to do it.
The correct installation of the gasket should be carried out under the condition that the flange connection structure or thread connection structure, static sealing surface and gasket have been checked, and other valve parts are intact.
1. Before installing the gasket, apply a layer of graphite powder or a weeping agent mixed with engine oil (or water) on the sealing surface, gasket, thread and the rotating parts of the bolt and nut. The gasket and graphite should be kept clean.
2. The gasket should be installed on the sealing surface to be centered and correct, not deflected, not protruding into the valve cavity or resting on the shoulder.
3. Only one piece of mounting gasket is allowed, and two or more pieces are not allowed to be installed between the sealing surfaces to eliminate the gap between the two sealing surfaces.
4. The airtightness of the elliptical gasket should make the inner and outer rings of the gasket contact each other, and the two ends of the gasket should not be in contact with the bottom of the groove.
5. For the installation of the O-ring, except that the ring and groove should meet the design requirements, the amount of compression should be appropriate. Under the premise of ensuring sealing, the smaller the compression deformation rate, the better, which can prolong the life of the O-ring.
6. Before the gasket is on the cover, the valve should be in the open position, so as not to affect the installation and damage the valve parts. When covering, the position must be aligned, and the push-pull method must not be used to contact the gasket, so as to avoid displacement and abrasion of the gasket.
7. When installing bolted or threaded gaskets, the gaskets should be in a horizontal position (the threaded gasket cover, if there is a wrench position, do not use pipe wrench).
8. Before the gasket is tightened, the pressure, temperature, properties of the medium, and the characteristics of the gasket material should be clearly understood, and the pre-tightening force should be determined. The pre-tightening force should be minimized as far as possible without leaking in the pressure test.
9. After the gasket is tightened, there should be a pre-tightening gap between the connecting parts, so that there is room for pre-tightening when the gasket leaks.
10. When working at high temperature, the bolts will produce high-temperature creep, stress relaxation, and increased deformation, resulting in leakage at the gasket, which needs to be heat-tightened; on the contrary, under low-temperature conditions, the bolts will shrink and need to be cold-loosen.
11. When the sealing surface adopts liquid sealing gasket, the sealing surface should be cleaned or surface treated. The flat sealing surface should match after grinding, the adhesive should be applied evenly, and the air should be removed as much as possible. The adhesive layer is generally 0.1-0.2mm.
12. When using polytetrafluoroethylene film raw tape for thread sealing, the starting point of the film should be thinned first, and stick to the thread surface, and then the excess tape at the starting point should be removed to make the film sticking to the thread into a wedge shape.
Through the above introduction, everyone knows how to install the gasket. The installation is not complicated, but there are many details that need to be paid attention to. If the details are handled well, the installation will be smooth. Whether the installation is correct or not is related to the sealing and operation of the equipment, so the installation and operation personnel should keep the above items in mind and check carefully when performing the installation work.