Sealing gaskets are frequently used sealing spare parts for machinery and equipment, which are materials that play a sealing role. From this definition, it is not difficult for us to know how important a gasket is. Therefore, how to install a gasket is worthy of our attention. The correct installation can ensure the sealing performance and make the equipment run smoothly. Otherwise, it will damage the sealing gasket. Let's take a look at what should be paid attention to.
The correct installation of gaskets requires that the flange connection, threaded connection, static sealing surface and gasket are well inspected and the other valve parts are intact. We should pay attention to the following aspects:
1. Before installing the gasket, apply a layer of graphite powder or graphite powder blended with oil or water on the rotating parts of the sealing surface, gasket, thread, bolt and nut. The gasket and graphite should be kept clean.
2. The gasket should be installed on the sealing surface with a correct position, and there should not be an incline; it should not extend to the valve cavity or platform shoulder.
3. Only one gasket is allowed to install, and two or more gaskets are not allowed to be installed between the sealing surfaces to eliminate the insufficient gap between the two sealing surfaces.
4. The oval gasket should be sealed so that the inner and outer rings of the gasket can be in contact, and the two ends of the gasket should not be in contact with the bottom of the groove.
5. For the installation of O-rings, in addition to the ring and groove that should meet the design requirements, the compression amount should be appropriate. Under the premise of ensuring sealing, the smaller the compression deformation rate is, the better it is, which can extend the service life of the O-ring.
6. The valve should be in the open position before the gasket is covered so as not to affect the installation and damage the valve. When closing the cover, align the position, and do not push or pull to contact the gasket so as to avoid displacement and scratches of the gasket.
7. For the installation of bolted or threaded gaskets, the gasket should be in a horizontal position. Grip wrenches are not allowed to be used for the gasket cover with threaded connections and positions with wrenches.
8. Before the gasket is pressed, the pressure, temperature, properties of media, and material characteristics of gaskets should be learned well, and the pre-tightening force should be determined. The pre-tightening force should be as small as possible under the condition that no leakage occurs for the pressure test.
9. After the gasket is tightened, make ensure that there is a pre-tightening gap for the connecting parts to prepare for pre-tightening when the gasket leaks.
10. High-temperature creep, stress relaxation, and increased deformation will occur for bolts at high temperatures, leading to leakages at the gasket, which requires thermal tightening. On the contrary, under low-temperature conditions, bolts will shrink and require cold loosening.
11. When a liquid gasket is used for the sealing surface, the sealing surface should be cleaned or treated. The flat sealing surface should be consistent after grinding, and the adhesive should be evenly coated; the air should be removed as much as possible. The adhesive layer is generally from 0.1 to 0.2 mm.
12. When the PTFE film raw tape is used for thread sealing, the starting point of the film should be stretched and glued to the thread surface, and then the excess tape at the starting point should be removed to make the film sticking to the thread a shape of a wedge.
Through the above introduction, you know how the gasket is installed. The installation is not complicated, but many details need to be paid attention to. After the details are handled, the installation can be smooth. The correct installation is related to the sealing and operation of the equipment, so the installation operator should keep the above items in mind and check them carefully during installation.
