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2021

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How to install valve seal?

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Sealing 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 sealing gasket is, so how to install the sealing gasket is worthy of our attention. Correct installation can ensure sealing performance and ensure smooth operation of the equipment. Otherwise, it will damage the sealing gasket.

Sealing 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 sealing gasket is, so how to install the sealing gasket is worthy of our attention. Correct installation can ensure sealing performance and ensure smooth operation of the equipment. Otherwise, it will damage the sealing gasket. Next, let’s take a closer look at what to do.   The correct installation of the gasket should be carried out after the flange connection structure or threaded connection structure, static sealing surface and gasket have been checked and the other valve parts are intact. 1. Before installing the gasket, apply a layer of graphite powder or lubricant mixed with graphite powder and engine oil (or water) on the sealing surface, gasket, threads and rotating parts of bolts and nuts. The gasket and graphite should be kept clean.
  
    


    2. The gasket must be installed on the sealing surface in a centered and correct manner, and must not be deflected, extend into the valve cavity or rest on the shoulder. 

 

    3. Only one gasket is allowed to be installed. It is not allowed to install two or more gaskets 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 are in contact, and the two end surfaces of the gasket must not be in contact with the bottom of the groove.


    5. When installing the O-ring, in addition to the ring and groove should meet the design requirements, the amount of compression must be appropriate. On the premise of ensuring sealing, the smaller the compression deformation rate, the better, which can extend the life of the O-ring.


    6. Before the gasket is placed on the upper cover, the valve should be in the open position to avoid affecting the installation and damaging the valve parts. The position must be aligned when covering, and no push-pull method should be used to contact the gasket to avoid displacement and scratches on the gasket.


    7. When installing bolted or threaded gaskets, the gaskets should be in a horizontal position (threaded gasket covers and pipe wrenches should not be used if there is a wrench position).


    8. Before compressing the gasket, the pressure, temperature, nature of the medium, and gasket material characteristics should be clearly understood to determine the pretightening force. The pre-tightening force should be minimized to ensure that there is no leakage during the pressure test.


    9. After tightening the gasket, ensure that there is a pre-tightening gap in the connecting parts to allow for pre-tightening in case of gasket leakage.


    10. When working at high temperatures, the bolts will produce high-temperature creep, resulting in stress relaxation and increased deformation, resulting in leakage at the gasket, which requires heat tightening; conversely, under low temperature conditions, the bolts will shrink and require cold loosening.


    11. When the sealing surface uses a liquid sealing gasket, the sealing surface should be cleaned or surface treated. The flat sealing surfaces should be ground and matched, the adhesive should be applied evenly, and air should be eliminated 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 stretched thin and adhered to the thread surface, and then the excess tape at the starting point should be removed to make the film adhered to the thread into a wedge shape .

 

    Through the above introduction, everyone knows how to install the sealing gasket. The installation is not complicated, but there are many details that need to be paid attention to. If the details are taken care of, the installation will go smoothly. Correct installation is related to the sealing and operation of the equipment, so installation operators should keep the above matters in mind and check carefully when performing installation work.