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Valve Seal Installation
- Jun 02, 2018 -

Sealing gaskets are commonly used sealing spares for machinery and equipment and are used as sealing materials. From this definition, it is not difficult to know how important the sealing gasket is, so how to install the sealing gasket is worth our attention. The correct installation can guarantee the sealing performance and make the equipment run smoothly. Otherwise, it will damage the sealing gasket. Next, we look specifically at what we should do next.

    The correct installation of the gasket shall be performed in the flange connection structure or the threaded connection structure, the static sealing surface and the gasket are checked, and the other valve parts are intact.

    1. Before installing the gasket, apply a layer of graphite powder or graphite powder with engine oil (or water) to the rotating surface of the sealing surface, gaskets, threads, and bolts and nuts. The gasket and graphite should be kept clean.

    2, the gasket installed on the sealing surface must be in the correct, can not be skewed, can not reach into the valve chamber or shelving shoulder.

    3, the installation of the gasket is only allowed to install one, do not allow two or more pieces in the sealing surface to eliminate the gap between the two sealing surfaces.

    4. The elliptical gasket shall be sealed so that the inner and outer rings of the gasket are in contact with each other, and both end surfaces of the gasket may not be in contact with the bottom of the groove.

    5, O-ring installation, in addition to the ring and groove should meet the design requirements, the amount of compression should be appropriate, under the premise of ensuring the seal, the smaller the compression deformation rate the better, can extend the life of the O-ring.

    6. Before the gasket is in the upper cover, the valve should be in the open position to avoid affecting the installation and damage to the valve. When aligning the cover, do not use a push-pull method to make contact with the gasket so that the gasket will not be displaced or scratched.

    7. The installation of bolted or threaded gaskets shall be such that the gasket is in a horizontal position (the gasket cover is screwed on, and the wrench position must not be used with a pipe wrench).

    8. Before the gasket is pressed tightly, the pressure, temperature, properties of the medium, characteristics of the gasket material should be clearly understood, and the preload must be determined. The pre-tightening force should be kept as low as possible in the absence of pressure drop.

    9. After the gasket is tightened, it is necessary to ensure that there is a pre-tightened gap in the connecting part to prepare for room for pre-tightening when the gasket leaks.

    10. When working at high temperature, the bolt will produce high temperature creep, resulting in stress relaxation, increased deformation, resulting in leakage at the gasket, requiring heat tight; conversely, under low temperature conditions, the bolt will shrink and need to be cold.

    11. When the sealing surface uses a liquid gasket, its sealing surface should be cleaned or surface treated. The plane sealing surface should be matched after grinding, and the coating adhesive should be uniform. Air should be excluded as much as possible. The adhesive layer is generally 0.1-0.2mm.

    12. When using Teflon-coated raw tape for thread sealing, the starting point of the film should be thinned, stuck on the thread surface, and then the excess point tape at the starting point should be removed to make the film stuck on the thread be wedge-shaped.

    Through the above introduction, we all know how the gasket is installed. Installation is not complicated, but there are many details that need attention, details are handled well, and the installation will be smooth. The correct installation or not relates to the sealing and operation of the equipment. Therefore, the installation and operation personnel should keep the above items in mind and carefully check the installation work.