How should the valve sealing gasket be installed?

Sealing gasket is a sealing part often used in machinery, equipment, etc., is a sealing material, but also an indispensable part of machinery and equipment, so it is very important to know how to install sealing gasket. The correct installation can ensure the sealing performance of the machinery and equipment and make it run smoothly, otherwise it will damage the sealing gasket and cause leakage.

Before installing the gasket, check the flange connection structure or thread connection structure, static sealing surface and gasket, etc., and install the gasket only when other valves are intact.

1. Before installing the gasket, the sealing surface, gasket, thread and the rotating parts of bolts and nuts are coated with a layer of graphite powder or lubricant blended with oil (or water) of graphite powder. The gasket and graphite should be kept clean.

2, the gasket should be installed on the sealing surface to meet and correctly, can not be tilted, can not extend into the valve cavity or the shoulder of the table.

3, the installation gasket is only allowed to install one piece, and it is not allowed to install two or more pieces between the sealing surface to eliminate the gap between the two sealing surfaces.

4, the sealing of the oval gasket should make the inner and outer rings of the gasket contact, and the two ends of the gasket shall not contact the bottom of the groove.

5, O-ring installation, in addition to the ring and groove should meet the design requirements, the compression amount should be appropriate, under the premise of ensuring sealing, the smaller the compression deformation rate, the better, can extend 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. The cover should be aligned to the position, and should not be in contact with the gasket by pushing and pulling, so as to avoid displacement and bruising of the gasket.

7, the installation of bolted or threaded gaskets should make the gasket in a horizontal position (threaded gasket cover, with a wrench position shall not use pipe clamp).

8, before the gasket compaction, the pressure, temperature, the nature of the medium, the characteristics of the gasket material should be understood clearly, and the pre-loading force should be determined. The preload should be minimized under the condition that the pressure test does not leak.

9. After the gasket is tightened, it should be ensured that the connecting parts have a pre-tightening gap to prepare for the space for pre-tightening when the gasket leaks.

10, when working at high temperature, the bolt will produce high temperature creep, resulting in stress relaxation, deformation increase, resulting in leakage at the gasket, the need for hot tightening; On the contrary, under low temperature conditions, the bolt will shrink and need to be loosened.

11, when the sealing surface uses a liquid sealing gasket, the sealing surface should be cleaned or treated. The surface sealing surface should be consistent after grinding, the coating adhesive should be uniform, and the air should be excluded as far as possible. The adhesive layer is generally 0.1-0.2mm.

12, When the thread seal is made of polytetrafluoroethylene film tape, the starting point of the film should be forcibly pulled thin, stuck on the thread surface, and then the excess tape at the starting point is removed, so that the film stuck on the thread is wedged.

The installation of gaskets is not complicated, but there are many details that need to be paid attention to, and the details can be successfully installed.

Whether the correct installation is related to the sealing and operation of the equipment, so the installation and operation personnel should keep the above matters in mind and carefully check the installation work.