If the leakage of the valve beyond the rated range occurs in the sealing valve and valve seat part of the safety valve, the loss of the medium will occur and the sealing material will be destroyed. Under normal circumstances, the sealing surface of the safety valve is mainly composed of metal materials, and it is costly and smooth to complete, but in the case of secondary pressurization of the medium with pressure, it is unlikely to be completely sealed without leakage. of. Therefore, in the rated pressure environment, the safety valve using steam as a medium can be detected by naked eye observation and ear hearing. The main reasons for valve leakage are the following two points:
(1) Dirty dirt, debris, etc., are formed on the sealing surface, and the originally sealed surface is blocked and blocked, resulting in a gap between the valve plug and the valve seat, resulting in leakage of the valve. To solve this type of problem, it is usually a matter of dirt on the sealing surface. When the boiler is temporarily decommissioned for maintenance, it is necessary to conduct a running test on the safety door first, and if there is a leakage phenomenon, it must be overhauled. The interval between runs is 20 minutes after cooling completely.
(2) Damage to the sealing surface. There are many reasons, such as: First, the material used for sealing is not qualified. After a safety valve is used for many years, the strength of the sealing surface is easily weakened due to continuous switching and overhauling, and the sealing ability is weakened. The recommended measure to solve this problem is to flatten the original sealing surface and perform secondary processing welding according to the original drawings to enhance the hardness and strength of the surface. Also pay attention to the damage on the surface, must not be sloppy.
The second is maintenance quality. Due to the poor level of maintenance, the valve plug and the valve seat cannot reach a certain level in the grinding process. The solution is to use grinding or even turning, depending on the severity of the damage, to repair the sealing surface as much as possible.
Third, improper assembly or incorrect part size. In the entire assembly work, the valve plug and the valve seat are not completely aligned, or there is a serious light transmission problem on the bonding surface. It is also possible that the sealing of the valve plug and the valve seat is too loose to be truly sealed. The solution is to strictly inspect the site of the ninth person, the site of the occupant, the identity of the culprit, and the culprit (3) B.å ‡ å ‡ å ‡ å ‡ 跫趺芊饷娴 跫趺芊饷娴 跫趺芊饷娴 / / / / / /span>
The plug valve is a closed or plunger-shaped rotary valve, which can be opened or closed by rotating 90 degrees to connect or separate the channel opening on the valve plug and the channel opening on the valve body.
Its valve plug can be cylindrical or conical in shape. In cylindrical plugs, the passages are generally rectangular; in conical plugs, the passages are trapezoidal. These shapes allow for a lightweight construction of the plug valve. Best suited for switching off and on media and for diverting applications, but may also be used for throttling depending on the nature of the application and the erosion resistance of the sealing surfaces
Plug Valve,Plug Gate Valve,Eccentric Plug Valve,Spherical Plug Valve
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