Industry news

The safety valve often has the problem of internal leakage during take-off, how to solve it?

The safety valve is a kind of overpressure protection device. When the pressure in the equipment, container or pipeline exceeds the allowable value, the valve will automatically open and then discharge all to prevent the pressure in the equipment, container or pipeline from continuing to rise; when the pressure drops to the specified value When the value is reached, the valve will automatically close in time to protect the safe operation of equipment, containers or pipelines.

At present, safety valves are mainly used in boilers, pressure vessels and pipelines, which play an important role in protecting personal safety and equipment operation, and are widely used in pharmaceutical and other industries. It is understood that since 2013, my country’s safety valve industry market has gradually expanded, and the number of companies with qualifications to produce safety valves has also begun to increase, and the share of imported valves in the domestic market has gradually declined, and domestic valves have gradually risen. Looking at the future development space of domestic safety valves is very broad.

For users, choosing a safety valve produced by a regular manufacturer, correct installation, and reasonable operation are the prerequisites for ensuring its stable operation. However, during the use of safety valves, the problem of internal leakage often occurs, so how to find out the reason And solve it? Three directions are given in the industry for the industry's reference.

First, there is a leak in the safety valve. According to the industry, when a small leak occurs in a safety valve, it is generally not easy to find, but even a small leak point will expand and corrode. In the face of the situation, users need to check the safety valve.

The test method is to cover the sealing surface with water during the pressure test, and to observe whether there is foam after the pressure. The industry pointed out that “the safety valve program stipulates that the soft seal must be bubble-free, and the hard seal may be available, but the bubble generation speed must be within a certain range. This should be done after the calibration is completed, because the safety valve may be It will destroy the sealing surface."

Second, the spring produces fatigue. It is understood that the spring is greatly affected by temperature and environment (if the safety valve is closed, the influence of the medium should also be considered). If this is the reason, it is necessary to consider the selection or quality of the safety valve. This also requires users to consider whether the selection of the safety valve is reasonable and whether the quality is satisfactory when selecting a safety valve.

Third, the pipeline factor. For example, vibration and shock may cause excessive pressure on the safety valve, and the valve core will detach from the sealing surface of the valve seat, causing damage and slag inclusion.

According to the industry, in fact, the manufacturing requirements of safety valves are quite high. Since the sealing force of safety valves is equal to spring force-medium pressure, it is close to general places such as power plant main steam, water supply pressure and working pressure safety valves, so the actual sealing is The sealing force on the surface is not too large, and a good sealing is desired under low action. The sealing surface must be processed with high precision and the material has high requirements.

Fourth, the performance of the spring is unstable. The industry believes that the spring performance of the safety valve must be very stable, because the high temperature of the medium will cause the output of the spring to drop, which will lead to a tight seal. In particular, the steam safety valve has a recoil plate, and general leakage may cause the safety valve to jump, thereby affecting the power supply.

In addition, the industry recommends not to carry out self-maintenance. Safety valves are an important part to ensure the safe operation of equipment. Only qualified inspection units can inspect and maintain safety valves. It is recommended to disassemble and assemble once a year and submit for inspection.

PREVIOUS:Safety valve and its safety technical requirements

NEXT:VITAL Plug Valve are Ready

Leave a Reply





Leave a message