self pressureadjustvalveBecause it does not need other external energy sources such as power supply and air source, it is only driven by the energy of the medium itself, which is energy-saving and environmentally friendly, and is easy to use. After installation, the pressure value can be set and then put into automatic operation. Therefore, the control accuracy is not required. It has been used more and more widely in occasions where the power source and air source are lacking.
However, thisvalveDoorIt also needs to be correctly selected, installed and used correctly to ensure that there will be no problems after being put into operation. Needless to say about type selection, for example, whether the regulating valve is used to control the pressure before the valve or the pressure after the valve, whether the medium is at room temperature or high temperature, whether it is corrosive, high working pressure, etc., must be clear in advance, we mainly Talk about installation and use. Because I recently encountered a case of problems in the use of self-operated pressure regulating valves, which is very representative.
The valves are used in steam pipelines, and after only one or two months of being put into use, users report for repairs. When I went to the scene, a large amount of steam was discharged from the vent hole of the regulating valve membrane head, and the noise was extremely loud and the momentum was astonishing. The cause of the accident is obviously that the steam directly enters the membrane head without condensation and burns out the membrane.
For self-operated pressure regulating valves used in steam pipelines, a condensing tank must be added between the actuator and the pipeline during installation to prevent steam from entering the actuator membrane head. Moreover, the regulating valve must be installed head-down, and the condensing tank should be higher than the For the first use of the membrane head, be sure to fill the condensation tank and the membrane head with water. Look at the installation method on site and ask the on-site instrumentation personnel, there is no problem with these, so what caused it? It’s puzzling. Later, I inquired carefully about an operator, and accidentally learned that after the valve was installed and put into use, the copper pipe joint between the condensation tank and the membrane head has been leaking intermittently. It turned out to be like this. The water leakage caused the water in the condensation tank to leak slowly, and the steam entered the membrane head, which burned the membrane.
It can be seen that when the self-operated pressure regulating valve is used on the steam pipeline, more attention must be paid to the installation and maintenance. In order to ensure the normal operation of the regulating valve, the joint must not leak water, and the condensing tank must not be short of water. Periodic inspection is required. Add water as needed. In fact, not only self-operated pressure regulating valves, but other self-operated regulating valves also need to pay attention to maintenance and maintenance during use.
In addition, if the steam pressure is high, it is better to choose a piston actuator instead of a membrane actuator, because the pressure that the diaphragm can generally withstand does not exceed 0.4Mpa. Although it can be used, it will greatly reduce the service life.