Several key details to note during the installation of a self-operated steam pressure regulating valve

The self-operated pressure steam regulating valve is a type of self-operated regulating valve. Since it does not require external energy sources such as electrical power or gas supply, and is solely driven by the energy of the medium itself, it is both energy-saving and environmentally friendly, as well as convenient to use. After installation, the pressure value can be set, and the valve can be put into automatic operation. Therefore, it has found increasingly widespread use in scenarios where control precision requirements are not high and there is a lack of electrical power or gas supply.

However, to ensure trouble-free operation after commissioning, self-operated steam pressure regulating valves also require proper selection, installation, and usage. Regarding valve selection, such as whether the regulating valve is used to control the upstream or downstream pressure, whether the medium is at normal temperature or high temperature, whether it is corrosive, and the working pressure, among other factors, will not be elaborated on here. It is crucial to ascertain these details beforehand. This passage primarily focuses on issues related to installation and usage, as a recent incident involving a self-operated steam pressure regulating valve was highly representative.

The self-operated steam pressure regulating valve is installed on a steam pipeline. Within just one or two months of being put into service, the user reported a malfunction. Upon arriving at the site, it was observed that a significant amount of steam was escaping from the exhaust vent on the diaphragm head of the self-operated steam pressure regulating valve, accompanied by extremely loud noise. The cause of the accident was clearly that steam had been directly installed into the diaphragm head without passing through a condenser, thereby burning out the diaphragm.

For self-operated steam pressure regulating valves used on steam pipelines, a condenser must be installed between the actuator and the pipeline to prevent steam from entering the actuator diaphragm head. Additionally, the self-operated steam pressure regulating valve must be installed with its head facing downward, and the condenser must be positioned higher than the diaphragm head. During initial use, both the condenser and the diaphragm head must be filled with water. Upon examining the installation method on-site and questioning the on-site instrumentation personnel, it was confirmed that these requirements had been met. So, what caused the issue? This remained a perplexing question. Later, after carefully questioning an operator, it was inadvertently discovered that the joint between the condenser and the diaphragm head had been intermittently leaking water since the valve's installation and commissioning. It turned out that the leakage had caused the water in the condenser to gradually drain away, allowing steam to enter the diaphragm head and burn out the diaphragm