The shut-off valve is a fitting, the purpose of which is to quickly turn off the pipeline as a whole or part of it according to technological requirements or in the event of an emergency. Its main advantage is speed, since when the device is closed, the spring works instantly. Spring charging is carried out by means of an electric or pneumatic actuator.
Shutoff valve: varieties
This type of valve can have a piston or diaphragm pneumatic actuator. In addition, the shut-off valve can belong to one of the types: straight, angle, one- or two-seated. According to the method of closing, this type of valve can be: spring, pneumatic, electromagnetic or closing weight.
Scope of application
The straight-through body shut-off valve is used for transporting slurry abrasive orcontaminated environments. There are no dead zones in such a device. Steel angle shut-off valve with double-acting hydraulic piston actuator, used in high pressure environments.
At the moment, this type of fittings has such design features that steam is most actively used as a control medium in it. Such a valve works in 1.5-10 seconds. Its cylinder and body are sealed with helically wound gaskets made of corrosion-resistant steel with an asbestos layer. If compared with the external environment, then the tightness of this type of valves is quite high, which is facilitated by the absence of glands in them. All this allows to significantly increase their reliability during operation and improve performance.
The shut-off valve for water: the difference between the new modification and the old one
The design of this type of reinforcement has been significantly changed, so several significant differences can be traced. The most important features in the new modification are:
- increased resistance to polluted media;
- increased level of tightness;
- reliability increased to the maximum;
- acting speed surpasses old modifications;
- pipeline can overlap in two directions: forward and reverse.
This type of valve is most often used in the energy, pulp and paper and food industries, as well as in water treatment and treatment.
Requirements for shut-off valves
Basicthe requirement in this case is the response speed. Compliance with this is ensured by equipping the valve with a spring or more. Typically, these designs use Belleville or helical springs. When using an electric actuator, the design of the valve assumes the presence of latches that hold the spring in the cocked state, and they are controlled by electromagnets. The automatic shut-off valve works instantly and, if necessary, just as quickly goes into standby mode.
All varieties of this type of valve can be made from different materials: steel, plastic, cast iron or stainless steel.
