The stop valve is a piece of pipe fittings used in various situations. In such a device, the movement of the locking element is parallel to the axis of the main fluid flow inside.
Shut-off and control valves with an electric actuator are focused on changing the flow rate of the working medium that moves through the pipeline. The shut-off valve can be made of bronze, steel and cast iron, it is used to regulate the liquid or gas flow through the pipeline, as well as an element that blocks this flow. If we take the design features of the device as the basis for classification, as well as its purpose, then there is also a solenoid shut-off valve, which allows you to control the environment in the system at a distance, as well as flange and coupling types of valves.
There are many varieties of this type of reinforcement. The choice of a particular one depends on the characteristics of the technological process, as well as on the tasks assigned to the safety shut-off valve. An important factor is the types of systems where it is used.
Valves are quite widespread, performing the functions of shut-off valves, which allows for high-quality sealing in the shut-off body, while the design of the device is quite simple. Valves are used for gaseous and liquid media with a wide range of operating properties: pressure and temperature. They are usually used on pipelines that have a small diameter, since with large sizes one has to face a situation where the force required to operate the valve increases significantly, and the design becomes more complicated to ensure the correct fit of the valve placed on the body seat.
The check valve has a number of advantages:
- the ability to use in conditions of high pressure and temperature, vacuum, aggressive and corrosive environments;
- ease of repair and maintenance directly in operation.
By design features, valves are in many ways similar to gate valves, however, the fundamental difference is the way the valve is moved, which gives the valves additional advantages:
- full opening requires a small shutter stroke, so the weight and height of the device is also quite small;
- the tightness of the shutter in the valves is much easier to ensure than invalves;
- when opening and closing the valve, friction of the seal is almost eliminated, which significantly reduces the degree of wear;
- bellows can be used as reinforcement seal.
The safety shut-off valve also has certain disadvantages:
- high hydraulic resistance, which, with a significant diameter of the passage and high speed of the medium, creates significant energy losses, which causes the need to increase the initial pressure in the system;
- diameter limits valve application limits;
- in most designs there are stagnant zones where mechanical impurities accumulate from the working medium, and this significantly increases corrosion in the valve body.
In any case, this type of reinforcement is widely used.
