Disk valves: device, principle of operation, types

What are gate valves? This is a stop valve that is installed in the pipeline. The main purpose of this device is to open or close the channel. The valve is equipped with a locking element, which is always installed perpendicular to the flow, which moves through the pipes.

Disk devices

As for the disk valve, this is a fairly simple shut-off valve, which differs only in that its locking element is made in the form of a disk. It is worth noting that they are often called gateways. Such valves are used in those pipelines along which either liquid or gaseous substance moves.

As for the diameter of the pipe, it should be in the range of 5 to 200 centimeters, and the maximum pressure inside should not exceed 20 MPa, the minimum figure is 0.4 MPa. There are restrictions on temperature - not higher than 450 degrees Celsius. Most often, butterfly valves are used if the diameter is in the range from 30 to 40 centimeters. Only in this case they will win in terms of the basic parameters of elements such as valves or cranes.

Device and principle of operation

As for the device of disk valves, among the main elements stand out: a shutter, a housing, a cover and several nozzles with which the structure is connected. Inside the case, of course, there is an opening through which the transported substance will pass. Inside the housing there is also a valve in the form of a disk, which is capable of moving up and down. You can control the device both manually and using an automatic system.

If manual control is applied, the process is as follows. When the flywheel begins to turn, the moving spindle of the structure will transmit this force to the valve. The disk locking element will rise, thereby opening the way for the transported substance.

Variety of gate valves

To date, quite a few different types of this design are produced. They differ in the following main characteristics:

1. Design feature of the locking element. This part can be made in the form of a wedge, and can be a parallel locking element. The butterfly valve belongs to the second type of construction.
2. Another difference is the diameter of the valve bore. The element may be full bore when the pipe diameter and the valve diameter match. They can be incomplete, in which case the passage of the structure is smaller than the total diameter of the pipe.
3. They also differ in the type of control. They can be either with a manual drive, or with electric, pneumatic, hydraulic.
4. The butterfly valve (ZD) may also differ in the way it is connected to the pipe. The design can be mounted either by welding, or by flange or coupling method.
5. The housing may also vary. It can be welded or cast.

Advantages and disadvantages of gate valves

This stop valve has a number of advantages.

1. The design is much simpler than other types of fittings.
2. The rotary butterfly valve has a sufficiently short length, making it more convenient to mount.
3. Valve operation is possible under a wide variety of environmental conditions.
4. In fully open mode, nothing prevents the movement of the transported substance.
5. When changing the direction of movement of the substance, the valve does not affect the operation of the valve.

However, the design has a number of disadvantages:

1. It is not recommended to use this type of shut-off valves if a substance that can be crystallized is transported through the pipeline.
2. The fittings are quite susceptible to pressure. According to this parameter, the gates, for example, win quite a lot against disk devices.
3. The response speed is quite low, due to which in an emergency it will not work to quickly shut off the flow of liquid or gas.
4. At the end of the course, there is a chance of getting a water hammer.

Butterfly valve

These stop valves are often referred to as HLS. They are made on the basis of conventional valves ZD. Technical characteristics are also almost the same.

The main purpose of these devices is to regulate the step level. The transported substance may be a gaseous or liquid substance. It can be water for technical use, oil, if its temperature does not exceed 120 degrees Celsius. Such equipment can be installed on pipelines that are characterized by high pressure, as well as on wellhead fittings instead of choke type chambers. The peculiarity of these structures is that they are usually made of a material that perfectly resists corrosion. The main material for production is 40X13 steel, produced in accordance with GOST 4543.