In all pipelines without exception, the product is transported under a certain pressure. In order to block its flows, shutoff valves are used, and an adjustable valve is one of its varieties. With its help, you can narrow to a minimum or expand to a maximum the cross-sectional area in the pipe. Accordingly, the product, whether it is water, alkali or oil, will flow in a small stream or be thrown out of the tap under pressure. It should be noted here that the adjustable valve does not serve to shut off the flow completely, and then open it. To do this, shut-off valves. It is necessary solely to control the pressure in the system.
Types of management
If the adjustable valve in the domestic pipeline is under manual control, then in the conditions of industrial operation various types of actuating mechanisms are used. Sensors are attached to the armature, taking indicators of the state of the transported product. The received information is transmitted to microcontrollers connected to the drive, which is started by their signal. It moves the adjustable valve to a new position. The types of control depend on the drive mechanism:
- Pneumatic drive.
- Electromagnetic drive.
- Electric.
- Drive with hydraulic mechanism.
Some enterprises still use manual control, but this is already becoming a rarity. But the electric control valve has the widest range of industrial applications.
From the drive, a force is applied to the shutter of the adjustable valve. It consists of two elements: a saddle and a plunger. The seat is stationary in the housing. But the plunger controls the flow. When it narrows the cross section, the velocity of the liquid or gas and the pressure in the pipeline change. If the plunger enters the seat, then the cross section becomes minimal. High throughput pipelines use valves with two-week valves to provide more efficient pressure control.
Economic forces
Economic efficiency from the use of certain valves depends on many factors, including the type of fastener. It can be welded, nipple, flanged, mounted on a coupling or a flange. Reliability of the connection makes it possible to operate the control valve for a long time. The installation price, the complexity of maintenance and care of the drive mechanisms ultimately determines the profitability of the pipeline. A welded joint is reliable and inexpensive in cost, but it can only be used for steel valves.
Design differences
Despite the apparent similarity with valves, adjustable valves have their own design features. First of all, you should choose an option with a given flow direction. Next, you should pay attention to what section of the pipeline fittings are needed. If it is designed for a flat, not changing the direction of the route, then the check valve is suitable. In systems having bends, angular structures are used. There are mixers with several nozzles. For example, a three-way valve has two inlets and one outlet.