Needle valve- the principle of operation, design, advantages
Needle valve - is a structure of fittings, a shutter moving along the sealing surfaces of the seat. It is made in the form of a narrow conical cylinder.
The shape in which the shutter is made ensures a high level of tightness of the device and a smoother change in the cross-section of the passage. It is done with an increase and decrease in the volume of the working medium supply. The high degree of tightness of the valves allows them to be used for media in various states of aggregation - liquid and gaseous. Needle valves have no analogues and are produced by Needle Valve manufacturer in India only as single-seated ones.
They are widely used in industry to completely shut off the flow of working material, as well as to regulate its pressure and flow.
Device principle of operation
The needle valve device includes a body, a cover, a plug, a stem (spindle). The valve is operated manually or using a drive. It does this by transferring the torque from the handle or actuator to the stem, which in turn drives the valve. There is a stationary structural element inside the body - a saddle through the opening of which the working medium passes. The valve must be tight so that the plug and seat are carefully sealed to eliminate gaps.
DESIGN
According to Nrv Valve manufacturer in India, the typical design of this device is pneumatic control.
Depending on the location of the connecting nozzles, needle valves are angular. In these, the nozzles are located at an angle to each other, or through, the device.
Depending on the holes through which the device is connected to the system, the valves are divided into two-way and three-way.
Two-way - which have one medium inlet and one outlet, and three-way, which have one medium inlet and two outlets?
With three-way valves, it is possible to redirect the flow of the medium from one branch of the pipeline to another.
Pros of the needle valve
Before choosing and purchasing a valve, it is necessary to consider in more detail the technical features of the product. Particular attention should be paid to the main advantages and disadvantages. The key benefits of a needle valve are as follows:
- The simplicity of the device
- Ease of installation
- Long service life
- Complete control of water and gas flow
- High resistance to corrosion
- Tightness
Types and designs of needle valves
A large assortment of models is presented in the modern market. The cost of products depends on the type, purpose, size and material of manufacture. Based on their principle of operation, there are such device models:
Locking- Shut off the flow of the working medium.
Regulatory- Allow the most accurate regulation of the Hastelloy C276 Tube flow.
Balancing- Used to redirect flow between branches and change pressure.
Devices can also be classified according to the type of sealing:
Stuffing boxes- A special seal ensures a high level of tightness.
Bellows- The vacuum created acts as a sealant.
Before purchasing a needle valve, you need to take a responsible approach to the choice and choose the right product. Consideration should be given to the purpose and scope, technical parameters of the device.