- Seen : 515 View
Valves are a tool to control the flow and pressure of fluids that are widely used in various fields, such as in industrial works such as power plants, refineries, petrochemical industries, pharmaceutical and food industries, etc.
Valves are produced in different materials such as cast iron, steel, brass, and bronze according to their use. For example, brass valves are used to transfer water flow due to the less corrosiveness of water due to the neutrality of the water (not acidic or alkaline), and tin bronze valves are used in petrochemical industries where fluids They have acidic or basic properties, it is widely used.
One of the types of valves is needle valves
The needle valve is one of the most important and widely used valves, which is usually used to adjust the fluid flow rate. The needle valve has a long needle-shaped cone at the end of its stem, which plays the role of a disk in this valve. These valves are very similar to globe valves in terms of structure and function; With the difference that the disk of needle valves is very narrow in the shape of a cone and it is spherical in ball valves.
In a needle valve, a long needle cone passes through a valve located on the seat of the valve, which has a larger diameter than the needle, and its end is placed on the opening of the valve. When opening the valve by turning the stem, the needle is raised with a twisting motion and the flow is gradually established. Therefore, this type of design provides the possibility of gradually increasing or decreasing the fluid flow in the flow path. A 90˚ turn in the lever of these valves can change the valve from fully closed to fully open.
Needle Valve Applications
Needle valves are often used as an accessory member in more complex valves. For example, these valves are used in some types of pressure relief valves.
Most of the constant pressure governor pumps use needle valves in order to reduce the pressure fluctuations during pump discharge. These valves are also used in automatic ignition control systems in order to accurately adjust the amount of fuel entering the combustion chamber. Needle valves are also used in laboratory applications where the accuracy of the flow rate is very important for conducting experiments.
Needle valves are not suitable for the passage of viscous fluids and fluids containing solid particles and are mostly used for vapors and non-viscous fluids. One of the common fluids used in needle valves is propane gas, which is called a propane valve.
Saler Company Information
