Like other Valves, A needle valve is used to control flow which is required for regulation. In Simple words, the needle valve is used to control flow rates of gasses, liquids or fluids. Needle Valve is similar to a globe valve with respect to design with, the difference is the sharp needle-like a disk, however, it is used for low flow rates and have a large pressure drop from the inlet to the outlet. The Port size of a needle Valves ranges from 1/8” up to 2”. The needle valve has the ability to shut off the flow entirely.
These valves are used to control and check the flow of liquid and gas, but during the time of high pressure, this valve is subjected to suffer damage. These valves can easily be used for both on and off valves, along with a system for throttling service.
Needle valves are made from durable materials such as copper, plastic, brass, steel or aluminum. This valve is used in many different systems and applications; however, plastic valves or brass valves are used sometimes depending on the requirements. As the valve is installed inside the piping system, and also there are additional devices installed it is impossible to gauge this from sight. Needle Valves by their design allow pressure to be added in small increments.
Features of Needle Valves
· Needle Valves are offered in a variety of materials, size and end connections.
· Provide reliable and consistent flow control
· Can be operated both manually and automatically.
· Can Withstand corrosive and also at extreme conditions.
Needle Valve Operation
Needle valves operate both manually and automatically. When operated by both it provides precise control of the flow rate. Needle Valves has a handwheel or a small handle located on the plunger that controls the position of the plunger. The valve’s Needle-like plunger fits into the seat. Because of this unique design, Needle Valves can precisely and accurately control the flow of fluid that passes through the valve. The handle of the valve is connected to the plunger, which is also called a stem. When the handle is turned on, the plunger moves up or down based on the threads. The locking nut prevents it from fully unscrewing. As the plunger moves down, the tapered pointed end comes into contact with the valve seat to fully seal the orifice. Often, the valve seat is also tapered. There are various options and sizes available to connect it to a pipe or hose through the port connection on the input and output. The bonnet is connected to the valve housing, which can be made out of different materials like brass or stainless steel.
Needle Valve Uses
Needle valves are commonly used to control flow and protect gauges from damage caused by sudden pressure coming through fluids, liquids or gas. Needle valves are usually used in low-pressure hydraulic systems, chemical processing, and other gas and liquid services.
These valves can also be applied to high-temperature and oxygen service based on their materials. It’s important to choose a needle valve made with the material that’s best suited for the service you need. This will help to preserve that valve’s service life and keep your systems running smoothly and safely.
More Resources:
· Different Types of Valves and their Uses
KHD Valves Automation 