There are some types of valves that are used specifically as on or off valves, with a ball valve or a check valve being a good example of these types of system-specific operations. There are other valves that can be used to stop, start and to control or regulated the flow of a liquid or a gas through a system, and a needle flow control valve is a great example of this type of versatility.
The Design Basics
The needle flow control valve is a plunger type of valve that is looks, at least from the outside, like any type of standard shutoff valve. There is usually a handwheel type of handle that is turned down to shut off or slow down the flow and turnout up to increase the flow or turn on the flow.
However, unlike a standard shutoff valve, the plunger inside is long and comes to sharp taper at the bottom. This unique design is where the needle control valve gets its name.
The pointed plunger fits down into a seat that is precisely crafted to hold the needle. By very small movements of the handle in the clockwise or counterclockwise area, a very precise flow can be maintained through the valve.
Depending on the system, a needle flow control valve can be manually operated, or it can be controlled to automated systems. The automated system can provide the most precision control over the flow rate through the valve, and this is typically used in production and processing systems.
These types of valves can be found in all types of industries and applications. They can be found in chemical processing plants, oil and gas refineries, when low-pressure hydraulics are used, or in any type of system with very low viscosity liquids or with many types of applications using gasses.