Needle valve, as a member of the big valve family, has been playing an important role at gradually and ultimately shutting off the flow. Various needle valves are used to regulate the amount of a substance released by flow, pressure and direction. Therefore, they are the indispensable parts of most industrial process. The specific part in the valve itself is the elaborately designed structure, including the design of the point.
In fact, the design of many components of the needle valve has done great favors. At this moment, take the parts called the valve stem and seal for example. No matter what, these fittings are making contributions to the performance of the entire equipment.
The valve stem is the necessary part of the valve itself. It is specially designed to ensure a precise flow control. Various valve stems are usually designed with the thin threads. Generally speaking, the most common types are the threads in fine, coarse, wetted and non-wetted style. These four types hold their own advantages. For example, fine threads are able to be spaced closely with the thin appearance, leading to the precise flow control in the minimal amounts. And coarse threads are the threads which are used to take out the maximum flow. Besides, the wetted stem threads and non-wetted stem threads vary on the point whether they are exposed to the fluid or not. The former one does and the latter does not. All in all, they are able to provide precise flow control.
And the seal is also the indispensable part of the needle valve. If the seal is not good enough, the entire equipment would result in poor performance, even in failure to work. In fact, there is also some available types of the seal. It generally has three types. They are the type in plastic to metal, metal to plastic and metal to metal. Each type has its outstanding features. For example, the plastic to metal seal is quite popular in gas molecules resulting from its appreciated scalability and reliable tightness.
In words, all components are responsible for the entire performance of the needle valve. As a result, they are able to be used to control the flow of liquid or gas and protect fragile gauges.