Detail the working principle of screw valve

Screw valve, as an efficient and reliable fluid control equipment, its working principle is exquisite and practical. Here is a detailed explanation of how it works:

Structural composition
The core parts of the screw valve mainly include screw and nut. The screw is usually designed to be fixed, while the nut is tightly attached to the valve body and can move along the axis of the screw. This design makes the screw valve structurally compact and robust.

Motor mechanism
When the screw is driven by external power to rotate, this rotating movement is transformed into a straight line movement of the nut along the screw axis through the meshing action between the threads. The internal design of the nut has a through hole, and the opening or closing state of this through hole directly determines whether the fluid can pass through the valve body.

Working condition

‌closed state : when the screw stops rotating, the nut moves along the screw axis under the action of spring force (if designed) or gravity until it is tightly fitted to the screw. At this time, the through hole is completely closed, thus effectively preventing the flow into or out of the fluid.

‌open state : When the screw begins to rotate, the nut is driven away from the screw, and the through hole is gradually opened to allow the fluid to pass smoothly. The speed and direction of rotation determine the distance the nut moves, which in turn controls the degree of opening of the through hole.

Flow control
The screw valve is unique in its ability to precisely control the flow of fluid. By precisely adjusting the rotation speed and direction of the screw, the nut movement distance along the screw axis can be fine-adjusted, so as to achieve the precise control of the opening degree of the through hole. This control method makes the screw valve especially suitable for situations where the fluid flow needs to be carefully regulated.

Sealing performance
Screw valves also perform well in sealing performance. It usually adopts a metal-to-metal sealing method, and ensures the tight fit of the sealing surface through high-precision processing and matching. This design not only improves the reliability of the seal, but also effectively avoids the problem of fluid leakage under high pressure or high temperature environment.

Application field
With its simple structure, easy operation, good sealing performance and accurate flow control advantages, screw valves are widely used in petroleum, chemical, pharmaceutical, food and other industrial fields of fluid control system. It is not only one of the key equipment to achieve accurate fluid control, but also an important part of ensuring the safety and stability of industrial production.