Different types of normally open solenoid valve principle explained

For the time being, normally open solenoid valve has many models and roles, they play in all aspects of the effect, but they are only due to the different products are divided into numerous types, such as air conditioning normally open solenoid valve, zero pressure normally open solenoid valve, convex shaft normally open solenoid valve, etc., but in fact, can be classified categories are not many, one from its movement mode, only three categories, respectively: direct-acting, stepping and pilot. According to their own different can be further divided into other types, these are subdivided, but these different classifications in different aspects have very different principles and uses, so this issue to briefly explain this aspect of the content.

A, direct-acting normally open solenoid valve.

Working principle: flange type two-position two-way solenoid valve when starting, the solenoid coil will produce an electromagnetic suction force, the valve body will be lifted upward, thus separating the seal on the valve seat from the valve seat, thus opening the valve plate; when the power is cut off, the force of the electromagnetic wave will weaken, and the spool seal will also be affected by the elastic force, resulting in the closure of the valve seat. (As opposed to conventional).

Features: Suitable for zero pressure, negative pressure, pressure difference, and large valve diameter. Such as solenoid high pressure valve.

Second, step-by-step direct-acting normally open solenoid valve (i.e., reverse control)

It works on the principle of: direct drive and pilot combined, such as the American Standard stainless steel ball valve in the start, normally open solenoid valve will first open the secondary valve, the main valve at this time, the lower chamber pressure is greater than the upper chamber pressure, so as to open the valve under the action of high pressure and electromagnetic force; in the disconnection of power, the secondary valve will open the valve using the spring or medium pressure.

Features: At zero differential pressure or close to a certain pressure, the working pressure usually does not exceed 0.6 MPa, but due to the ratio of solenoid head work and large volume, so it needs to be installed vertically.

Third, guide type normally open solenoid valve

Working principle: In the starting process, through the high temperature normally open solenoid valve open, so as to quickly reduce the pressure in the upper chamber of the main valve, thus forming a pressure differential in the upper and lower cavities of the main valve, thus pushing the main valve closing element upward through the pressure of the medium, so as to open the valve; in the power failure, the elasticity of the spool will be closed, the inlet pressure of the medium will quickly flow from the throttle hole into the upper chamber of the main valve, resulting in a pressure differential in the upper chamber thus making the main valve closed.