How to choose the right solenoid valve and how are solenoid valves classified?

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Su Yan, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

The selection of solenoid valves should first follow the four principles of safety, reliability, applicability and economy, and secondly, select according to the on-site conditions in six aspects (i.e., pipeline parameters, fluid parameters, pressure parameters, electrical parameters, action modes, and special requirements). Selection basis The selection of solenoid valves should first follow the safety, reliability and applicability in turn.

In principle, it can be divided into three categories: direct-acting rotten stove solenoid valves, step-by-step direct-acting solenoid valves, and pilot-operated solenoid valves. In general, the most commonly used are check valves, safety valves, directional control valves, speed control valves, etc.

The following figure is some classification of CKD solenoid valves, please refer to it.

CKD solenoid valve selection classification table.

The solenoid valve contains a closed cavity, the middle of the cavity is a piston, and the two sides of the cavity are two electromagnets, once the solenoid coil is energized, the valve body is attracted to the direction of the energized electromagnet by force; There are through holes at different positions in the cavity to connect different tubingTherefore, the part of the oil drain hole can be selected to be opened by controlling the movement of the valve body; Since the inlet hole is normally open, the movement of the valve body causes the hydraulic oil to enter the different drain pipesThe pressure of the oil pushes the piston of the cylinder, which in turn pushes the piston rod, which drives the mechanism. Using this principle, it is possible to control the movement of the machine by controlling the current and disconnection of the electromagnet.

Specific classification:The working principle of direct-acting solenoid valves: When energized, the solenoid coil generates electromagnetic force, directly sucks the spool, and the spool is displaced. When the power is off, the electromagnetic force disappears and the spool is reset by spring.

Working principle diagram of direct-acting solenoid valve:

Working principle of distributed direct-acting solenoid valve:It is a combination of direct-acting and pilot-operated principles. Normally closed--- when there is no pressure difference between the inlet and the outlet, the electromagnetic force directly opens the pilot hole after the energization, connects the main valve, and the piston is lifted upwards in turn, and the valve is opened; When the inlet and outlet reach the starting pressure difference, after the power is on, the electromagnetic force first opens the pilot hole, and the pressure in the upper chamber of the main valve piston drops, so that the pressure difference and electromagnetic force are used to pull the main piston, and the valve port is opened; When the power is off, the pilot hole is closed by the spring return, and the upper cavity of the main piston is pressurized, and the main piston is pushed to move downward, and the valve is closed.

Normally open is the opposite of normally closed.

Working principle diagram of distributed direct-acting solenoid valve:

3. Working principle of pilot operated solenoid valve:When the normally closed --- is energized, the electromagnetic force attracts the pilot hole valve core, the pilot hole is opened, and the pressure in the upper chamber of the main valve piston drops, and the upper and lower chambers of the main piston form a high pressure at the top and bottom, so that the pressure in the lower chamber pushes the main piston to open the valve; When the power is off, the spring force is reset to close the pilot hole, the upper cavity of the main piston is pressurized, and the upper and lower cavities of the main piston are formed with high and low pressure, and the medium pressure and spring force push the main piston, and the valve is closed. Normally open is the opposite of normally closed.

Working principle diagram of pilot operated solenoid valve:

Hello,The United States imported solenoid valve manufacturers - Keen Ke KNKEGlad for your question.

According to technical experts from solenoid valves imported from the United States, solenoid valves are divided into three categories in principle

1. Direct-acting solenoid valve

KNKE direct-acting solenoid valves.

Principle: When energized, the electromagnetic coil generates electromagnetic force to lift the closing part from the valve seat and the valve opens; When the power is off, the electromagnetic force disappears, the spring presses the shut-off against the valve seat, and the valve closes.

2. Step-by-step direct-acting solenoid valve

KNKE direct-acting solenoid valves.

Principle: Knke's step-by-step direct-acting solenoid valve is a combination of direct-acting and pilot-operated principle, when there is no pressure difference between the inlet and outlet, after the power is on, the electromagnetic force directly lifts the pilot valve and the main valve closure up in turn, and the valve opens. When the inlet and outlet reach the starting pressure difference, after the power is applied, the pressure of the lower chamber of the electromagnetic pilot valve and the main valve rises, and the pressure of the upper chamber decreases, so as to use the pressure difference to push the main valve upward; When the power is off, the pilot valve uses the spring force or medium pressure to push the shut-off and move down to close the valve.

3. Pilot solenoid valve

KNKE pilot operated solenoid valve.

Principle: When energized, the electromagnetic force opens the pilot hole, the pressure of the upper chamber drops rapidly, and a low and high pressure difference is formed around the closing piece, and the fluid pressure pushes the closing part to move upward, and the valve is opened; When the power is off, the spring force closes the pilot hole, and the inlet pressure quickly forms a low and high pressure difference around the closing valve through the bypass hole, and the fluid pressure pushes the closing part to move down and close the valve.

With oxygen sensor (transmitter), PID intelligent controller, and electric proportional control valve, the opening of the valve can be controlled according to the set oxygen content.

It is a two-position five-way solenoid valve with two solenoid valve coils. I don't know.

The one I asked earlier is a two-position 5-port valve, and a 3-position 5-port valve or a cylinder with a locking function is required to control where you want to stop. Both work better at the same time. The difference between the 3-position valve and the two-position valve is that there is an additional intermediate position, and the intermediate position is that the 4 holes are not connected to each other, which is equivalent to holding the gas in the cylinder, so it can be stopped, but because the gas is compressible and elastic, that is, when the inertia of the workpiece driven by the cylinder is too large, it still cannot be stopped very reliably, so it must be combined with the cylinder with the locking function to achieve this purpose.

This is called a two-position (three-way) five-way solenoid valve. 1 air intake, 2 air outlets, 2 mufflers.

If the cylinder is a single-acting type (the cylinder returns to a spring), then only one air outlet is needed, and the other normal air outlet is blocked with a bulk, which is called a two-position three-way solenoid valve. The air intake is energized, and the cylinder is extended; The power is off, and the gas is turned off, and the cylinder is reset.

The cylinder is a double-acting type (piston push type), and the on-off electricity is used to control the direction of the air source to make the cylinder extend or retract, which is called a two-position five-way solenoid valve.