The major function of solenoid valves is to control fluids flow automatically. They are becoming popular and used in various types of plants and equipment. The variety of designs is also a major reason these valves are used because you can choose a suitable vale for the application. But before you choose the type of solenoid, it is important to gather enough information regarding the application and what type of solenoid valve will suit it better, like a 2-way valve or 3-way valve. After you determine certain parameters of the solenoid valve, you can easily decide which type will be the most appropriate for your application. It is easier to do some online searching, gather the necessary data, then search for your required products on some online shops using the parameters or data you gathered. This will help you make an effective purchase decision.
Important Factors You Need to Check
- You need to make sure to use solenoid valves with clean liquids or air because solenoid valves are highly sensitive to dirt.
- If the solenoid valves are indirectly controlled, they would need a permanent pressure differential of o.5 bar for functioning properly. Therefore, it is not appropriate to use indirect operated valves in a closed system with low inlet pressure. When the 2-way valves are operated directly or semi-directly, the pressure differential would be 0 bar.
- Ensure that the medium and temperature being used are compatible with the material of the valve, for example, the seal and the body material.
- Beware of the fact that solenoid valves are quick to close and open. If you use them improperly, this can lead to pressure transients in the system, in other words, known as water hammers.
- Be sure to match the type of the solenoid valve with its application.
- Protection classification is also a necessary factor to be considered.
- The switching function, whether it’s closed or open, also matters.
- Consider the connection type.
- Check for the available electrical power and the one suitable for functionality.
- Select the solenoid valves based on the fluid flowing through them.
Principle of Operation
Solenoid valves can be differentiated into many types based on their principle of operation. They are:
- Direct operated
- Semi-direct operated
- Indirect operated.
Selecting the right operation principle is very crucial. Direct-operated valve function from 0 bar. Inside the valve, a small-sized orifice is closed off using a plunger with a gasket made of polymer. If the solenoid is energized using electricity, the electromagnetic force lifts the plunger, opening the valve. This principle is most appropriate for small valves and low flow rates.
Semi-direct operated solenoid valves are used for larger flows and valves than the direct-operated ones. Based on this principle, they can use medium pressure to open and close the valves. The semi-direct valves operate from 0 bar and have an enormously powerful coil.
Indirect operated valves are also suitable for larger flow rates and are operated from 0.5 bar for proper functioning. However, they have a less powerful coil than the semi-direct operated valves. They may have a small coil, but they can control larger flow rates with a small coil and consume less energy than the direct operated and semi-direct operated solenoid valves.
The circuit function indicated what type of function the valves have. Some of the important circuit functions are as follows:
2/2 Way Valves
A 2/2-way approach that the valve has two ports (inlet and outlet port) and positions (open and closed). Most of the two/2-way control valves are usually closed (or NC). This method that the valve is closed while now not powered and opens as soon because the coil is electrically energized. A usually open solenoid valve works the other manner: the valve is open when de-energized and closed while the coil is electrically energized. The maximum 2/2-manner valves can be used in only one route of waft. This is commonly indicated by using an arrow at the housing.
A 3/2- way valve usually consists of three ports and two positions. These valves are commonly direct operated solenoid valves that are operated from 0 Bar. As we all know, just like the direct operated valves, they have small orifices and are only suitable for controlling small flow rates. If you need a valve for controlling larger flows and larger orifices, consider using a 3-way ball valve. In circuit functions, you will be given options to choose from, like the normally closed, normally open, diverted, and universal.