A solenoid valve controls the flow of fluid in a tube or duct. Different mechanisms are employed to regulate the media, meaning a variety of these valves to cater to the variations.
In addition to the designs, these valves come with different operating mechanisms. Here, we have a look at the 5 types of solenoid valves and their working principles.
- Direct Acting Solenoid Valve Manufacturers
These valve types employ the easiest to work. An immediate acting solenoid valve involves a plunger that closes a tiny orifice directly, without counting on another force.
These types of solenoid valves are fast acting. They are able to also operate under different pressures, from the best to the maximum allowable levels.
A variant of the direct acting valve is the 3 way 2 position solenoid valve. It operates identically to the 2/2 valve, with only dissimilarities in the manner it exhausts fluid. It could possibly do so by using a seal at the plunger top or bottom.
The use of direct acting solenoid valves includes advantages and disadvantages. These valves are fast acting and accurate. Another advantage is these valve types can work with different line pressures, from low to high.
The downsides of direct acting solenoid valves are mostly in their strength and size. As the valves rely upon the closing force provided by the solenoid coil, they often lot of current to control.
This often means large solenoid construction, the systems are large-scale.
- Pilot-Operated Solenoid Valve
Also called an indirect-operated, a pilot solenoid valve utilizes the pressure difference over the valve ports to close or open the orifice. The working of these kind of valves is somewhat more technical than that of direct acting valves and with some more parts.
Here is how the pilot solenoid valve works.
A diaphragm separates the inlet and outlet ports of these kind of solenoid valves. Over the diaphragm is a tiny hole tha allows the medium to flow in to the upper chamber. A little duct connects this chamber to the low-pressure port.
The system’s pressure and a tiny spring keeps the valve closed. If the solenoid is energized, the pilot orifice opens, creating the pressure in the top chamber to drop.
This results in the diaphragm lifting and the medium to now flow freely from the inlet to the outlet port.
The pressure chamber in a pilot-operated solenoid valve serves to amplify the closing and opening forces. This permits small solenoids to use a high-flow line.
Because of this amplification of pressures, this kind of solenoid valve mostly doesn’t require huge amounts of current to work.
Despite their powerful operation, pilot solenoid valves have several limitations. These are a one-way solenoid valve, with the capacity of regulating a medium that only flows in a single direction.
Pilot solenoid valves are also slower than the direct acting types, plus they minimum operating pressure level, unlike direct solenoid valves that could work with 0-bar circuits.
Pilot solenoid valves are well suited for systems with sufficient pressure differences, such as irrigation systems and car wash equipment.
They’re most commonly used in applications where flow rates or capacities are high. Included in these are systems that control the flow of water such as faucets.
- Two Way Solenoid Valves
These valve types use two ports to close or open the flow of fluid. A 2-way solenoid valve is classified as normally open up if the orifice allows media to flow when the coil is de-energized and normally closed if energizing the coil allows fluid to flow through either port. The NC or normally sealed solenoid valve is more prevalent than the NO type.
Two-way solenoid control valve systems where only release and restriction of media is necessary. Like for example , air compression machines and similar equipment.
- Three Way Solenoid Valve
A 3-way solenoid valve usually comes equipped with three ports and two different orifices. Both orifices open alternatively, in line with the state of the solenoid coil.
Typically, these valve types have two inlet ports with an individual outlet. When included in this design, a three way solenoid valve mostly mixes two different fluids.
Some three way solenoid valves utilize two outlets and a single inlet port. This kind of design allows the valve to control the flow of your medium in one of the outlet ports by directing it in to the other. 3-way solenoid valves come in common cookware including the household dishwasher.
- Four Way Solenoid Valve
This type of valve utilizes four ports; two pressure inlets and two exhaust outlets. 4-way valves are generally used to work double acting solenoid valve actuators.
The inlet ports provide incoming pressures to the actuator or cylinder, and the outlet pipes are exhaustive pressure openings.
Solenoid valves come in several types, with different working mechanisms and constructions.
The type to use is determined by many factors. Mainly, the required action dictates the look and working principle.
Direct acting and 2-way solenoid valves suit systems where only shut down is needed. Complex systems that mix or direct fluids require more than the easy action.
In those circuits, additional ports are needed.