what exactly is a Solenoid Valve?Solenoid valves are devices electromechanically operated with the use of a solenoid to change the state of a valve from open to close to control the flow liquid or gas.Solenoid valves can be categorized into five groups. To let you understand easier, we make it an infographics as belowCheck more details “A Definitive Guide to Choose a Right Solenoid Valve”
Five types of solenoid valve
- Two-Way Valves:They consist of two ports way which is alternately used to permit inflow as well as shutting it off. A two-way valve can be classified to be normally open or normally closed in its operation. These valves are very versatile and can be deployed in a wide variety of applications in many industries to simply switch flow on and off and with a normally open valve, the valve remains open until current is applied to close the valve.
- 2/2 Direct Operated or Direct Acting Valve: The solenoid valves have the most working simple principle. In a direct acting valve, when the valve opens, the coil magnetically acts in a direct action, lifting the shaft and the seat of the valve without depending on outside pressure. It simply means that by energizing the solenoid coil, there is a direct influence on the position of the valve. And one basic function of a direct acting valve is that when the valve is always fully operational without the need for any pressure in the line.
- 2/2 Semi-direct operated solenoid valves refer to tameson combine the properties of direct and indirect valves. This allows them to work from zero bar, but still they can handle a high flow rate. They look somewhat like indirect valves and also feature a movable membrane with a small orifice and pressure chambers on both sides. The difference is that the solenoid plunger is directly connected to the membrane. When the plunger is lifted, it directly lifts the membrane to open the valve. At the same time, a second orifice is opened by the plunger that has a slightly larger diameter than the first orifice in the membrane. This causes the pressure in the chamber above the membrane to drop. As a result, the membrane is lifted not only by the plunger, but also by the pressure difference. This combination results in a valve that operates from zero bar, and can control relatively large flow rates. Often, semi-direct operated valves have more powerful coils than indirect operated valves. Semi-direct operated valves are sometimes called assisted-lift solenoid valves.
- 2/2 Indirect or Pilot-Operated Valves:The pilot operated valves, acts as a pilot to assist with the operation of the valve when the plunger opens up the pilot opening, the built-up pressure causes the valve to open and close. The indirect valve needs to maintain full power in order to remain in an open state, and perform at a slower rate. Pilot-operated valves only need full power when opening the valve, as they can hold their open position even when operating on low power. The main function of this valve is that it requires less electrical energy to operate.
- Three-Way Valves: This valve is used to operate single-acting actuators and comes with three ports, with port 1 as the valve inlet, port two as the outlet and port 3 as the exhaust. They are commonly used when alternate and exhaustive pressure from the diaphragm operator of a control valve and can be mostly categorized as Normally Closed, Normally Open or Universal for diverting functions based on the valve condition when the solenoid is energized.
- Four-Way or Five way Valves:These valves can have four or more port connections and provide a positive two directional action. Four-way valves are commonly used to provide on-off operation of double-acting valves with a dual-acting cylinder or actuator. When the solenoid is de-energized, it sends the full air supply to one side of the actuator and exhausts the other side to the atmosphere.
