3 Way Solenoid Valves
A 3 way solenoid valve is a type of flow control valve that has three connections and two orifices. Most 3 way solenoid valves are manufactured for air and gas flow regulation, which results in mostly
pneumatic valves; however, hydraulic 3 ways solenoid valves are also available. Three way solenoid valves are powered by natural pressure and electromagnetic force; having fewer moving parts is considered good design, since moving parts require maintenance. 3-way solenoid valves are also easily operated by remote devices that activate the solenoid coil, making 3 way solenoid valves extremely useful for operating potentially dangerous machinery or inaccessible lines. The most common application for three way solenoid valves is applying pressure to and exhausting pressure from either a valve actuator or a single acting cylinder. Other applications for 3-way solenoid valves include mixing, diverting and venting for various types of machinery and equipment. A long list of industries that benefit from the use of 3-way solenoid valves include climate control, paintball, medical, semiconductor, HVAC, analytical instrumentation, food and beverage, electronics and transportation. 3 way solenoid valves are commonly made from materials such as
stainless steel, ductile iron,
polypropylene, polystyrene, brass, copper, cast iron and PVC.
Operated electromechanically by a solenoid, which is a magnetized coil activated by electrical charges, three way solenoid valves control the flow of gases or liquids through targeted electrical charges, sensor cue or by hysteresis (device memory). 3-way solenoid valves may be either normally closed (NC) valves or normally open (NO) valves, but not both. In NC 3-way valves a plunging pin or rod within the valve is held blocking the passage of air or fluid by a solenoid coil. NO 3-way valves are the opposite; they remain open until the solenoid is activated and pushes down the plunger, blocking flow and creating pressure to keep the valve closed. 3-way solenoid valve manufacturers make two general types of valves: direct-acting and pilot-operated. Direct-acting plastic solenoid valves have a plunger that is used to open and close the orifice, which permits or hinders flow. The pilot-operated 3 way solenoid valve works with a diaphragm rather than a plunger, using differential pressure to control the flow of gases or fluids. Generally, 3-way solenoid valves are able to switch the outflow between two outlet ports; when one outlet is closed, the other is open. There are also 2-way solenoid valves and 4-way solenoid valves. A two-way solenoid valve uses one inlet and one outlet in order to permit and shut off fluid flow. A 4-way solenoid valve has four or five pipe connections featuring one pressure inlet, two cylinder ports and one or two outlets.