Plastic Solenoid Valves
Plastic solenoid valves control the flow of gases or liquids through tubes, as regular valves do, but unlike other valves, plastic solenoid valves can be controlled remotely. Constructed from plastic materials, plastic
solenoid valves are primarily used in applications that require corrosion or chemical resistance. As one of the most common flow control valves, plastic solenoid valves are used in industries such as commercial, industrial and home tools and appliances. Rustproof, plastic solenoid valves are also widely used in sanitary applications as there are many FDA-approved plastic materials. Some of the most common plastics that plastic solenoid valves are formed from include PTFE, PVC, natural
polypropylene, CPVC and PVDF. Offering long service lives, low control power and compact designs, plastic solenoid valves are commonly used in applications including dishwashers, garden watering system, industrial water treatment systems, water filtration, dispensing, vending, irrigation systems, opening, shutting, batching and mixing. Additional industries that benefit from plastic solenoid valves include agricultural, food processing, aerospace, cooling and heating, personal hygiene and medical. With a wide range of sizes and various sealing materials, there are numerous maintenance-friendly plastic solenoid valve designs.
Operated electromechanically by a solenoid, which is a magnetized coil activated by electrical charges, plastic solenoid valves control the flow of gases or liquids precisely through targeted electrical charges, sensor cue or by hysteresis (device memory). Plastic solenoid valves may be either normally closed (NC) valves or normally open (NO) valves, but not both. In NC valves a plunging pin or rod within the valve is held blocking the passage of air or fluid by a solenoid coil; the air or fluid pressure coming into the valve helps keep the valve shut as long as the pin blocks the passage. NO 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. Plastic solenoid valve manufacturers make two general types of valves: direct-acting and pilot-operated. Direct-acting plastic solenoid valves have a plunger that is in direct contact with the in-flow opening in the valve body, or orifice. This plunger is used to open and close the orifice, which permits or hinders flow. The pilot-operated plastic solenoid valve works with a diaphragm rather than a plunger, using differential pressure to control the flow of gases or fluids. In pilot-operated valves there is a solenoid-operated vent which is opened to allow the pressure to equalize, permitting fluids or gases to flow through the diaphragm in the valve's larger chamber.