Solenoid Control Valves
Flomatic Corporation manufactures Solenoid control valves that open full when the solenoid control is energized and closes drop tight when de-energized. The solenoid pilot valve introduces control water to the diaphragm chamber of the main valve for closure and exhaust control water from the diaphragm chamber to the open valve. The control fluid is usually water from the pipeline; however, a separate source of higher pressure may be used when desired.
A solenoid control valve is an electromechanical valve for use with liquid or gas. The valve is controlled by an electric current through a solenoid coil. Solenoid control valves may have two or more ports: in the case of a two-port valve the flow is switched on or off; in the case of a three-port valve, the outflow is switched between the two outlet ports. Multiple solenoid valves can be placed together on a manifold.
Water Solenoid Control Valves
Water solenoid control valves are the most frequently used control elements in fluidics. Their tasks are to shut off, release, dose, distribute or mix fluids. They are found in many application areas. Solenoid valves offer fast and safe switching, high reliability, long service life, good medium compatibility of the materials used, low control power and compact design.
Solenoid Control Valves : Automatic Control Valves
Besides the plunger-type actuator which is used most frequently, pivoted-armature actuators and rocker actuators are also used. Solenoid valves may use metal seals or rubber seals, and may also have electrical interfaces to allow for easy control. A spring may be used to hold the valve opened or closed while the valve is not activated.
This type of valve relies on a differential of pressure between input and output as the pressure at the input must always be greater than the pressure at the output for it to work. Should the pressure at the output, for any reason, rise above that of the input then the valve would open regardless of the state of the solenoid and pilot valve.
In some solenoid control valves the solenoid acts directly on the main valve. Others use a small, complete solenoid valve, known as a pilot, to actuate a larger valve. While the second type is actually a solenoid valve combined with a pneumatically actuated valve, they are sold and packaged as a single unit referred to as a solenoid valve. Piloted valves require much less power to control, but they are noticeably slower. Piloted solenoids usually need full power at all times to open and stay open, where a direct acting solenoid may only need full power for a short period of time to open it, and only low power to hold it.