Solenoid valve function explained.

2/2 Failsafe Closed / Normally Closed, require power to Open.

2/2 way 2 ports (1 inlet and 1 outlet)

Zero-rated or direct acting solenoid valves, operate from vacuum up to the valve maximum working pressure. Also known as kick pilot, assisted lift or hung diaphragm valves.

Servo assisted or pressure assisted solenoid valves, operate using pressure difference between inlet and out ports, typically 7psi or 0.5 Bar. The pressure difference is used to lift the piston or diaphragm. Also known as pilot assisted, internal pilot, floating diaphragm or floating piston valves.

2/2 Failsafe Open / Normally Open require power to Close.

Zero rated or direct acting solenoid valves - operate from vacuum up to the valve maximum working pressure. Also known as kick pilot, assisted lift or hung diaphragm valves.

Servo assisted or pressure assisted solenoid valves - operate using pressure difference between inlet and out ports. Typically, require a guaranteed 7psi or 0.5 Bar higher inlet pressure than outlet pressure. Also known as pilot assisted, internal pilot and floating diaphragm valves.

2/2 way Latching require only a short pulse to Open or Close.

Latching solenoid valves - also known as bi-stable valves.

Require a very short electrical low voltage 6 volt; 9 volt; 12 volt or 24volt DC (direct current) power pulse to open, and the valve will stay open even without more power being applied.

A reverse polarity power pulse will close the valve and will stay closed until the cycle is repeated.

Excellent choice for energy saving, battery operated, solar-powered applications or where low heat generation from coil is required.

3/2 way, 3 ports (1 inlet and 2 outlets) for diverting flow.

3 way solenoid valves can be direct acting or pressure assisted, with either 2 ports in the base and a third (exhaust) port at the top through the coil, all three ports at the base or opposing two ports on one side and one port opposite.

These are the functions typically available for 3 way valves, these being normally closed, normally open or universal function. Please see the explanation below, which better explains the function of a 3 way solenoid valve.

3/2 Way Normally Closed

Power Off (De-energised) - inlet port is closed, outlet port open through to 3rd exhaust port.

Power On (Energised) - inlet port opens allowing flow through to outlet port and exhaust port is closed.

3/2 Way Normally Open

Power Off (De-energised) - Typically inlet port (top) is open to flow through outlet port and exhaust port is closed.

Power On (Energised) - inlet port (top) closes, outlet port opens to flow through exhaust port.

3/2 Way Universal

Flow can be in any direction, so according to how the valve is connected to the pipework it can be operated as a normally closed, normally open or for diverting flow in both directions.

5/2 way 5 ports 2 positions single acting / mono stable.

5/2 way single acting with spring return, (1 inlet, 2 outlets and 2 exhaust ports).

Example: Power to coil Cylinder fully extends - Power off cylinder fully retracts (or vice versa)

5/2 way 5 ports 2 positions, double acting (twin coil)

Example: Power to left coil Cylinder fully extends, power to right coil cylinder fully retracts, power off cylinder stays put fully extended or retracted.

5/3 way 5 ports 3 positions.

5/3 way double acting (twin coils)

Example: Power to left coil cylinder extends, power to right coil cylinder retracts, power off cylinder stays put even in a mid-position.

Valve Search Wizard.

Try our Solenoid Valve Search Wizard by function (2/2 3/2 5/2 5/2 way - direct acting pressure assisted or latching), body material (brass, stainless, plastic).

The simple way to find what you are looking for, or just enter the part number in the "search for products" tab from the brand you have at, let the store do the rest.