Description
2" Latching Irrigation Solenoid Valve – PN22520AL
The PN22520AL is a 2" latching / bi-stable irrigation solenoid valve designed for high-flow, battery-powered and low-energy water control systems. A short DC electrical pulse changes the valve position, after which it remains open or closed without continuous electrical power.
Featuring a large 50mm flow orifice providing 668 L/min water flow, the PN22520AL is well suited to large agricultural irrigation zones, sprinkler systems, landscaping and remote water distribution. Its heavy-duty glass-reinforced UV-resistant PA66 body provides a lightweight and corrosion-resistant alternative to conventional metal irrigation valves.
The valve also incorporates anti-water hammer operation, manual override and an external bleed screw with removable metering pin, simplifying manual operation and maintenance.
Valve Function & Operation
Function: 2/2 way latching / bi-stable
Operation: Servo / pressure assisted
Minimum pressure differential: 0.65 Bar
Working pressure: 0.65 to 10 Bar / approximately 150 PSI
The pressure-assisted diaphragm design uses the water pressure differential to operate the large 50mm main flow passage.
Unlike a conventional normally closed solenoid valve, the PN22520AL does not require continuous electrical power to maintain its switched position.
Latching / Bi-Stable Operation
The PN22520AL changes valve position using a short DC electrical pulse.
Pulse in one polarity → Valve opens
The valve then remains open without power.
Reverse polarity pulse → Valve closes
The valve then remains closed without power.
Only a short pulse is required each time the valve changes state, making this design particularly suitable for battery, solar and remotely powered irrigation controllers.
Port & Flow Performance
Port: 2" BSP
Optional: 2" NPT
Orifice: 50mm
Water flow: 668 L/min at 1 Bar pressure drop
Low-Power Latching Coil
Coil type: Latching / bi-stable
Power: 2.2 Watts
Supply: 6–40V DC
Pulse duration: 20–100 milliseconds
Required capacitor: 4700µF
Protection: IP66
Connection: 30cm flying leads
The low-power latching design means the coil consumes electrical energy only while the switching pulse is being applied.
Polarity Reversal Control
Opening and closing are achieved by reversing the polarity of the DC pulse.
Open → pulse in one polarity
Close → reverse polarity pulse
The irrigation controller must therefore provide a short DC pulse and reverse the positive and negative connections to switch the valve back to its opposite position.
A 4700µF capacitor is required in the control circuit.
Why Use a Latching Irrigation Valve?
For a large 2" irrigation valve, the ability to maintain position without continuous coil power can be particularly useful.
The PN22520AL is well suited to installations using:
Battery-powered controllers
Solar-powered controllers
Remote irrigation stations
Off-grid watering systems
Low-energy control systems
Once switched, no continuous holding power is required until the next valve command.
Anti-Water Hammer Design
The PN22520AL incorporates an anti-water hammer design to help reduce hydraulic shock when controlling high water flow rates.
This is particularly important with a 50mm orifice and approximately 668 L/min flow capacity, where rapid changes in water velocity can otherwise create substantial pressure surges within the irrigation system.
Manual Override & External Bleed
An integrated manual override allows local operation during commissioning, maintenance or controller failure.
The external bleed screw incorporates a removable metering pin, allowing the pilot passage to be cleaned without completely dismantling the valve.
This can be particularly useful in agricultural water systems where sediment or small particles may enter the irrigation supply.
Construction & Materials
Body: Glass-reinforced PA66
Properties:
UV resistant
Corrosion resistant
Internals: Stainless steel
Seals: NBR
The reinforced engineering-plastic construction provides good mechanical strength while considerably reducing weight compared with a conventional 2" metal-bodied irrigation valve.
Media & Temperature
Media: Water
Maximum media temperature: +60°C / 140°F
Typical Applications
Agricultural irrigation
High-flow sprinkler systems
Battery-powered irrigation
Solar-powered irrigation
Large irrigation zones
Remote watering systems
Sports ground irrigation
Landscape irrigation
Greenhouse watering
Underground water systems
PN22520A or PN22520AL?
PN22520A → Normally Closed
Conventional AC/DC solenoid version requiring continuous electrical power to maintain the energised open position.
PN22520AL → Latching / Bi-Stable
Requires only a 20–100ms polarity-controlled pulse to change state and then remains in that position without continuous coil power.
For remote, battery or solar-powered irrigation, the PN22520AL is therefore the better choice.
Related Products & Categories
