Description
1" Latching Irrigation Solenoid Valve – PN22508AL
The PN22508AL is a 1" latching / bi-stable irrigation solenoid valve designed for battery-powered, remote and energy-efficient water control systems. Unlike a conventional continuously energised solenoid valve, it requires only a short DC pulse to change position, then remains open or closed without continuous electrical power.
Featuring a 25mm flow orifice, heavy-duty glass-reinforced UV-resistant PA66 body and integrated flow controller, the PN22508AL is designed for agricultural irrigation, sprinkler systems, landscaping, greenhouse watering and remote water-control installations.
Anti-water hammer operation, manual override and an external bleed screw with removable metering pin provide reliable operation together with straightforward adjustment and maintenance.
Valve Function & Operation
Function: 2/2 way latching / bi-stable
Operation: Servo / pressure assisted
The PN22508AL requires a minimum pressure differential across the valve for reliable operation.
Minimum differential: 0.65 Bar
Working pressure: 0.65 to 10 Bar
Unlike the standard PN22508A, electrical power does not need to remain applied while the valve is open.
Latching / Bi-Stable Control
The valve changes state using a short 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.
This significantly reduces electrical consumption and makes the PN22508AL particularly useful for battery, solar and remote irrigation control systems.
Port & Flow Performance
Port: 1" BSP
Optional: 1" NPT
Orifice: 25mm
Water flow: 126.9 L/min at 1 Bar pressure drop
Low-Power Latching Coil
Coil type: Bi-stable / latching
Power: 2.2 Watts
Supply: 6–40V DC
Pulse duration: 20–100 milliseconds
Capacitor: 4700µF required
Protection: IP66
Connection: 30cm flying leads
The coil requires power only during the switching pulse rather than continuously while the valve is held open.
Polarity Reversal
Valve switching is achieved by reversing the polarity of the DC pulse.
Open pulse → + / - polarity
Close pulse → reverse polarity
The controller therefore needs to provide the required short pulse and reverse the positive and negative connections for the opposite valve state.
A 4700µF capacitor is required in the control circuit.
Integrated Flow Controller
The built-in flow controller allows the water flow through the valve to be manually adjusted.
This is useful for balancing individual irrigation zones, regulating sprinkler output and controlling excessive flow without installing a separate flow-control valve.
Anti-Water Hammer Design
The diaphragm arrangement provides controlled valve operation to help reduce hydraulic shock when the water supply is switched.
This helps protect irrigation pipework, pumps, fittings and associated equipment from repeated water hammer and pressure surges.
Manual Override & External Bleed
A manual override allows the valve to be operated locally during commissioning, testing or maintenance.
The external bleed screw incorporates a removable metering pin, allowing the pilot passage to be cleaned without complete valve disassembly.
This is particularly useful in irrigation systems where sediment and small particles may be present in the water supply.
Construction & Materials
Body: Glass-reinforced PA66
Properties:
UV resistant
Corrosion resistant
Internals:
Stainless steel
Seals:
NBR
The reinforced engineering plastic construction provides a lightweight and corrosion-resistant valve suitable for outdoor irrigation installations.
Media & Temperature
Media: Water
Maximum media temperature: +60°C / 140°F
Typical Applications
Battery-powered irrigation
Solar-powered irrigation
Agricultural irrigation
Automatic sprinkler systems
Remote watering systems
Landscape irrigation
Greenhouse watering
Underground irrigation
Irrigation control systems
Low-power water automation
PN22508A or PN22508AL?
PN22508A → Normally Closed
Conventional AC/DC solenoid valve requiring continuous coil power to remain open.
PN22508AL → Latching / Bi-Stable
Uses a short DC pulse to change position and requires no continuous holding power.
For remote or battery-operated irrigation, the PN22508AL is therefore the more energy-efficient option.
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