Automatic Control Valves

Automatic control valves regulate pressure, flow and liquid level in water distribution networks without requiring external electrical power. Driven entirely by the energy of the pipeline itself, a hydraulically operated control valve responds to changes in system conditions through a network of pilot valves and sensing lines that modulate the main valve opening in real time. This self-contained operation makes them highly reliable in remote locations, reduces maintenance requirements and eliminates the need for power supply infrastructure at every installation point.

The main valve body is a hydraulically operated globe valve with a diaphragm or piston actuator chamber. Opening and closing is controlled by pilot pressure applied above or below the actuator. The control function is determined entirely by the pilot arrangement: changing the pilot circuit changes the valve's behaviour without modifying the main valve body. This modularity allows a single valve to be reconfigured in the field as system requirements change.

Pressure reducing valves (PRVs) are the most common automatic control valve application in water distribution. A downstream-sensing pilot regulates the main valve to maintain a constant downstream pressure regardless of upstream variation or demand fluctuation. The A200 pressure reducing valve is suitable for district metering area (DMA) inlets, pressure zone boundaries, high-rise building supply and booster station outlets. The A203 adds an integral check function to prevent reverse flow at low-demand periods.

For reservoir and tank filling, level control valves respond to a float pilot or electronic solenoid signal to close as the liquid level rises. The A100 modulating float control valve provides smooth, non-slam closure that prevents the pressure transients associated with rapid valve shut-off. The A400 flow control valve maintains a constant flow rate regardless of pressure variation, protecting distribution mains from demand peaks and preventing over-delivery to storage structures.

Pump control valves (the A76D) protect pump stations from water hammer following pump trip. A slow-closing pilot circuit delays full valve closure long enough to prevent destructive pressure waves from propagating into the distribution main. Combined with the A300 slow-closing check valve, pump station valve arrangements can be designed to meet the most demanding surge analysis requirements.

All automatic control valves in our range are available in DN50 to DN600 with flanged PN10 or PN16 connections. We supply full pilot circuit documentation, pressure setting certificates and maintenance manuals with every order. Our technical team can advise on pilot selection, sizing and commissioning for new installations and for in-service upgrades to existing control valve arrangements.