The GR 20 S is Annovi Reverberi's pressure regulating control unit — a compact 1.2 kg module that combines a working pressure regulator, bypass control lever, and a glycerin-filled pressure gauge with color-coded dial into one assembly. It is factory-matched to AR DUE, AR 202, and AR 252 diaphragm pumps.

How does the bypass control lever work?

The bypass lever routes pump output either to the working line (regulated pressure) or back to the pump inlet (bypass/recirculation). This allows the operator to start the pump unloaded, switch between spray and recirculation modes without stopping the engine, and relieve pressure instantly for nozzle changes or hose disconnection.

What pressure range can the GR 20 S regulate?

The built-in pressure regulator is rated for a maximum working pressure of 20 bar (290 psi) with a maximum flow of 40 L/min (10.6 GPM). The glycerin-filled gauge dampens needle flutter from pump pulsations for a stable reading even at high stroke rates.

How is the unit installed on the pump?

The GR 20 S mounts directly to the pump discharge port. The 255 × 188 × 181 mm envelope houses the inlet, outlet, and bypass ports in a single cast manifold — no external plumbing between the regulator and gauge is required.