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- The Gymatic 3B unloader valve is a pressure-regulating “unloader” valve
used on high-pressure pumps from Annovi Reverberi (AR) — typically the RK,
XM, or XW pump series.
- Its main job: automatically relieve pressure inside the pump when the spray gun
trigger is released, preventing dangerous over-pressurization.
- When you stop spraying (trigger off), the unloader
activates — water is diverted via its internal bypass, so pressure in the
pump drops to near zero, but pressure remains “trapped” in the
high-pressure hose until the gun is opened again.
Additional
Features & Use-cases
- Built-in bypass channel — no need for an external bypass hose.
- Chemical injector (optional, depending on version) — some variants include a chemical injector that
lets you draw detergent or cleaning chemicals into the high-pressure
stream.
- Flow/pressure control — you can adjust the valve (spring tension) to set
the desired pressure output according to your pump’s rating. This ensures
stable spray pressure and protects the pump and other components
Typical Applications
- Use in pressure-washer systems (residential
or industrial) built around AR pumps: washing vehicles, cleaning concrete,
surfaces, etc. Because the unloader ensures safe, automatic pressure drop,
it lets you frequently start/stop spraying without damaging pump
internals.
- Use when you want to add detergent or cleaning
chemical along with pressurized water (for washing or cleaning
operations), for versions with injector.

