AR20242G | Gymatic 3/B Unloader Valve GHT Inlet 3650 PSI Duty

Overview

The AR20242G is a factory-direct Gymatic 3/B bolt-on unloader valve from Annovi
Reverberi, engineered for professional high-pressure pump systems requiring stable pressure control and
safe bypass operation. Rated for 3,650 PSI and up to 5.5 GPM, this unloader is
designed to mount directly onto compatible AR pump manifolds and features an integrated internal bypass,
eliminating the need for external bypass plumbing.

The “G” in AR20242G designates the inclusion of a built-in pressure gauge port,
allowing the installer to thread in a gauge for real-time pressure monitoring, system tuning, and diagnostic
checks — a valuable feature for commercial contractors, rental fleets, and OEM skid builders who demand
precise system calibration and simplified service access.

How the AR20242G Works

Trapped-Pressure Unloader Operation

• When the spray gun is open, water flows through the unloader directly to the hose and nozzle, delivering
  consistent working pressure.
• When the trigger is released, the trapped-pressure mechanism instantly redirects flow through the
  unloader’s internal bypass, preventing dangerous pressure spikes in the pump head.
• The internal bypass design reduces plumbing complexity, minimizes leak points, and helps maintain cooler,
  more stable pump operation during idle/bypass cycles.

Integrated Gauge Port

• Equipped with a dedicated pressure gauge port, the AR20242G makes system calibration significantly
  easier compared to no-port unloaders.
• Ideal for tuning new builds, diagnosing nozzle wear, verifying unloader performance, and troubleshooting
  pressure-drop issues.
• Allows on-board pressure monitoring on skids, trailers, and fixed-mount systems without installing
  additional tees or manifolds.

Key Features & Construction

OEM Brass Body and Stainless Internals

• Durable brass body for corrosion resistance and long-term reliability in cold-water and hot-water
  washdown environments.
• Stainless-steel plunger and spring components provide consistent sealing and bypass response,
  supporting frequent trigger cycling.
• Molded pressure adjustment knob allows precise setting of working pressure up to the valve’s maximum.
• Compact and lightweight, making it suitable for both portable machines and stationary industrial skids.

Direct-Pump Mounting Design

• Designed to bolt directly to pump heads using supplied banjo bolt hardware and sealing washers.
• Compatible with AR pump families such as XM, XMA, XMV, XR, RK, RKA, RKV, RR, RRA, RRV.
• Ensures proper hydraulic alignment and bypass path integrity compared to universal inline unloaders.

Specifications

Technical Ratings

• Model: AR20242G – Gymatic 3/B unloader with gauge port
• Max Pressure: 3,650 PSI
• Flow Range: 3.0 – 5.5 GPM
• Inlet: 1/2″ FPT
• Outlet: 3/8″ MPT
• Bypass: Internal, no external bypass hose required
• Gauge Port: Threaded side port for pressure gauge installation
• Material: Brass body, stainless-steel internals, molded adjustment knob
• Temperature: Suitable for typical commercial pump operating temperatures
• Mounting Style: Direct manifold bolt-on
• Country of Origin: Italy

Recommended Applications

Commercial & Industrial Pressure Washing

• Ideal for trailer skids, wash bays, detail shops, and fleet-washing rigs where operators frequently cycle
  the spray gun.
• Suitable for equipment rental companies needing reliable, easy-to-service unloaders with built-in pressure
  monitoring capability.
• Useful in municipal, agricultural, and industrial maintenance departments wanting simplified diagnostics.

OEM & Custom-Build Integration

• The gauge port is highly beneficial for OEM production lines, reducing time spent calibrating
  each new machine.
• Recommended for pump combinations where pressure verification during maintenance is routine.
• Supports both cold-water and moderate hot-water systems when paired with compatible AR pumps.

Installation & Best Practices

Setup Tips

• Install using the correct banjo bolts, ensuring all sealing surfaces and O-rings are clean and properly
  seated.
• Attach a pressure gauge to the port and adjust working pressure gradually while monitoring rise and fall.
• Confirm that all hoses, guns, and nozzles are rated for at least 3,650 PSI.
• Periodically inspect the unloader for debris, sluggish bypass response, or drift in pressure setpoint.

Summary

The AR20242G unloader valve provides all the reliability and simplicity of the Gymatic 3/B
internal-bypass design while adding the critical advantage of a built-in pressure gauge port.
Offering up to 3,650 PSI and 5.5 GPM performance with direct AR pump compatibility, it’s a top choice for
commercial washers, industrial skids, equipment fleets, and OEM builders who demand both precision and
durability. If you need an unloader that simplifies plumbing, enhances diagnostics, and delivers stable
pressure control — AR20242G is the ideal upgrade.