AR20399 | Gymatic 3/B Unloader Valve Injector 3650 PSI Adjustable

Overview

AR20399 – Gymatic 3/B Unloader Valve with Adjustable Injector – 3,650–3,800 PSI
The Annovi Reverberi AR20399 Gymatic 3/B Unloader Valve with integrated adjustable chemical
injector is a premium safety and regulation component for professional pressure washer systems.
Rated for 3,650–3,800 PSI, this valve not only protects high-pressure pumps from
overload but also gives operators flexible, on-demand detergent delivery—making it one of the most
versatile unloaders in the Gymatic family.

Automatic Bypass Safety & Pump Protection

By automatically diverting water into bypass mode when the spray gun trigger is released, the
AR20399 prevents pressure spikes that can lead to premature pump wear, hose damage, or system
failure. This dependable bypass action safeguards critical components and provides a smoother,
safer operating experience on commercial-grade pressure washers.

Durable Construction for Professional Use

The AR20399 is built with reinforced housing and heavy-duty internal components to withstand the
rigors of continuous operation. Precision-machined brass and stainless internals deliver stable
pressure regulation, while high-quality seals and wear-resistant parts handle frequent exposure to
hot water, detergents, and caustic agents. This robust build allows the unloader to maintain
smooth performance across thousands of duty cycles in demanding environments.

Integrated Adjustable Chemical Injector

Unlike standard unloaders, the AR20399 includes a factory-integrated adjustable chemical injector.
This injector allows operators to siphon detergents, degreasers, or sanitizing solutions directly
into the water stream at controlled ratios. An easy-to-use adjustment dial lets users fine-tune
soap delivery for light rinsing, heavy degreasing, or specialty cleaning applications.

For contractors and service crews, this feature eliminates the need for separate downstream
injectors and simplifies setup. For repair shops and DIY users, the integrated design ensures that
chemical application is safe, efficient, and compatible with professional-grade pumps.

Installation & Pressure Adjustment

The AR20399 is engineered for straightforward installation in the field or workshop. It mounts
quickly to compatible Annovi Reverberi pumps and can be serviced with common hand tools.
Accessible adjustment points with screws and lock-nuts make it simple to fine-tune system
pressure within the 3,650–3,800 PSI range so operators can match output to the job at hand. Each
valve is factory-tested for reliability and arrives ready for integration into professional
pressure washer systems.

Shipping & Availability

As part of the AR North America stocked catalog, the AR20399 is generally available for rapid
fulfillment through established U.S. distribution channels. Most orders ship quickly via common
carriers, helping contractors and service centers minimize downtime when replacement or upgrade
components are needed.

System Compatibility

The AR20399 belongs to the Gymatic 3/B family, designed for high-demand, higher-pressure
applications. In the broader AR unloader lineup:

• M2 Minimatic unloaders regulate at lower pressures (approx. 2,600–2,900 PSI).
• C2 / Gymatic unloaders, including the AR20399, cover the higher 3,650–3,800 PSI range.
• VR series unloaders are engineered for compatibility with RR, XM, and RK pump models.

The AR20399 is compatible with many AR pump families stocked by AR North America and can be
cross-referenced on the manufacturer’s support resources for detailed pump fitment information.

Key Benefits

• Automatic bypass safety prevents overpressure when the spray gun trigger is released.
• Integrated adjustable chemical injector for controlled soap or chemical draw.
• Precision-machined brass and stainless internals for long service life.
• Rugged construction handles hot water, detergents, and caustic agents.
• User-friendly design for easy installation, adjustment, and servicing.
• Factory-tested performance for reliable operation at rated PSI.

Typical Applications

• Contractor cleaning rigs – mobile wash trailers, fleet wash systems, and heavy-duty commercial washers.
• Repair shops & service centers – versatile replacement valve for high-demand AR pumps.
• Facility cleaning systems – warehouses, factories, and municipal wash-down setups.
• DIY and retail users – consumer-ready option with integrated injector, reducing add-on parts.
• Sanitation and disinfecting systems where chemical application and pressure control are both required.

Conclusion

The Annovi Reverberi AR20399 Gymatic 3/B Unloader Valve with Adjustable Injector
delivers two essential functions in one rugged unit: safe bypass protection for pumps operating up
to 3,800 PSI and adjustable chemical injection for detergent delivery. With its durable
construction, simple installation, and integrated injector design, it is a go-to solution for
contractors, repair shops, facility managers, and advanced DIY users. By combining
professional-grade safety with flexible chemical control, the AR20399 helps extend pump life,
simplify system plumbing, and improve cleaning efficiency in professional and commercial settings.