AR21040 | Mini-Matic 4/B Valve 2.1mm Adjustable Injector 2600

AR21040 | Mini-Matic 4/B Valve 2.1mm Adjustable Injector 2600

AR21040 – Mini-Matic 4/B Unloader Valve 2.1mm Adjustable Injector – 2,600 PSI
The Annovi Reverberi AR21040 Mini-Matic 4/B Unloader Valve is a versatile, compact, and highly reliable
component for pressure washer systems that need both adjustable performance and built-in chemical
injection. Rated up to 2,600 PSI and supporting 3.0–4.0 GPM, it provides
precise pressure control, dependable bypass protection, and integrated soap/chemical injection in one
space-efficient package.

Engineered to protect the pump, the AR21040 diverts water into bypass when the spray trigger is released,
preventing damaging overpressure and heat buildup. At the same time, its adjustable 2.1 mm orifice
lets operators fine-tune output for different cleaning tasks. The integrated downstream injector enables
detergent application only at reduced pressure, ensuring safe, controlled soap delivery without exposing
pump internals to aggressive chemicals.

This combination makes the AR21040 especially popular with contractors, facility maintenance crews, and
professional cleaners who want system protection, detergent injection, and adjustable performance in one
rugged component.

Key Features

• Pressure rating: Up to 2,600 PSI.
• Flow range: Configured for 3.0–4.0 GPM systems.
• Valve type: Mini-Matic 4/B unloader with adjustable 2.1 mm orifice.
• Integrated injector: Built-in downstream chemical injector for soap/detergent application.
• Connections: 1/2″ FNPT inlet and 3/8″ MNPT outlet for easy plumbing into most washers.
• Construction: Brass housing with corrosion-resistant internal seals and components.
• Function: Combines pressure regulation, automatic pump bypass, and detergent injection.
• Typical use: Light industrial, commercial, and professional pressure-washing systems.

Adjustable Orifice for Precision Performance

The 2.1 mm adjustable orifice allows operators to dial in the exact pressure and flow needed for
each job, helping reduce system strain and improve cleaning efficiency. Ideal for:

• Fleet and vehicle washing.
• Cleaning construction and rental equipment.
• Maintaining commercial buildings and storefronts.
• Rinsing more delicate siding, roofs, or painted surfaces.

By matching output to the application, the AR21040 helps extend pump life and deliver more consistent
cleaning results.

Integrated Chemical Injector

Unlike separate injector kits, the AR21040 includes a built-in downstream chemical injector:

• Safe for pumps: Injector activates only in low-pressure mode, keeping chemicals out of the pump head.
• Simplified plumbing: Fewer separate components and potential leak points.
• Controlled application: Efficient detergent draw with proper dilution and easy switching between soap and rinse.
• Time-saving: No manual swapping between high-pressure cleaning and chemical application hardware.

Installation Guidelines

• Ensure the system is fully shut down and depressurized before installation.
• Connect the 1/2″ FNPT inlet and 3/8″ MNPT outlet into the pressure washer plumbing.
• Route the bypass line directly back to the pump inlet or a water tank; never cap or restrict the bypass line.
• Attach the soap/chemical supply line to the integrated injector port as specified by your system layout.
• Use a pressure gauge on the outlet to set working pressure via the top-mounted adjustment knob.

The AR21040 is designed for straightforward installation and quick adjustment, making it user-friendly
for repair shops, contractors, and DIY operators.

Typical Applications

• Contractor rigs: Portable or trailer-mounted washers with frequent chemical application.
• Fleet & vehicle washing: Buses, trucks, delivery vans, and heavy equipment.
• Facility maintenance: Schools, warehouses, garages, and public buildings.
• Light industrial cleaning: Food prep zones, machinery, and small production spaces.
• Residential contractors: Siding, roof, and deck cleaning where quick soap/rinse cycles are needed.

AR21040 | Mini-Matic 4/B Valve 2.1mm Adjustable Injector 2600

• 3-in-1 functionality: Pressure regulation, pump protection, and detergent injection in one unit.
• Compact design: Saves space versus separate unloader and injector assemblies.
• Durable build: Brass body and high-quality seals for long service life and corrosion resistance.
• Easy adjustments: Integrated control knob lets operators fine-tune pressure for each task.
• Reduced downtime: Simple plumbing, minimal maintenance, and fewer parts to stock or service.

Specifications

• Model: AR21040 Mini-Matic 4/B
• Maximum pressure: 2,600 PSI
• Flow rate: 3.0–4.0 GPM
• Orifice size: Adjustable 2.1 mm
• Inlet: 1/2″ FNPT
• Outlet: 3/8″ MNPT
• Bypass: Automatic flow diversion to protect pump and system components
• Injector: Built-in downstream soap/chemical injector
• Construction: Brass housing with corrosion-resistant internal components

Bottom line: The AR21040 Mini-Matic 4/B Unloader Valve is an ideal choice for operators who
need flexibility and efficiency. Its adjustable orifice, integrated injector, and rugged design streamline
cleaning workflows while keeping pumps safe from overpressure—making it a smart, space-saving upgrade for
professional contractors and facility maintenance crews alike.