RKA4037-VRT-PKG | Triplex Pump, 4.0 GPM 3700 PSI, VRT Unloader

RKA4037-VRT-PKG by Annovi Reverberi — Complete VRT Plumbed Belt Drive Triplex Pump Package | 4.0 GPM | 3,700 PSI | Bronze Connecting Rods | Forged Brass Manifold | 24mm Solid Shaft | VRT Unloader with Easy Start | Auto-Reset Thermal Relief | 14,800 Cleaning Units

The RKA4037-VRT-PKG by Annovi Reverberi is a complete, factory-assembled VRT plumbed triplex ceramic plunger pump package engineered for belt drive pressure washing systems requiring 4.0 GPM at 3,700 PSI with fully integrated pressure regulation, thermal protection, and the speed-control flexibility that only a belt-and-pulley drive layout delivers. Rated at 4.0 GPM and 3,700 PSI, the RKA4037-VRT-PKG delivers 14,800 cleaning units — through bronze connecting rods, solid ceramic plungers, a forged brass manifold, stainless steel valves, dual redundant packing, and a 24mm solid keyed shaft that accepts belt drive pulley systems for tunable operating speed across a wide range of engine and motor platforms. As part of Annovi Reverberi’s pump and unloader assemblies stocked and supported by WSHPWR, the RKA4037-VRT-PKG is the complete belt drive answer for OEM builders, contractors, and system integrators who need 3,700 PSI with the drive geometry and speed control that direct-drive packages cannot provide.

The RKA4037-VRT-PKG is a factory-engineered, factory-assembled, factory-tested complete system — designed by Annovi Reverberi in Modena, Italy and distributed across North America by AR North America. The VRT plumbed package format means the unloader is factory-plumbed with the bypass recirculation circuit, thermal relief valve, and all hardware connected and verified before shipment. Belt alignment, pulley sizing, and tension adjustment are handled by the installer for their specific drive configuration — everything else is already done. Protected by a 5-year US limited warranty and built to be fully rebuilt rather than replaced, the RKA4037-VRT-PKG is a decade-of-service investment in a complete belt drive package.

Everything in One Box — The RKA4037-VRT-PKG Complete VRT Plumbed Package

Factory-Plumbed. Factory-Tested. Belt Drive Ready. Nothing Left to Source.

Open the RKA4037-VRT-PKG box and find a complete, factory-plumbed, belt drive-ready installation:

• RKA4037 triplex ceramic plunger pump with 24mm solid keyed shaft — factory-tested and pre-lubricated with break-in oil. Bronze connecting rods, solid ceramic plungers, forged brass manifold, stainless steel valves, dual redundant packing — factory-installed and factory-verified. 24mm solid crankshaft accepts belt drive pulleys for speed-tuned operation across a wide range of engine and motor platforms.
• VRT external bypass unloader — factory-plumbed and pressure-set — the VRT unloader is factory-calibrated for the 4.0 GPM / 3,700 PSI duty point and plumbed into the complete bypass circuit before shipment. Smooth pressure regulation and controlled bypass from the first startup.
• Easy Start feature — at startup, the VRT bypass circuit opens and the pump starts against zero back pressure. The engine or motor engages freely without hydraulic resistance — a significant advantage in belt drive systems where startup torque loads the belt and pulleys. Once the drive reaches operating speed, the bypass closes and the system builds to 3,700 PSI. Easier starting, reduced belt stress, longer drive component life.
• Exterior bypass recirculation loop — factory-plumbed — the bypass recirculation circuit is factory-assembled and connected, providing controlled water flow during trigger-off intervals and protecting the pump from pressure spikes throughout the cleaning cycle.
• Automatic Thermal Relief Valve (TRV) — factory-installed in bypass circuit — the thermal sensing pill monitors bypass water temperature continuously. When bypass water reaches 124–145°F, the TRV opens automatically — hot water exits through the relief port, and ambient-temperature supply water flows in to replace it. When temperature returns to the safe operating range, the TRV closes automatically. No manual reset. No intervention. Full thermal protection at all times.
• Fittings and mounting hardware — every fitting and fastener required for integration onto contractor skids, trailer frames, OEM belt drive installations, and wash bay systems. Organized in the box.
• Chemical injector and suction hose — not included — the RKA4037-VRT-PKG delivers straight 3,700 PSI high-pressure water output. When detergent capability is required, a downstream chemical injector and suction assembly are sourced separately.
• Factory break-in oil — crankcase pre-filled. Oil sight glass and vented dipstick for ongoing monitoring.
• Operator’s manual and service schematics — complete installation, startup, operating, and maintenance procedures with Annovi Reverberi part numbers for every serviceable component.

Decoding the RKA4037-VRT-PKG

What Every Segment of This Annovi Reverberi Package Designation Tells You

• RKA — Pump series: RKA Series triplex plunger pump — Annovi Reverberi’s commercial belt drive and direct drive platform
• 40 — Flow rate: 4.0 GPM
• 37 — Maximum pressure: 3,700 PSI — 4.0 × 3,700 = 14,800 cleaning units
• VRT — Unloader family: VRT Series external bypass unloader — factory-plumbed with Easy Start, bypass recirculation loop, and auto-reset TRV thermal protection
• PKG — Complete VRT plumbed package: pump plus fully integrated VRT plumbing assembly — everything in one factory-assembled, factory-tested box

24mm Solid Shaft — The Belt Drive Advantage

Speed Control via Pulley Ratio. Cooler Operation. Tunable Performance for Custom Builds.

The RKA4037-VRT-PKG‘s 24mm solid keyed shaft is the specification that separates this package from direct-drive alternatives — and for OEM builders, system integrators, and contractors designing custom pressure washer builds, it opens capabilities that a fixed-speed direct-drive pump cannot offer:

• Speed control via pulley ratio — by selecting the appropriate pulley diameter combination, the installer can run the RKA4037-VRT-PKG below engine or motor speed. Running the pump at a lower RPM than the drive source reduces heat generation at the plunger-seal interface, extends seal and packing service life, and allows the drive system to operate at its most efficient speed point while the pump runs at its optimal duty point.
• Cooler operation under sustained load — belt drive systems thermally decouple the engine from the pump. An engine or motor running at high RPM for peak torque output can drive the RKA4037-VRT-PKG at a lower, cooler pump speed through the pulley ratio — extending service intervals on ceramic plungers, dual redundant packing, and stainless valve seats across demanding continuous-duty programs.
• Flexible drive platform — the 24mm solid shaft accepts belt drive pulleys for both gas engine and electric motor drive configurations. The RKA4037-VRT-PKG is not limited to a specific engine type or motor frame — any drive source with the appropriate pulley and belt arrangement can power this pump package.
• OEM and custom build standardization — contractors and OEM builders designing multi-unit belt drive systems can standardize on the RKA4037-VRT-PKG for consistent pump performance, identical service procedures, and uniform parts across every unit in the fleet or production run.

Key Specifications

RKA4037-VRT-PKG Technical Details at a Glance

• Flow Rate: 4.0 GPM (gallons per minute)
• Maximum Pressure: 3,700 PSI
• Cleaning Units: 14,800 (GPM × PSI)
• Drive Type: Belt drive and direct drive — 24mm solid keyed shaft
• Pump Type: RKA Series triplex ceramic plunger pump — smooth, low-pulsation output; approximately 93% volumetric efficiency
• Shaft: 24mm solid keyed crankshaft — belt drive pulley compatible
• Connecting Rods: Bronze — required specification for sustained 3,700 PSI continuous-duty operation
• Manifold: Forged brass — durability in continuous wet-service environments
• Plungers: Solid ceramic — wear resistance and stable long-term performance
• Valves: Stainless steel — consistent output and corrosion resistance
• Packing: Dual redundant — extended seal life and reduced rebuild intervals
• Volumetric Efficiency: Approximately 93%
• Lubrication: Oil-bath crankcase — stable lubrication and bearing life in belt drive duty cycles
• Unloader System: VRT external bypass — factory-plumbed, pressure-set, and verified
• Easy Start: Bypass-circuit zero-back-pressure startup — drive engages freely; system builds to pressure at operating speed
• Thermal Relief Valve: Auto-open/auto-reset at 124–145°F — thermal sensing pill; hot water exits, ambient supply water replaces; no manual reset
• Serviceability: Oil sight glass and vented dipstick
• Chemical Injector: Not included — straight 3,700 PSI water output
• Warranty: 5-year limited warranty — US-based coverage through Annovi Reverberi North America

The VRT Plumbed Package — Why Factory-Plumbed Changes the Installation Experience

Not Just Mounted. Plumbed. Tested. Ready to Run.

• Easy Start reduces belt and pulley startup stress — in belt drive systems, startup torque loads the belt, pulleys, bearings, and shaft at the moment of highest mechanical stress. The RKA4037-VRT-PKG’s Easy Start feature routes through the bypass circuit so the drive starts against zero hydraulic back pressure. Belt tension, pulley loading, and shaft stress at startup are reduced every time the system starts — extending belt service life and reducing drive component wear across the pump’s working lifetime.
• Auto-reset TRV protects the pump during extended belt drive idle intervals — belt drive systems are often used in applications where the engine or motor continues running during operator breaks, material handling, or positioning intervals. When bypass water reaches 124–145°F during these idle periods, the TRV opens, vents the heated water, and draws ambient supply water through the system to restore safe operating temperature — automatically, without stopping the engine or interrupting the work cycle.
• Factory-plumbed bypass loop eliminates field plumbing variability — the bypass recirculation circuit on the RKA4037-VRT-PKG is factory-assembled and verified. OEM builders and contractors integrating multiple units gain identical bypass circuit behavior across every installation — consistent performance, consistent service, consistent results.

Typical Applications

Where the RKA4037-VRT-PKG Delivers Best Results

• Contractor trailer and skid-mounted belt drive pressure washer builds — the RKA4037-VRT-PKG’s complete factory-plumbed VRT package and 24mm solid shaft support contractor builds where belt drive geometry, speed control, and drive flexibility are design requirements
• Fleet maintenance programs, municipal wash bays, and equipment depots — continuous-duty belt drive installations where the Easy Start feature, auto-reset TRV, and standardized VRT plumbing support high-cycle daily washing programs with minimal operator intervention
• Agricultural barn sanitation and heavy equipment washdown — belt drive agricultural systems where pump speed can be tuned via pulley ratio for cooler operation across extended seasonal washing programs
• Industrial plant wash systems, conveyor washdown, and machinery cleaning — belt drive industrial installations where the RKA4037-VRT-PKG’s 14,800 cleaning unit output and bronze rod construction meet sustained industrial demands
• OEM belt drive equipment builds requiring standardized, repeatable pump packages — production builders specifying consistent belt drive pump packages across multi-unit builds benefit from the RKA4037-VRT-PKG’s factory-verified VRT plumbing, identical component specification, and AR North America national parts availability

5-Year US Warranty, National Parts Availability, and Wholesale Pricing

Built in Italy. Belt Drive Ready. Backed for Five Years.

The RKA4037-VRT-PKG is protected by Annovi Reverberi’s 5-year limited warranty through the US-based warranty and service network administered by AR North America. Every internal wear component — ceramic plungers, bronze connecting rods, forged brass manifold seals and o-rings, stainless valve seats, VRT unloader service parts, dual redundant packing kits, and crankcase bearings — is stocked nationally through authorized AR North America distribution channels. Contractors, fleet operators, agricultural operations, industrial facility managers, OEM equipment builders, resellers, and volume buyers are invited to contact the WSHPWR wholesale team for pricing on the RKA4037-VRT-PKG and the complete WSHPWR pump package lineup. WSHPWR maintains one of the most complete Annovi Reverberi inventories available through any US web store — with thousands of products in stock and a continually expanding catalog.

14,800 Cleaning Units. 3,700 PSI. 4.0 GPM. 24mm Solid Shaft. Belt Drive. VRT Plumbed. Easy Start. Auto-Reset TRV. Bronze Rods. Everything in One Box.

Italian Engineering. Belt Drive Platform. Complete VRT Plumbed Package. 5-Year US Warranty.

Stop sourcing VRT plumbing components separately. Stop assembling bypass loops on the bench. The RKA4037-VRT-PKG is the complete Annovi Reverberi belt drive VRT plumbed package for contractors, OEM builders, fleet operators, agricultural teams, and industrial system integrators who need 4.0 GPM at 3,700 PSI with the drive flexibility of a 24mm solid shaft and zero installation surprises. Bronze connecting rods. Forged brass manifold. Dual redundant packing. 93% volumetric efficiency. VRT unloader factory-plumbed. Easy Start zero-back-pressure startup. Automatic thermal relief at 124–145°F. Every fitting and every bolt. Factory-tested. Pre-lubricated. Five-year US warranty. One box. Same-day install.

Volume buyers and OEM builders standardizing on the RKA4037-VRT-PKG across production runs can reach the WSHPWR wholesale team directly at wholesale@wshpwr.com to discuss pricing across the complete Annovi Reverberi pump package lineup.