RKV4037VR35IDR | 3400 RPM Industrial Triplex Pump Package

RKV4037VR35IDR by Annovi Reverberi — RK Series Triplex Plunger Pump with Gymatic VR35 Unloader, Chemical Injector, and IDR Instant Dump Regulator | 4.0 GPM | 3,700 PSI | Bronze Connecting Rods | 1″ Hollow Keyway Shaft | Direct Gas and Diesel Engine Drive

The RKV4037VR35IDR by Annovi Reverberi is a high-output RK Series triplex ceramic plunger pump engineered for gas and diesel engine-driven commercial and industrial pressure washing systems requiring 4.0 GPM at 3,700 PSI with the elevated bypass regulation capacity of the Gymatic VR35 unloader, factory-integrated downstream chemical injection, and the additional operator safety feature of the IDR Integrated Dump Regulator. Rated at 4.0 GPM and 3,700 PSI at 3,400 RPM, the RKV4037VR35IDR delivers 14,800 cleaning units through a reinforced crankcase with oversized crankshaft, bronze connecting rods, solid ceramic plungers, precision brass manifold, stainless steel check valves, and a 1″ hollow keyway shaft for direct-drive coupling to gasoline or diesel engines.

The RKV4037VR35IDR is the most completely specified pump in the RKV 3,700 PSI family — combining the Gymatic VR35 unloader, active downstream chemical injector (I), and the IDR Instant Dump Regulator that immediately shifts the system to full bypass and dumps pressure the moment the spray trigger is released. This three-function assembly — pressure regulation, chemical injection, and instant pressure dump — provides a significant operational and safety advantage for systems that cycle frequently between wash and idle, multi-operator environments, and professional applications where eliminating trigger-release pressure spikes is a primary design requirement.

Built by Annovi Reverberi in Modena, Italy — with US-based operations, a domestic parts distribution network, and dedicated AR North America technical support — the RKV4037VR35IDR arrives as a complete, factory-tested assembly. Pre-filled with AR break-in oil, equipped with the factory-matched VR35 + IDR unloader assembly and active downstream chemical injector, and packaged with mounting bolts and fasteners, a vented dipstick, operator’s manual, and full parts schematic, this pump is ready to install from the moment it arrives. Protected by a 5-year US limited warranty through AR North America and built to be fully rebuilt rather than replaced, the RKV4037VR35IDR is a long-term investment capable of a decade of productive commercial service life.

Factory-Matched and Approved — The RKV4037VR35IDR Complete Assembly Advantage

No Mismatches. No Guesswork. No Warranty Risk. Just Install and Run.

Every RKV4037VR35IDR ships as a factory-matched, factory-approved, and factory-installed complete pump and unloader assembly — the Gymatic VR35, I-series downstream injector, and IDR Instant Dump Regulator all selected, calibrated, and installed by Annovi Reverberi as a validated system for this pump’s 4.0 GPM / 3,700 PSI operating point:

• Factory-matched VR35, injector, and IDR — the three-function control assembly on the RKV4037VR35IDR is not field-assembled from separately sourced components. The VR35 pressure regulation range, I-series injector draw characteristics, and IDR dump response timing are factory-calibrated to work together as a single coherent system at 4.0 GPM / 3,700 PSI — eliminating the integration variables that arise when these functions are installed separately.
• Factory-approved configuration — the complete RKV4037VR35IDR assembly is validated and approved by AR North America for this duty point. Operating with the factory-installed components maintains full 5-year warranty coverage. Warranty coverage is maintained by operating with factory-installed components.
• Factory-installed and tested — every RKV4037VR35IDR exits the AR manufacturing facility with the VR35 + IDR + injector assembly mounted, calibrated, and load-tested at 50%, 100%, and 150% of rated output. No field assembly, no calibration guesswork, no uncertainty about pressure dump timing or bypass response.
• Eliminates component mismatch returns — incorrectly specified or separately sourced dump regulator, unloader, and injector combinations are a leading cause of system performance problems on high-pressure builds. The factory-matched RKV4037VR35IDR assembly eliminates these failure modes before the pump leaves the box.
• Stress-free installation — mount the pump to the engine, connect system hoses, connect the detergent supply line to the injector port, add fuel, and start. The RKV4037VR35IDR arrives engineered, assembled, and ready for immediate field deployment.

The IDR Instant Dump Regulator — What It Does and Why It Matters

Instant Pressure Drop at Trigger Release. Safer Operation. Less Stress on Every Component.

The IDR (Integrated Dump Regulator) on the RKV4037VR35IDR is a critical safety and longevity feature that distinguishes this model from standard VR35-equipped pumps:

• Instant pressure dump at trigger release — when the spray gun trigger is released on the RKV4037VR35IDR, the IDR immediately shifts the pump to full bypass and dumps line pressure rather than holding residual pressure in the hose and gun. This instant dump eliminates the pressure spike that occurs on standard bypass transitions, removing a significant repetitive stress load from hoses, quick couplers, spray guns, and wand fittings across every trigger release cycle.
• Enhanced operator safety — immediate pressure drop at trigger release means no residual high pressure in the gun between passes, between surfaces, or during brief workflow pauses. On professional multi-operator systems and busy wash bays where gun handling changes hands, the IDR’s instant dump provides a meaningful safety margin compared to systems that retain line pressure after trigger release.
• Reduced component fatigue in high-cycle applications — mobile contractor rigs, fleet wash bays, and industrial wash operations that cycle the trigger gun dozens or hundreds of times per shift experience cumulative fatigue from repeated pressure transitions. The RKV4037VR35IDR’s IDR converts each trigger release from a pressure spike event to a controlled dump, reducing this cumulative fatigue across hose crimps, fitting threads, valve seats, and gun bodies throughout the system service life.
• Reduced pump thermal stress in high-idle applications — the IDR’s instant bypass transition minimizes the brief pressure-spike dead-heading event that generates heat at the pump head during trigger-off transitions. In systems that idle frequently between cleaning passes, this thermal reduction accumulates over a shift into measurably lower seal and valve operating temperatures.
• Ideal for systems with frequent trigger cycling — the RKV4037VR35IDR is specifically engineered for commercial applications where the trigger is cycled frequently: fleet wash bays, agricultural equipment cleaning, construction site washdowns, and mobile contractor rigs where operators start and stop flow repeatedly throughout a work day.

Decoding the RKV4037VR35IDR Model Number

What Every Segment of This AR Pump Designation Tells You

• RKV — Pump series: RK Series triplex plunger pump — AR’s industrial pump platform with reinforced crankcase, oversized crankshaft, and front-access piston packing and valve serviceability
• 40 — Flow rate: 4.0 GPM per AR model code convention
• 37 — Maximum pressure: 3,700 PSI per AR model code convention — 4.0 × 3,700 = 14,800 cleaning units
• VR35 — Unloader system: Gymatic VR35 — AR’s elevated-capacity Gymatic unloader rated to 4,000 PSI and 5 GPM. At 3,700 PSI the VR35 operates with 300 PSI of headroom below its rated ceiling — within the VR35’s rated envelope. Unloader part reference: AR22287.
• I — Chemical injector: Included — downstream soap and chemical injector factory-integrated into the Gymatic VR35 assembly, enabling low-pressure detergent application without a separate injector fitting
• DR — IDR Integrated Dump Regulator: instantly dumps pressure to bypass at trigger release, eliminating pressure spikes at trigger-off transitions and reducing cumulative stress on hoses, guns, and fittings throughout the system

Key Specifications

RKV4037VR35IDR Technical Details at a Glance

• Flow Rate: 4.0 GPM (gallons per minute)
• Maximum Pressure: 3,700 PSI
• Cleaning Units: 14,800 (GPM × PSI)
• Operating Speed: 3,400 RPM
• Pump Type: RK Series triplex ceramic plunger pump — smooth, low-pulsation high-pressure output
• Crankshaft: Oversized — engineered for the sustained mechanical demands of 4.0 GPM / 3,700 PSI continuous commercial duty
• Manifold Material: Precision-machined brass — corrosion-resistant construction for sustained 3,700 PSI cycle integrity
• Plungers: Solid ceramic — exceptional hardness, wear resistance, and thermal shock resistance
• Connecting Rods: Bronze — premium fatigue strength and wear resistance at 4.0 GPM / 3,700 PSI continuous duty
• Valves: Stainless steel check valves — pre-installed for reliable sealing under continuous high-pressure operation
• Drive Interface: 1″ hollow keyway shaft — direct-drive coupling to gas or diesel engine crankshaft
• Serviceability: Front-access piston packings and valve assemblies; oil sight glass and vented dipstick
• Lubrication: Oil-bath crankcase for continuous bearing and journal lubrication
• Unloader System: Gymatic VR35 (AR22287) — rated to 4,000 PSI and 5 GPM; 300 PSI operating headroom above 3,700 PSI; factory-matched and factory-installed
• Chemical Injector: Included — I-series downstream venturi injector factory-integrated into VR35 assembly
• IDR: Integrated Dump Regulator — instant pressure dump to bypass at trigger release; factory-installed and calibrated
• Warranty: 5-year limited warranty — US-based coverage through AR North America; maintained with factory-installed components

What’s Included in the Box

A Complete, Factory-Configured RKV4037VR35IDR Assembly Ready for Installation

• Factory-matched Gymatic VR35 unloader (AR22287) with I-series injector and IDR Instant Dump Regulator — selected, calibrated, and installed by AR North America as a complete three-function assembly for the RKV4037VR35IDR’s 4.0 GPM / 3,700 PSI operating point
• AR factory break-in oil — crankcase pre-filled to the correct operating level for first startup
• Vented dipstick — fast, accurate crankcase oil level checks with proper crankcase pressure relief
• Clear oil sight glass — at-a-glance visual verification of crankcase lubrication level
• Stainless steel check valves and premium seals — pre-installed from the factory for reliable sealing under continuous 3,700 PSI operation
• Mounting bolts and fasteners — hardware sized for direct-drive installation on compatible 1″ shaft gas or diesel engines
• Operator’s manual — complete installation, startup, operating, and maintenance procedures for the RKV4037VR35IDR including oil change intervals, chemical injector care, IDR system operation, and winterization protocol
• Parts schematic — exploded-view diagram with AR part numbers for every serviceable RKV4037VR35IDR component
• Factory test certification — every RKV4037VR35IDR load-tested at 50%, 100%, and 150% of rated output before leaving the AR manufacturing facility

RK Series Construction — Built for 3,700 PSI High-Output Continuous Duty

Solid Ceramic. Precision Brass. Bronze Connecting Rods. Oversized Crankshaft.

• Solid ceramic plungers provide excellent wear and heat resistance on the RKV4037VR35IDR, protecting seals and extending service intervals in high-temperature, high-duty 3,700 PSI environments. Individual replacement when service limits are reached.
• Bronze connecting rods and the oversized crankshaft on the RKV4037VR35IDR deliver the mechanical strength required for long hours of operation at full 3,700 PSI commercial load
• Precision-machined brass manifold resists corrosion and maintains accurate sealing surfaces on the RKV4037VR35IDR, ensuring consistent 3,700 PSI pressure performance over the pump’s service life
• Stainless steel check valves deliver reliable sealing and rapid pressure recovery under the high-frequency trigger cycling of professional commercial cleaning operations
• Triplex three-plunger design produces smooth, low-pulsation flow that reduces vibration and component fatigue on hoses, spray guns, and fittings throughout the wash system

Front-Access Serviceability and Maintenance

Protecting the RKV4037VR35IDR Investment Through Planned Maintenance

• Front-access piston packings and valve assemblies — packing and valve service on the RKV4037VR35IDR is accessible with standard tools from the front of the pump without full crankcase disassembly
• Oil sight glass and vented dipstick — at-a-glance oil level monitoring and simplified oil change procedures on the RKV4037VR35IDR without removing the pump from service
• Oil service on schedule — break-in oil change at 50 hours; full service every 500 hours or 3–5 months. Clean oil and correct level protect bearings and crankshaft integrity at 3,700 PSI continuous commercial duty.
• Chemical injector circuit flushing — flush the RKV4037VR35IDR injector circuit with clean water after every detergent session to prevent chemical residue buildup in the venturi passage
• Inlet supply must exceed 4.0 GPM — size inlet plumbing, filtration, and suction hose for the RKV4037VR35IDR’s 4.0 GPM demand to prevent cavitation at this pump’s elevated operating pressure
• Winterization is mandatory — protect the RKV4037VR35IDR with RV-grade environmentally safe antifreeze for storage and transport in cold conditions to prevent cracked manifolds and destroyed seals

Typical Applications

Where the RKV4037VR35IDR Delivers Best Results

• Fleet wash bays with high trigger-cycle frequency — buses, semi-trucks, delivery vans, and municipal vehicles where the RKV4037VR35IDR’s IDR eliminates trigger-release pressure spikes across hundreds of daily trigger cycles, reducing cumulative hose and fitting fatigue in production wash environments
• Construction equipment washdown — bulldozers, excavators, loaders, and skid steers where 14,800 CU output with chemical pre-treatment and instant pressure dump capability handles maximum contamination with improved operator control
• Agricultural machinery — tractors, sprayers, harvesters, and barn sanitation systems where on-demand detergent capability and IDR-protected trigger cycling support safe, efficient operation across varied agricultural cleaning tasks
• Industrial facilities — factory wash bays, machinery cleaning, and concrete surface preparation where the RKV4037VR35IDR’s three-function VR35 + injector + IDR assembly provides the most complete pressure control and safety specification available at this output
• Marine services — boats, docks, marina washdown, and portside maintenance where the RKV4037VR35IDR’s brass manifold corrosion resistance and IDR-protected trigger cycling support safe operation around water and changing crew
• Mobile contractor rigs with frequent idle cycling — trailer- and truck-mounted systems that cycle frequently between wash and idle modes where the RKV4037VR35IDR’s IDR instant dump minimizes both pressure spike stress and thermal buildup during high-frequency trigger-off events throughout all-day operation

For operators who prefer a fully configured direct-drive system rather than a bare pump assembly, WSHPWR also carries complete gas and diesel engine pump packages ready to mount on a frame or trailer.

5-Year US Warranty, Full Rebuildability, and Wholesale Pricing

High-Output RK Series Performance Backed by Domestic Support

The RKV4037VR35IDR is protected by Annovi Reverberi’s 5-year limited warranty through AR North America’s US-based warranty and service network. Warranty coverage is maintained by operating the RKV4037VR35IDR with the factory-installed components and following published installation and maintenance requirements. Every internal wear component — solid ceramic plungers, bronze connecting rods, brass manifold seals and o-rings, stainless check valve seats and springs, Gymatic VR35 unloader service parts (AR22287), IDR regulator service components, piston packing kits, and crankcase bearings — is stocked domestically through AR’s authorized distribution channels. Contractors, rental fleet operators, municipal purchasing departments, resellers, and volume buyers are invited to contact the WSHPWR wholesale team for pricing on the RKV4037VR35IDR and the complete Annovi Reverberi pump and unloader assembly line. WSHPWR maintains one of the most complete AR North America inventories available through any US web store — with thousands of AR products in stock and a continually expanding catalog.

14,800 Cleaning Units. 3,700 PSI. 4.0 GPM. VR35 + Injector + IDR Instant Dump. Factory-Matched.

Italian Engineering. Three-Function Control Assembly. Instant Pressure Safety. US Warranty Coverage.

For contractors, fleet operators, industrial maintenance professionals, and system builders who need 4.0 GPM at 3,700 PSI — with the most complete factory-matched pressure control assembly available: Gymatic VR35 bypass regulation, I-series integrated chemical injection, and IDR Instant Dump Regulator that eliminates trigger-release pressure spikes for safer operation and reduced component fatigue in high-cycle professional environments — the RKV4037VR35IDR delivers a factory-tested, fully documented, and completely rebuildable assembly from one of the global pressure pump industry’s most trusted manufacturers. Fourteen thousand eight hundred cleaning units. Direct drive. One-inch keyway shaft. VR35 bypass. Integrated injector. IDR instant dump. Front-access service design. Five years of US warranty. A decade of service life.

Volume buyers, resellers, and rental fleet operators can reach the WSHPWR wholesale team directly at wholesale@wshpwr.com to discuss pricing for quantity purchases across the complete Annovi Reverberi lineup — including pumps, unloader assemblies, and service parts.