RKV4G37D-VR35ID 4.0 GPM 3600 PSI Triplex Pump | VR35

RKV4G37D-VR35ID by Annovi Reverberi — RK Series Triplex Plunger Pump with Gymatic VR35 Unloader and Chemical Injector | 4.0 GPM | 3,700 PSI | Bronze Connecting Rods | 1″ Hollow Keyway Shaft | SAE J609A Gas and Diesel Engine Drive

The RKV4G37D-VR35ID by Annovi Reverberi is a commercial and industrial RK Series triplex ceramic plunger pump engineered for gas and diesel engine-driven pressure washing systems requiring high-volume 4.0 GPM output at 3,600 PSI with integrated downstream chemical application capability. Rated at 4.0 GPM and 3,700 PSI at 3,400 RPM, the RKV4G37D-VR35ID delivers 14,800 cleaning units — combining the coverage speed of 4.0 GPM volume with 3,700 PSI pressure output that handles heavy contamination, grease, caked grime, and large commercial surface areas more aggressively than standard 3,000–3,200 PSI platforms. The Gymatic VR35 unloader provides 300 PSI of operating headroom above 3,700 PSI output — stable, confident bypass regulation well within the VR35’s 4,000 PSI rated envelope.

The RKV4G37D-VR35ID is built around the RK Series platform — AR’s industrial pump architecture with a reinforced aluminum crankcase for effective heat dissipation during continuous high-RPM operation and front-access piston packing and valve assemblies that simplify field maintenance without requiring full pump disassembly. Bronze connecting rods, solid ceramic plungers, and stainless steel valves complete the internal specification. The integrated downstream chemical injector delivers the complete two-mode wash platform — high-pressure rinse and low-pressure detergent pre-soak — through a single factory-configured assembly.

Built by Annovi Reverberi in Modena, Italy — with US-based operations, a domestic parts distribution network, and dedicated AR North America technical support — the RKV4G37D-VR35ID arrives as a complete, factory-tested assembly. Pre-filled with AR break-in oil, equipped with a Gymatic VR35 unloader 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 RKV4G37D-VR35ID is a long-term investment in a high-output RK Series commercial pump platform capable of a decade of productive service life.

Decoding the RKV4G37D-VR35ID Model Number

What Every Segment of This AR Pump Designation Tells You

The RKV4G37D-VR35ID encodes pump series, output, shaft type, unloader family, and configuration directly:

• RKV — Pump series: RK Series triplex plunger pump — AR’s industrial pump platform with reinforced aluminum crankcase and front-access serviceability
• 4G37 — Flow and pressure segment: 4.0 GPM at 3,700 PSI. This pump was originally rated at 3,700 PSI and has since been re-rated to 4,000 PSI by AR North America, making the RKV4G37D-VR35ID a capable replacement pump for both 3,700 PSI and 4,000 PSI system applications.
• D — Shaft version: Direct Gas/Diesel Drive — 1″ hollow keyway crankshaft bore for direct coupling to gasoline or diesel engine 1″ output shafts
• VR35 — Unloader system: Gymatic VR35 — AR’s elevated-capacity Gymatic internal bypass unloader rated to 4,000 PSI and 5 GPM. At 3,600 PSI the VR35 provides 400 PSI of operating headroom — stable, responsive bypass regulation comfortably within the rated envelope
• I — Chemical injector: Included — a downstream soap and chemical injector is integrated into the Gymatic VR35 unloader assembly, enabling low-pressure detergent application without a separate injector fitting
• D (trailing) — Variant designation: distinguishes this injector-equipped VR35 configuration within the RKV 3,600/3,700 PSI platform family

The RKV4G37 Platform — Three Variants at High Output

The RKV 4.0 GPM / high-pressure family includes three configurations sharing the same RK Series platform, F24 flange, 1″ keyway shaft, reinforced aluminum crankcase, and bronze connecting rods:

• RKV4G37DF24VR35 — Gymatic VR35, no injector, no IDR. Straight high-pressure water output for external chemical management. 3,700 PSI / 14,800 CU.
• RKV4G37D-VR35ID (this model) — Gymatic VR35, integrated chemical injector, “D” variant. Two-mode wash capability. Originally rated 3,700 PSI / 14,800 CU; re-rated to 4,000 PSI — serves as a capable replacement for both 3,700 and 4,000 PSI applications.
• RKV4G37DVR35IDR — Gymatic VR35, integrated injector, IDR suffix. Two-mode with IDR component. 3,700 PSI / 14,800 CU. Verify IDR role with AR North America.

Key Specifications

RKV4G37D-VR35ID Technical Details at a Glance

• Flow Rate: 4.0 GPM (gallons per minute)
• Maximum Pressure: 3,700 PSI (originally rated; re-rated to 4,000 PSI — suitable replacement for both 3,700 PSI and 4,000 PSI systems)
• Cleaning Units: 14,800 (GPM × PSI at 3,700 PSI)
• Operating Speed: 3,400 RPM
• Pump Type: RK Series triplex ceramic plunger pump — three-piston crankshaft-driven design for smooth, consistent high-pressure output
• Crankshaft Bore: 1″ hollow keyway — direct engagement with gas or diesel engine 1″ output shaft
• Crankcase: Reinforced aluminum — heat-dissipating architecture for thermal stability during continuous high-RPM operation
• Manifold Material: Forged brass — dense, pore-free construction for corrosion resistance and sustained high-pressure cycle integrity
• Plungers: Solid ceramic — exceptional hardness, wear resistance, and thermal shock resistance across extended commercial operating hours
• Connecting Rods: Bronze — premium fatigue strength and wear resistance at 4.0 GPM / 3,600 PSI continuous duty cycles
• Valves: Stainless steel — precise seating geometry, scale resistance, and reliable performance under continuous cycling
• Serviceability: Front-access piston packings and valve assemblies for simplified field maintenance
• Lubrication: Oil-bath crankcase lubrication with vented dipstick and sight glass
• Flange: F24 — SAE J609A direct-drive flange for RK Series ‘D’ version, 1″ shaft, gas and diesel engine compatible (AR part AR41866)
• Unloader System: Gymatic VR35 — brass-body internal bypass unloader, adjustable pressure regulation, rated to 4,000 PSI and 5 GPM; 300 PSI operating headroom above original 3,700 PSI rating; direct match at re-rated 4,000 PSI
• Chemical Injector: Included — downstream venturi injector integrated into Gymatic VR35 unloader assembly
• Warranty: 5-year limited warranty — US-based coverage through AR North America

What’s Included in the Box

A Complete, Factory-Configured RKV4G37D-VR35ID Assembly Ready for Installation

Every RKV4G37D-VR35ID ships fully assembled and field-ready:

• Factory-installed Gymatic VR35 unloader with active chemical injector — pre-mounted and calibrated for field-ready operation with integrated downstream injector ready for detergent supply line connection
• 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
• Mounting bolts and fasteners — hardware sized for F24 SAE J609A direct-drive flange installation on compatible 1″ shaft gas or diesel engines
• Operator’s manual — complete installation, startup, operating, and maintenance procedures for the RKV4G37D-VR35ID including oil change intervals, packing and valve service guidance, chemical injector care, and winterization protocol
• Parts schematic — exploded-view diagram with AR part numbers for every serviceable RKV4G37D-VR35ID component
• Factory test certification — every RKV4G37D-VR35ID load-tested at 50%, 100%, and 150% of rated output before leaving the AR manufacturing facility

The Gymatic VR35 at 3,700 PSI — 300 PSI Headroom with Integrated Chemical Feed

Originally 3,700 PSI. Re-Rated to 4,000 PSI. Serves Both Applications.

The Gymatic VR35 unloader on the RKV4G37D-VR35ID is rated to 4,000 PSI and 5 GPM — providing 300 PSI of operating headroom above the original 3,700 PSI rating, and matching precisely at the re-rated 4,000 PSI ceiling:

• Dual-duty capability — the VR35’s 4,000 PSI rating means the RKV4G37D-VR35ID functions as a direct replacement in both 3,700 PSI systems (where the VR35 operates with comfortable 300 PSI headroom) and 4,000 PSI systems (where the VR35 is rated precisely at operating pressure). This re-rated range makes the RKV4G37D-VR35ID one of the more flexible replacement specifications in the AR RK Series lineup.
• Stable regulation across the rated range — whether operating at 3,700 or 4,000 PSI, the VR35 on the RKV4G37D-VR35ID delivers consistent, adjustable bypass regulation behavior across continuous production wash cycles
• Adjustable then tamper-resistant — locked operating pressure maintained consistently across every operator, every shift, and every production wash cycle without re-adjustment or drift
• Smooth internal bypass at 4.0 GPM — trigger-off bypass smoothly redirects the full 4.0 GPM flow, preventing deadhead pressure spikes during idle intervals on production wash jobs
• Integrated downstream chemical injector — the venturi injector draws detergent, degreaser, or pre-soak solution from a supply container when the RKV4G37D-VR35ID operator switches to low-pressure application mode. No separate injector hardware required.
• Engine load reduction in bypass — reduced back-pressure lowers engine load and fuel consumption during trigger-off idle intervals on full-day wash operations

Integrated Chemical Injection — Two-Mode Wash at 3,600 PSI / 4.0 GPM

Pre-Soak, Degrease, and 3,600 PSI High-Volume Rinse

• Venturi-driven downstream injection — the VR35-integrated injector on the RKV4G37D-VR35ID draws detergent or degreaser from a supply container when the operator switches to low-pressure application mode. No powered dosing system required.
• Two-mode workflow at 4.0 GPM — chemical pre-soak breaks down grease, oil, and embedded contamination on fleet vehicles, construction equipment, and commercial surfaces; full 3,700 PSI / 4.0 GPM rinse at 14,800 cleaning units removes loosened material efficiently. The 4.0 GPM flow rate covers more surface area per minute than 3.0–3.5 GPM alternatives, reducing total wash cycle time on large commercial and industrial surfaces.
• No separate injector hardware required on the RKV4G37D-VR35ID — one assembly, two operating modes.
• Injector maintenance — flush the RKV4G37D-VR35ID injector circuit with clean water after every detergent session to preserve long-term venturi function as detailed in the included operator’s manual.

RK Series Construction — Built for High-Volume Continuous Commercial Duty

Reinforced Aluminum Crankcase. Bronze Connecting Rods. Front-Access Service.

• Reinforced aluminum crankcase — aluminum’s high thermal conductivity dissipates friction-generated heat more effectively during continuous high-RPM operation on the RKV4G37D-VR35ID, maintaining lower operating temperatures at bearing and seal interfaces across extended commercial duty cycles
• Bronze connecting rods provide the fatigue strength and bearing surface wear resistance required for 4.0 GPM / 3,600 PSI continuous operation at 3,400 RPM, extending connecting rod service life in high-cycle commercial environments compared to aluminum alternatives
• Solid ceramic plungers resist abrasion and thermal shock at 3,700 PSI across extended commercial operating hours with individual replacement when service limits are reached — no full RKV4G37D-VR35ID pump replacement required
• Stainless steel valves maintain precise seating geometry through high-cycle 3,700 PSI / 4.0 GPM operation, resisting calcium scale and pitting that cause pressure loss over time
• Triplex three-plunger design produces smooth, overlapping pressure pulses that reduce pulsation-induced fatigue stress on hoses, spray guns, and fittings throughout the wash system

Front-Access Serviceability — RK Series Maintenance Advantage

Packing and Valve Service Without Full Disassembly

• Front-access piston packings — packing replacement on the RKV4G37D-VR35ID is accessible from the front of the pump without requiring full crankcase disassembly, reducing time and labor for the most frequent seal maintenance event in high-cycle commercial operation
• Front-access valve assemblies — inlet and outlet valve inspection and replacement accessible without removing the pump from the engine mount in most installations, enabling valve service during scheduled maintenance windows
• Reduced maintenance downtime — shorter service windows translate directly into faster return to productive operation for contractor rigs and commercial wash operations running the RKV4G37D-VR35ID at high output daily

F24 SAE J609A — Direct Drive for Gas and Diesel Engines

• Gasoline engine compatibility — direct bolt-up to commercial gas engines with a 1″ cylindrical output shaft and SAE J609A bolt pattern. Verify engine horsepower against the RKV4G37D-VR35ID’s 4.0 GPM / 3,600 PSI duty point before installation.
• Diesel engine compatibility — equally compatible with standard diesel engines equipped with a 1″ crankshaft and SAE J609A bolt pattern for contractor rigs and industrial equipment
• Direct close-coupling — the RKV4G37D-VR35ID mounts face-to-face against the engine with the 1″ hollow keyway crankshaft bore engaging the engine shaft directly, eliminating belt guards, pulleys, and tensioning hardware
• Included mounting hardware — bolts and fasteners sized for the F24 SAE J609A bolt pattern are supplied in the box with the RKV4G37D-VR35ID

Typical Applications

Where the RKV4G37D-VR35ID Delivers Best Results

• Professional pressure washing contractors — two-mode wash workflow combining 3,600 PSI / 4.0 GPM rinse with VR35-integrated chemical pre-soak through the RKV4G37D-VR35ID for concrete cleaning, building exterior washing, surface preparation, and commercial property maintenance
• Industrial equipment cleaning — removing oil, grease, and heavy debris from construction machinery, manufacturing equipment, and industrial plant surfaces where 3,600 PSI penetrates contamination more aggressively than 3,000 PSI platforms with chemical pre-treatment through the integrated injector
• Fleet and vehicle washing — trucks, buses, trailers, and service vehicles where 4.0 GPM volume speed and 3,600 PSI cleaning force with chemical pre-soak handle heavy road film and grease on large fleet surfaces efficiently
• Concrete and hard surface cleaning — parking lots, warehouse floors, loading docks, and commercial pads where 14,400 CU high-volume output with integrated chemical application provides productive commercial cleaning results
• Agricultural operations — tractors, harvesters, implements, and barn sanitation on gas or diesel engine-powered rigs where high-volume output and chemical pre-soak capability are both required
• Commercial property maintenance — building exteriors, garages, work yards, and outdoor facility surfaces requiring high-volume high-pressure cleaning with detergent-assisted efficiency
• Mobile contractor rigs — trailer and skid-mounted systems where the RKV4G37D-VR35ID’s compact RK Series direct-drive footprint, front-access serviceability, and two-mode chemical capability support diverse daily field jobs

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

High-Output RK Series Performance Backed by Domestic Support

The RKV4G37D-VR35ID is protected by Annovi Reverberi’s 5-year limited warranty through AR North America’s US-based warranty and service network. Every internal wear component of the RKV4G37D-VR35ID — solid ceramic plungers, bronze connecting rods, forged brass manifold seals and o-rings, stainless valve seats and springs, Gymatic VR35 unloader service parts, piston packing kits, and crankcase bearings — is stocked domestically through AR’s authorized distribution channels.

With consistent maintenance — break-in oil change at 50 hours, scheduled oil changes every 500 hours or 3–5 months, regular valve and packing inspection using the front-access design, chemical injector circuit flushing with clean water after every detergent session, and proper winterization using RV-grade environmentally safe antifreeze — the RKV4G37D-VR35ID is engineered for 10 or more years of productive commercial service life. AR North America’s domestic parts depth ensures rebuild kits, plunger sets, packing kits, and Gymatic VR35 unloader service components for the RKV4G37D-VR35ID are typically available same-week.

Contractors, rental fleet operators, municipal purchasing departments, resellers, and volume buyers are invited to contact wholesale@wshpwr.com for wholesale and special pricing on the RKV4G37D-VR35ID 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 Original Rating. Re-Rated to 4,000 PSI. RK Series. VR35 Bypass. Integrated Chemical Feed.

Italian Engineering. High-Volume Platform. Front-Access Service. Serves 3,700 and 4,000 PSI Systems. US Warranty Coverage.

For contractors, industrial operators, fleet managers, and facility teams who need 4.0 GPM high-volume output — originally rated at 3,700 PSI and re-rated to 4,000 PSI, making the RKV4G37D-VR35ID a capable replacement for either pressure class — with the Gymatic VR35 operating confidently across the full rated range, integrated downstream chemical injection for two-mode wash capability, RK Series reinforced aluminum crankcase with front-access piston packing and valve serviceability, and bronze connecting rods — the RKV4G37D-VR35ID 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 with integrated injector. 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.