RKV4G37DVR35IDR 4.0 GPM 3700 PSI Triplex Pump | VR35

RKV4G37DVR35IDR by Annovi Reverberi — RK Series Triplex Plunger Pump with Gymatic VR35 Unloader and Chemical Injector | 4.0 GPM | 3,700 PSI | 1″ Hollow Keyway Shaft | SAE J609A Gas and Diesel Engine Drive | Bronze Connecting Rods

The RKV4G37DVR35IDR by Annovi Reverberi is a professional-grade RK Series triplex ceramic plunger pump engineered for gas and diesel engine-driven industrial, fleet, contractor, and commercial pressure washing systems requiring high-volume output at 3,700 PSI with integrated downstream chemical application capability. Rated at 4.0 GPM and 3,700 PSI at 3,400 RPM, the RKV4G37DVR35IDR delivers 14,800 cleaning units — combining the high-volume coverage advantage of 4.0 GPM with 3,700 PSI pressure output that penetrates heavy contamination more aggressively than 3,000–3,200 PSI platforms while operating within the Gymatic VR35 unloader’s rated envelope with 300 PSI of comfortable headroom.

The RKV4G37DVR35IDR carries the Gymatic VR35 unloader — AR’s elevated-capacity Gymatic variant rated to 4,000 PSI and 5 GPM — providing 300 PSI of operating headroom above the 3,700 PSI output for stable, well-regulated bypass performance. The integrated downstream chemical injector delivers the complete two-mode professional wash platform — high-pressure rinse and low-pressure detergent pre-soak — through a single factory-configured RK Series assembly built around a reinforced aluminum crankcase with bronze connecting rods and front-access piston packing and valve serviceability.

Built by Annovi Reverberi in Modena, Italy — with US-based operations, a domestic parts distribution network, and dedicated AR North America technical support — the RKV4G37DVR35IDR 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 RKV4G37DVR35IDR is a long-term investment in a high-output RK Series commercial pump platform capable of a decade of productive service life.

Decoding the RKV4G37DVR35IDR Model Number

What Every Segment of This AR Pump Designation Tells You

The RKV4G37DVR35IDR encodes pump series, output, shaft type, unloader family, injector status, and a suffix element requiring confirmation:

• RKV — Pump series: RK Series triplex plunger pump — AR’s industrial pump platform built around a reinforced aluminum crankcase with front-access piston packing and valve serviceability for continuous industrial duty
• 4G37 — Performance rating: 4.0 GPM flow rate at 3,700 PSI maximum operating pressure — 14,800 cleaning units
• D — Shaft version: Direct Gas/Diesel Drive — 1″ hollow keyway crankshaft bore for direct coupling to gasoline or diesel engine 1″ output shafts via F24 SAE J609A face flange
• VR35 — Unloader system: Gymatic VR35 — AR’s elevated-capacity Gymatic unloader family rated to 4,000 PSI and 5 GPM. At 3,700 PSI the VR35 provides 300 PSI of operating headroom — stable, responsive bypass regulation well within the VR35’s 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
• DR — Suffix element: verify with AR North America before installation. This suffix may indicate a Dump Regulator component integrated into the unloader assembly providing managed pressure dump functionality — consistent with the IDR (Integrated Dump Regulator) designation used on other AR pump configurations in this series. Confirm the DR element’s role with AR North America to ensure correct system plumbing and operation.

RKV4G37DVR35IDR at 3,700 PSI — The High-Volume Mid-High Pressure Platform

The RKV4G37DVR35IDR‘s 3,700 PSI / 4.0 GPM output occupies a productive position in the AR commercial pump range:

• vs 4.0 GPM / 3,000 PSI (12,000 CU): The RKV4G37DVR35IDR delivers 23% more cleaning productivity through 700 PSI additional pressure at the same 4.0 GPM flow — same coverage speed, significantly more cutting power on heavy soils, caked contamination, and embedded grime
• vs 4.0 GPM / 4,000 PSI (16,000 CU): 300 PSI lower pressure with the same 4.0 GPM volume — broader engine compatibility and lower HP demand than the full 4,000 PSI duty point, while retaining the Gymatic VR35 unloader for accurate bypass regulation
• vs 3.5 GPM / 3,500 PSI (12,250 CU): The RKV4G37DVR35IDR delivers 21% more cleaning productivity through both higher flow and higher pressure simultaneously

For operators whose applications call for 3,000 PSI-plus cleaning force at high volume — fleet washing, heavy equipment, large concrete surfaces — the RKV4G37DVR35IDR’s 14,800 CU output delivers a meaningful step up from standard commercial pump configurations without requiring the highest-class engine HP of 4,000 PSI pumps.

Key Specifications

RKV4G37DVR35IDR 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 — 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 / 3,700 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, RK Series ‘D’ version, 1″ shaft, gas and diesel engine compatible (AR part AR41866)
• Unloader System: Gymatic VR35 — brass-body Gymatic unloader, adjustable pressure regulation, rated to 4,000 PSI and 5 GPM; 300 PSI operating headroom above 3,700 PSI output
• 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 RKV4G37DVR35IDR Assembly Ready for Installation

Every RKV4G37DVR35IDR 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 without modification
• 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 RKV4G37DVR35IDR 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 RKV4G37DVR35IDR component for field and shop reference
• Factory test certification — every RKV4G37DVR35IDR 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

Well Within Rated Envelope. Stable Bypass. Two-Mode Capability.

The Gymatic VR35 unloader on the RKV4G37DVR35IDR is rated to 4,000 PSI and 5 GPM — providing 300 PSI of operating headroom above the pump’s 3,700 PSI output:

• Stable regulation at 3,700 PSI — the VR35 operating 300 PSI below its 4,000 PSI rated ceiling produces confident, responsive bypass regulation behavior. The RKV4G37DVR35IDR’s VR35 operates in a comfortable zone within its design envelope, delivering consistent pressure output during continuous production wash cycles.
• Extended unloader service life — bypass valve components and seating surfaces operating with 300 PSI of headroom experience less cumulative stress than at maximum-rated pressure, extending the rebuild interval on the RKV4G37DVR35IDR in high-cycle commercial environments
• Adjustable then tamper-resistant — locked operating pressure maintained consistently across crew rotations and extended daily use without re-adjustment or drift
• Internal bypass operation — trigger-off bypass smoothly redirects the full 4.0 GPM flow at 3,700 PSI, 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 RKV4G37DVR35IDR operator switches to low-pressure application mode. No separate injector hardware required.
• Brass body construction — resists corrosion from cleaning chemicals, chlorinated water, and sustained industrial field exposure

Integrated Chemical Injection — Two-Mode Wash at 3,700 PSI / 4.0 GPM

Pre-Soak, Degrease, and 3,700 PSI Rinse Through the RKV4G37DVR35IDR

• Venturi-driven downstream injection — the VR35-integrated injector draws detergent or degreaser from a supply container when the RKV4G37DVR35IDR operator switches to low-pressure application mode. No chemical pump or powered dosing system required.
• Two-mode workflow at 4.0 GPM / 3,700 PSI — chemical pre-soak breaks down 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 rinses more surface area per minute than 3.0–3.5 GPM alternatives, reducing total wash cycle time on large-surface production jobs.
• No separate injector hardware required on the RKV4G37DVR35IDR — one assembly, two operating modes.
• Injector maintenance — flush the RKV4G37DVR35IDR 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 HD Construction — Built for High-Volume Continuous Duty

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

• Reinforced aluminum crankcase — aluminum’s high thermal conductivity dissipates friction-generated heat more effectively than iron or steel alternatives during continuous high-RPM operation on the RKV4G37DVR35IDR, maintaining lower operating temperatures at bearing and seal interfaces across extended duty cycles
• Bronze connecting rods resist the repeated load cycling of 4.0 GPM / 3,700 PSI operation at 3,400 RPM, extending connecting rod service life in commercial continuous-duty environments
• Solid ceramic plungers resist abrasion and thermal shock at 3,700 PSI across extended commercial operating hours. Individual replacement when service limits are reached — no full 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 overlapping pressure pulses that reduce pulsation-induced fatigue stress on hoses, spray guns, and fittings throughout the wash system connected to the RKV4G37DVR35IDR

Front-Access Serviceability — RK Series Maintenance Advantage

Packing and Valve Service Without Full Disassembly

• Front-access piston packings — packing replacement on the RKV4G37DVR35IDR 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 on the RKV4G37DVR35IDR is 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 RKV4G37DVR35IDR 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 for 4.0 GPM / 3,700 PSI loads. Verify engine horsepower against the RKV4G37DVR35IDR’s 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 RKV4G37DVR35IDR 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
• Compact installation envelope — direct coupling reduces skid and trailer frame dimensions for portable contractor rigs
• Included mounting hardware — bolts and fasteners sized for the F24 SAE J609A bolt pattern are supplied in the box

Typical Applications

Where the RKV4G37DVR35IDR Delivers Best Results

• Professional pressure washing contractors — two-mode wash workflow combining 3,700 PSI / 4.0 GPM rinse with VR35-integrated chemical pre-soak through the RKV4G37DVR35IDR for concrete cleaning, building exterior washing, surface preparation, and commercial property maintenance
• Heavy fleet and vehicle washing — trucks, trailers, buses, and heavy equipment where 4.0 GPM volume speed and 3,700 PSI cleaning force with chemical pre-treatment handle heavy contamination on large-surface fleet vehicles
• Industrial equipment washdown — construction machinery, process equipment, and industrial plant surfaces where the RKV4G37DVR35IDR’s 3,700 PSI penetrates contamination more aggressively than 3,000–3,200 PSI alternatives
• Concrete and hard surface cleaning — parking lots, sidewalks, loading docks, and warehouse floors where 14,800 CU output with integrated chemical pre-treatment provides efficient production cleaning results
• Agricultural operations — tractors, combines, sprayers, and barn facilities on gas or diesel engine-powered rigs where high-volume output and chemical pre-soak capability are both operational requirements
• Municipal and government services — utility vehicles, public works equipment, and infrastructure cleaning where the RKV4G37DVR35IDR’s diesel compatibility, high volume, and integrated chemical capability are all required
• Mobile contractor rigs — trailer and skid-mounted systems where the RKV4G37DVR35IDR’s compact RK Series direct-drive footprint and front-access serviceability support operational efficiency across diverse daily field jobs

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

High-Output RK Series Performance Backed by Domestic Support

The RKV4G37DVR35IDR 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 RKV4G37DVR35IDR — 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 RKV4G37DVR35IDR 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 RKV4G37DVR35IDR 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 RKV4G37DVR35IDR 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. RK Series. VR35 Bypass. Integrated Chemical Feed.

Italian Engineering. High-Volume Mid-High Pressure Platform. Front-Access Service. US Warranty Coverage.

For contractors, industrial operators, fleet managers, and municipal services who need 4.0 GPM high-volume output at 3,700 PSI — above standard commercial platforms and below maximum-pressure requirements — with the Gymatic VR35 unloader operating comfortably within its rated envelope, integrated downstream chemical injection, RK Series reinforced aluminum crankcase with front-access serviceability, and bronze connecting rods on a proven industrial pump platform, the RKV4G37DVR35IDR 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.