W4443WS — Bertolini WMG-W Series Piston Pump | 4400 PSI | 4.3 GPM | Socket QC Outlet | 1″ Hollow Shaft

The W4443WS is the socket-ready, plumbed version of Bertolini’s WMG-W Series — the industrial-grade triplex piston pump platform that takes everything built into the standard W4443 and adds a continuous-duty adjustable bypass regulator machined directly into the manifold. Engineered and manufactured by Idromeccanica Bertolini S.p.A. in Reggio Emilia, Italy — a company that has been building high-pressure pumps since 1918 — the W4443WS is designed for operators who demand a complete, ready-to-mount pressure system with industrial pedigree, not a price-point pump dressed up with after-market plumbing.

In independent lifecycle testing, the W4443WS platform has demonstrated service life up to five times longer than popular name brands manufactured outside Italy’s industrial pump region. That is not a marketing claim — it is the measurable result of forged brass manifold construction, bronze connecting rods, ceramic plungers, oversized bearings, and a manufacturing culture in Reggio Emilia that has been refining this exact product category for over a century.

What’s in the Box

• SAE J609-1″ Flange with 4-Bolt and Lock Washer Kit — Everything needed for a seamless, rattle-free installation directly to your engine. Grade hardware included — nothing to source separately.
• Fully Assembled W4443WS Pump — Complete with adjustable industrial bypass regulator, adjustable chemical injector, factory break-in oil, and vented dipstick — installed, pre-lubricated, and ready to mount.
• Adjustable Industrial Bypass Regulator — Manifold-Integrated — This is not an add-on unloader bolted to the outlet port. The bypass regulator on the W4443WS is machined as part of the manifold itself — a single forged brass assembly that handles both pump output and bypass regulation in one continuous-duty rated component. Adjustable from low pressure up to the full 4400 PSI operating maximum. Continuous duty cycle rated — it does not require cool-down intervals, does not degrade under sustained bypass operation, and does not introduce the failure points associated with bolt-on unloader assemblies.
• Adjustable Chemical / Soap Injector — Factory-installed adjustable downstream injector for on-demand detergent draw. Dial in your preferred soap ratio at the injector body. Compatible with standard pressure washer detergents, degreasers, and cleaning solutions.
• AL-QC3/8B — 3/8″ F x 3/8″ F Brass Quick-Connect Socket (Outlet) — Installed on the pump outlet port. Precision-machined solid brass construction. Tool-free connect and disconnect for fast hose and gun changes. Smooth internal bore maintains full system pressure with no flow restriction.
• Factory Break-In Oil — Crankcase pre-filled with SynPower Gear Oil 75W-90. After the break-in period (50–100 hours), replace with standard SAE 75W-90 — and never change it again. Lifetime oil for the life of the pump.
• Vented Dipstick — Must be manually installed prior to field testing. Critical for preventing crankcase vapor buildup and protecting seals during operation. Do not run the pump without it installed.

Why the W4443WS Outperforms Box-Store Competitors

The pressure washer pump market is crowded with products built to a price point — pumps manufactured outside Italy’s industrial pump region using cast manifolds, aluminum connecting rods, standard bearings, and generic packing seals. These pumps work. For a while. The W4443WS is engineered to a different standard entirely.

The manifold-integrated bypass regulator on the W4443WS is a continuous-duty component. Box-store pumps typically use bolt-on unloader valves with plastic or lightweight aluminum bodies that are rated for intermittent use — fine for homeowner applications where the trigger is pulled for ten minutes and the pump sits for a week. In contractor and fleet washing operations where the pump runs for hours and the bypass circuit carries load every time the gun closes, those components fail predictably. The W4443WS bypass regulator is machined brass, integrated into the manifold body, and rated for exactly this kind of sustained use.

The bronze connecting rods, ceramic plungers, and oversized crankshaft bearings compound this advantage. In lifecycle testing, the W4443WS platform has demonstrated up to five times the service life of popular name brands built outside the Reggio Emilia industrial region. Five times longer between packing replacements. Five times longer before bearing service. Five times the return on the initial investment — for operators who run their equipment hard and measure pump life in seasons, not weekends.

WM Series vs Standard Pump Architecture — The Seal Difference

The W4443WS uses a “V” front seal and “U” rear seal system — fabric-reinforced nitrile buna construction engineered for the larger 15mm plunger diameter of the WMG platform. The “V” geometry is self-energizing under pressure, tightening contact force as system pressure increases rather than relying solely on mechanical preload. This makes the seal more effective at high pressure, more tolerant of minor plunger surface variation, and more resistant to the gradual compression set that causes standard packing to begin weeping over time. The nitrile buna compound provides excellent resistance to detergents, degreasers, and chemical cleaning solutions — making the W4443WS well suited for operations involving frequent chemical application.

Performance

What’s Inside the W4443WS

• Forged Brass Manifold — Increased Wall Thickness — Engineered for continuous-duty operation and maximum rigidity under overpressure events. The bypass regulator is machined into this same forged body.
• LowStressthread™ Valve Caps — Recessed O-ring design. Thread never contacts pressurized water. No Loctite required. Torque reduced by 40%.
• AISI 316 Stainless Steel Valve Assemblies — Mirror-finish, rapid-action check valves for corrosion resistance and maximum fluid dynamic efficiency.
• “V” Front Seal / “U” Rear Seal — Fabric-reinforced nitrile buna. Self-energizing under pressure. Excellent chemical and detergent resistance. Long service life under continuous-duty cycling.
• Solid Ceramic Plungers — High-grade ceramic for years of uninterrupted high-pressure performance with minimal seal wear.
• Bronze Connecting Rods (One-Piece) — Superior anti-friction performance, lower operating temperatures, and extended service life vs aluminum rods.
• Oversized Crankshaft Bearings — Extended service life under heavy and continuous-duty conditions.
• Forged Steel Crankshaft — Extended Length — Maximum structural rigidity for solid pump-to-engine coupling in any configuration.
• Die-Cast Aluminum Crankcase — Anti-corrosion alloy with diamond-tool machined plunger guide surfaces and enhanced cooling fins.
• Ventilated Oil Dipstick — Reduces risk of crankcase leakage due to vapor buildup. Must be installed prior to first run.

Specifications

Applications

• Professional contractor pressure washing — continuous-duty operation
• Fleet and heavy equipment washing programs
• Self-service car wash bay systems
• Honda GX and compatible engine direct-drive installations
• Industrial and commercial washdown systems
• Multi-shift operations requiring sustained bypass capability
• Chemical-intensive cleaning environments

7-Year Warranty

The W4443WS is backed by Bertolini’s industry-leading 7-year warranty — the direct result of over 100 years of pump engineering in Reggio Emilia, Italy. For operators who measure equipment by seasons of service rather than weekends of use, the W4443WS is built to earn that warranty and then keep running.