SEIM PX055 Screw Pump | Rolls-Royce Norwinch 635CT001-8

SEIM PX055#4BR0R2HBX18X0200 Screw Pump | Rolls-Royce Marine Norwinch 635CT001-8

The SEIM PX055#4BR0R2HBX18X0200 is a specialist positive-displacement triple-screw pump designed for severe marine machinery applications. This continuous flow unit, made in Italy by SEIM S.r.l, is designed for high viscosity lubricating oils, hydraulic fluids and mineral oils without flow pulsation or fluid shearing.

This particular design is the main power/lubrication unit pump for Rolls-Royce Marine Norwinch hydraulic deck machinery systems, specifically incorporated as part of the Norwinch 635CT001-8 platform. Inside a high-grade nodular cast iron casing is a nitrided steel triple-screw design that provides great volumetric efficiency, superb self-priming properties and ultra-low acoustic signatures under varying operational pressures.

Technical Specifications: SEIM PX055#4BR0R2HBX18X0200

Key Features

1. Pulsation-Free Fluid Dynamics: The precision-interlocking triple-screw geometry ensures uniform, continuous axial displacement, eliminating fluid pressure spikes and downstream line vibration.
2. High Volumetric Efficiency: Optimized tolerances between the nitrided steel rotors and the nodular cast iron chamber provide superior sealing, maintaining stable flow metrics even across wide thermal and viscosity swings.
3. Advanced Low-Acoustic Footprint: Specially profiled screw tracks drastically reduce cavitation thresholds and mechanical friction noise, complying with stringent marine engine room decibel constraints.
4. Robust Self-Priming Performance: The internal design establishes a rapid vacuum seal, allowing for fast air evacuation and fluid lift during system startups from dry conditions.
5. Resilience to Air Emulsification: Engineered to manage hydraulic fluids containing entrained air bubbles without losing prime or sustaining localized structural pitting.

Industrial Applications

• Deck Machinery Lubrication: Supplying continuous pressure-regulated lubrication oil to high-load gears inside Rolls-Royce Norwinch mooring and towing winches.
• Hydraulic Power Unit Feed: Serving as the charge or auxiliary circulating pump within marine low-pressure/medium-pressure hydraulic distribution loops.
• Marine Thruster & Gearbox Cooling: Circulating thermal-transfer and lubrication oils through auxiliary propulsion systems and reduction gear assemblies.
• Offshore Fluid Transfer: Transporting high-viscosity fuel, mineral, or synthetic oils from storage reservoirs to daily service tanks under varying ambient conditions.

The Engineer’s Inspection Protocol

When installing or replacing a triple-screw pump on a Norwinch HPU, shaft alignment is your single most critical failure point. A misalignment of even fractions of a millimeter will cause rapid wear on the mechanical seal, leading to premature leakage or catastrophic rotor binding.

1. Pre-Start Priming is Non-Negotiable. Never run this pump dry to “test rotation direction.” The internal screw tolerances rely strictly on the handled fluid for systemic lubrication and hydrodynamic balance. Always manually pre-fill the pump casing via the upper gauge port before initial power application.
2. Inspect the Mechanical Seal Drain Room. If replacing a unit that leaked, verify the state of the intermediate coupling flange drain hole. Blocked drain paths back up fluid into the motor bearings, causing an auxiliary electrical fault.
3. Suction Line Integrity. Ensure the suction line flange gaskets are perfectly seated. Because the PX055 has high self-priming suction power, a micro-fissure at the flange won’t necessarily leak oil outward; instead, it will pull atmospheric air inward, causing severe emulsification and phantom pressure drops down the line.

FAQs

What makes the SEIM PX055 architecture superior to gear pumps in marine environments?

Unlike conventional external or internal gear pumps, the triple-screw design moves fluid axially without squeezing actions or directional changes. This eliminates flow pulsation, radically reduces operating noise levels, and minimizes oil foaming or emulsification under high velocities.

Is the SEIM PX055#4BR0R2HBX18X0200 interchangeable with other industrial screw pumps?

No. While standard industrial PX series pumps share base sizing metrics, this configuration features a specialized shaft extension, specific Viton/SiC sealing profiles, and custom SAE flanged port layouts engineered exclusively to mate with Rolls-Royce Marine Norwinch machinery. Always verify the full suffix configuration before swapping units.

What viscometric boundaries must be maintained for optimal pump operation?

The unit performs optimally between 20 cSt and 400 cSt. However, it can reliably handle cold-start viscosities up to 5000 cSt at reduced rotational velocities, or thin down to 1.2 cSt for specialized low-viscosity fluids, provided adequate inlet head pressure prevents cavitation.