PVD-2B-40P PVD-1B-28 PVD-00B-15 Nachi Pump 8-45cc 245Bar

Product Overview

The PVD-00B-15-3-4733A, PVD-2B-40P, and PVD-1B-28L3DPS-10G5-4281F belong to the Nachi PVD Series of variable split-flow axial piston pumps, purpose-built for 1–6 ton class mini excavators and compact construction equipment. The PVD Series features a split-flow architecture delivering two equal flow streams from a single pump body coaxial output, with flow deviation between circuits controlled to within 1% — fundamentally ensuring excavator straight-line travel stability. Constant horsepower control is integrated as standard equipment across the series, and the internal drain design eliminates the need for external drain piping, with an extremely short overall length for installation in confined engine compartments. Optional rear-mounted gear pumps (single or dual) can be integrated for auxiliary hydraulic circuit power.

Manufactured to original Nachi technical specifications with full drop-in interchangeability. The PVD-00B-15-3-4733A fits Takeuchi TB016 and other 1.5–2.5 ton mini excavators. The PVD-2B-40P-16G5 fits Hitachi ZX60-5G, Doosan35, PC40/ZX40/EX40 excavators. The PVD-1B-28L3DPS-10G5-4281F fits Kobelco SK30SR mini excavators. Every pump undergoes 100% simulated load testing at the factory, covering pressure hold, dual-circuit flow balance, and constant horsepower control valve dynamics.

Technical Specifications 

• Series: Nachi PVD Series

• Design: Variable split-flow axial piston pump, swashplate type, dual-circuit equal output

• Pump Size & Displacement (Full Series): PVD-00B (8×2 cc/rev) / PVD-0B (12×2 cc/rev) / PVD-1B (17×2 cc/rev) / PVD-2B (22.5×2 cc/rev) / PVD-3B (33×2 cc/rev)

• Maximum Working Pressure: 24.5 MPa (245 bar) — uniform across the series

• Maximum Speed: 2,800 rpm (PVD-00B/0B) / 2,700 rpm (PVD-1B) / 2,600 rpm (PVD-2B) / 2,400 rpm (PVD-3B)

• Rated Speed: 2,800 rpm (PVD-00B) / 2,600 rpm (PVD-0B) / 2,500 rpm (PVD-1B) / 2,400 rpm (PVD-2B) / 2,200 rpm (PVD-3B)

• Minimum Speed: 900 rpm

• Control Type: Constant horsepower control (standard); optional power shift (total horsepower control)

• Drain Type: Internal drain — no external drain piping required

• Mounting Flange: SAE standard flange (PVD-2B: SAE B 2-bolt)

• Port Configuration: PVD-2B partial configurations: 20+20+16+4.5 cc/rev multi-section split

• Applicable Excavator Class: ≤1.5 ton (PVD-00B) / 2.5 ton (PVD-0B) / 3.5 ton (PVD-1B) / 5.5 ton (PVD-2B) / 6.0 ton (PVD-3B)

• Optional Configurations: G—Gear pump / P—Power shift / B—Valve block

• Reference Weight: 9 kg (PVD-00B) / 13 kg (PVD-0B) / 15 kg (PVD-1B) / 20 kg (PVD-2B) / 27 kg (PVD-3B)

Model Code Interpretation (Examples):

• PVD-00B-15-3-4733A: PVD-00B pump body size (8×2 cc/rev), 15 as maximum total displacement code (~15 cc/rev per circuit), 3 as port/mounting variant code, 4733A as design number. Fits Takeuchi TB016 1.5-ton mini excavator.

• PVD-2B-40P-16G5: PVD-2B pump body size (22.5×2 cc/rev), 40P as maximum total displacement code (40 cc/rev) with P for right-hand rotation, 16G5 as gear pump configuration (16 cc/rev gear section), G5 as seal type and gear pump configuration code. Fits Hitachi ZX60-5G and Doosan35.

• PVD-1B-28L3DPS-10G5-4281F: PVD-1B pump body size (17×2 cc/rev), 28 as maximum total displacement code (28 cc/rev), L3 as left-hand rotation and port variant, DPS as control and interface specification, 10G5 as gear pump configuration (10 cc/rev), 4281F as design number and customization suffix. Fits Kobelco SK30SR.

Data based on Nachi PVD Series technical documentation. The PVD-00B minimum configuration actual displacement is 8×2 cc/rev, with maximum working pressure of 24.5 MPa uniform across the series. Some third-party sources cite different pressure ratings for PVD-1B-28L3DPS — verify against the original manual.

Key Technical Advantages

1. Dual-Circuit Equal Flow Design — Ensures Straight-Line Travel

The defining engineering feature of the PVD Series is its single-pump coaxial dual-circuit equal output architecture. Conventional solutions employ two separate pumps in series, where flow deviation between circuits is governed by manufacturing tolerances. The PVD Series delivers two identical flow streams from a single pump body, with port-to-port flow variation controlled to within 1% — fundamentally eliminating left-right travel motor flow imbalance and ensuring trajectory accuracy during straight-line excavator travel without operator correction. This design also simplifies hydraulic circuit routing and reduces potential leak points.

2. Constant Horsepower Control (Anti-Stall Technology) — Full Engine Power Utilization

The PVD Series integrates constant horsepower control as standard equipment, with optional gear pump feedback signal integration to keep pump drive power below the engine power curve. The control mechanism adjusts swashplate tilt angle based on the combined power output of both pump circuits. Even when only one circuit is under load, the constant horsepower control still maximizes engine power utilization, improving machine speed and productivity. The optional power shift (total horsepower control) mode further extends the pump’s power regulation range.

3. Internal Drain Structure and Compact Design

The PVD Series employs an internal drain structure, with case leakage returning to the reservoir through internal passages — no external drain lines required. This design reduces the number of external fittings and potential leak points while significantly shortening overall pump length for easy installation in space-constrained mini excavator engine compartments. The PVD-00B minimum pump body weighs approximately 9 kg, and the PVD-2B approximately 20 kg, offering clear power density advantages among comparable dual-circuit pumps.

4. Axial Piston Architecture and High-Efficiency, Low-Noise Operation

The PVD Series utilizes swashplate-type axial piston architecture, maintaining high efficiency (η ≥ 90%) across high-pressure operating regimes. Piston pairs are manufactured from high-strength alloy steel with precision-honed cylinder bores, sustaining stable volumetric efficiency at 24.5 MPa working pressure. Slippers, port plates, and support components adopt noise-reduction structures, with operating noise controlled to ≤75 dB, significantly improving operator working conditions. Optional rear-mounted gear pumps can be integrated on the back of the piston pump to power auxiliary hydraulic circuits.

Application Areas

• Mini Excavator Main Pump: 1–6 ton class mini excavator travel, swing, boom, arm, and bucket hydraulic drive

• Compatible OEM Machines: Takeuchi TB016 (PVD-00B-15-3-4733A); Kobelco SK30SR (PVD-1B-28L3DPS-10G5-4281F); Hitachi ZX60-5G, Doosan35, PC40/ZX40/EX40 (PVD-2B-40P-16G5)

• Compact Construction Machinery: Small loaders, skid steer loader hydraulic drive systems

• Municipal Engineering Machinery: Municipal maintenance equipment, micro-tunneling equipment auxiliary hydraulic systems

• Agricultural Machinery: Small tractor hydraulic hitch and steering systems

Expert Maintenance Tips

Pre-Installation Cleanliness Control: Before installing PVD Series pumps, verify hydraulic system cleanliness meets ISO 4406 18/16/13 or better. Port plugs should be removed and piping connected immediately after unboxing — environmental exposure should not exceed 15 minutes. Before first start, fill the pump case with clean hydraulic oil to the maximum allowable level. Dry-start is strictly prohibited. Since the PVD Series uses internal drain structure, no external drain line connection is required during installation, but adequate oil level in the pump case must be ensured.

Constant Horsepower Control Valve Calibration: The PVD Series constant horsepower control mechanism regulates the combined power output of both pump circuits. During calibration, monitor both outlet pressures with separate gauges and verify power matching under simultaneous dual-circuit loading conditions. The objective of constant horsepower control is to keep total pump drive power below the engine power curve to prevent engine stall. After control valve replacement or major overhaul, verify dual-circuit synchronization in accordance with Nachi factory test standards. The control valve on the PVD-00B minimum pump body is smaller — pay extra attention to adjustment screw travel limits.

Operating Oil Temperature Management: The PVD Series recommended operating oil temperature range is 15–60°C. When starting with oil temperature below 15°C, warm the hydraulic oil or run at low speed and low load until oil temperature reaches 15°C before applying full load. Prolonged operation above 60°C accelerates seal aging and fluid degradation — inspect the cooling system if oil temperature consistently exceeds this threshold. For the PVD-00B small displacement specification, oil temperature management is particularly important due to the smaller pump body heat dissipation surface area.

Oil Maintenance Schedule: Replace hydraulic oil and filter after the first 500 hours of operation. Thereafter, replace every 2,000 hours or 12 months, whichever comes first. Recommended viscosity grade: VG 32–46 mineral hydraulic oil, viscosity range 10–200 cSt. If the system is equipped with an online particle counter, replace oil and inspect filter differential pressure immediately when cleanliness drops to ISO 4406 20/18/15.

Long-Term Storage Protection: For pumps stored over 3 months, drain case oil, fill with rust-preventive oil, and plug all ports. Before recommissioning, flush with flushing oil for 30 minutes and confirm flushing oil cleanliness meets specification before connecting to the system. Always refill the case to the maximum allowable level before restart.