PVD-0B-19L3PS Nachi PVD Series Excavator Pump 24.5MPa

Product Overview

The PVD-0B-19L3PS-8G-4609F, PVD-1B-32, PVD-1B-30, PVD-2B-36, and PVD-2B-40 are core models within the Nachi PVD series of swashplate-type variable displacement dual axial piston pumps. The PVD series is specifically engineered as the main hydraulic pump for 1–6 ton class mini excavators, featuring a unique “Split-Flow” design that integrates two independent piston pump sections within a single housing, delivering two equal flows from the same drive shaft to ensure synchronous supply to the left and right travel motors — guaranteeing straight-line travel of the crawler undercarriage without operator correction.

The entire PVD series comes standard with Constant Horsepower Control, automatically reducing pump displacement as system pressure rises to maintain pump input power within the engine’s available power range, fully utilizing engine horsepower to increase machine speed and output power. The series features an internal drain structure, eliminating the need for external drain piping and adapting to compact engine compartments.

The PVD series is the original equipment manufacturer (OEM) hydraulic pump supplier for Hitachi, Kubota, JCB, Takeuchi, Caterpillar, Yanmar, and other leading mini excavator manufacturers, with extensive interchangeability in the global construction machinery aftermarket.

Model Code Breakdown (for procurement and engineering reference):

Using PVD-0B-19L3PS-8G-4609F as example:

• PVD: Nachi split-flow dual axial piston pump series

• 0B: Frame size code, suitable for ≤2.5 t excavators

• 19: Maximum total displacement code

• L3PS: Control and port configuration code

• 8G: Port and mounting configuration code

• 4609F: Factory calibration and batch identifier

Using PVD-1B-32 as example:

• PVD-1B: PVD series 1B frame, suitable for ≤3.5 t excavators

• 32: Maximum total displacement 32 cm³/rev (main pump 16+16 cm³/rev dual-section configuration)

Using PVD-2B-36 / PVD-2B-40 as example:

• PVD-2B: PVD series 2B frame, suitable for ≤5.5 t excavators

• 36 / 40: Maximum total displacement of 36 cm³/rev and 40 cm³/rev respectively (dual equal-section configuration)

OEM Cross-Reference (for procurement reference):

• PVD-0B-19L3PS-8G-4609F: Compatible with Volvo EC18C/EC20/EC20B/EC20C/EC25, Pel Job EB282/EB300

• PVD-1B-32: Compatible with Hitachi ZX30/ZX30U/ZX33U, Yanmar B37/B37-2, CAT 302.5C

• PVD-2B-36/40: Compatible with Hitachi EX35/EX40-2/EX45-2/EX55UR, JCB 8030/8035ZTS

Drop-in Replacement Advantage: Manufactured to exact Nachi OEM specifications, these pumps achieve complete drop-in interchangeability with the original PVD series for SAE B two-bolt mounting flange, 13T splined shaft (centering 101.6 mm), SAE standard port layout, and constant horsepower control module interface. Every pump undergoes 100% simulated load testing prior to shipment, validating 24.5 MPa pressure loading, constant horsepower control response, and volumetric efficiency under conditions replicating real-world duty cycles.

Technical Specifications 

PVD-0B Series General Specifications:

• Series: Nachi PVD Series (Swashplate-Type Dual Variable Axial Piston Pump)

• Frame Size: 0B

• Displacement per Section: 12 cm³/rev

• Total Displacement (Dual): 24 cm³/rev (12×2)

• Rated Continuous Working Pressure: 21 MPa (3045 psi)

• Maximum Intermittent Peak Pressure: 24.5 MPa (3553 psi)

• Maximum Allowable Speed: 2800 rpm

• Rated Operating Speed: 2600 rpm

• Minimum Speed: 900 rpm

• Control Type: Constant Horsepower Control (standard)

• Mounting Flange: SAE B two-bolt flange

• Shaft: 13T, centering 101.6 mm

• Drain Type: Internal drain structure (standard)

• Suitable Excavator Tonnage: ≤2.5 t

• Weight: Approx. 13 kg (base pump body)

Model PVD-0B-19L3PS-8G-4609F Configuration:

• Model Code: PVD-0B-19L3PS-8G-4609F

• Control Type: Constant Horsepower Control (standard)

• Port Configuration: 8G code configuration

• Factory Calibration: 4609F batch

PVD-1B Series General Specifications:

• Series: Nachi PVD Series (Swashplate-Type Dual Variable Axial Piston Pump)

• Frame Size: 1B

• Displacement per Section: 16 cm³/rev (max. 17 cm³/rev)

• Total Displacement (Dual): 32 cm³/rev (16×2)

• Maximum Intermittent Peak Pressure: 24.5 MPa (245 bar)

• Maximum Allowable Speed: 2700 rpm

• Rated Operating Speed: 2500 rpm

• Minimum Speed: 900 rpm

• Control Type: Constant Horsepower Control (standard)

• Mounting Flange: SAE B two-bolt flange

• Shaft: 13T, centering 101.6 mm

• Weight: Approx. 15 kg

Model PVD-1B-32 Configuration:

• Model Code: PVD-1B-32

• Total Displacement: 32 cm³/rev (16+16 cm³/rev)

• Control Type: Constant Horsepower Control (standard)

• Rotation: Right-hand (P code) or left-hand (L code)

• Port Configuration: Per G5/G8 code specification

Model PVD-1B-30 Configuration:

• Model Code: PVD-1B-30

• Total Displacement: 30 cm³/rev (15+15 cm³/rev)

• Control Type: Constant Horsepower Control (standard)

• Rotation: Right-hand (P code) or left-hand (L code)

PVD-2B Series General Specifications:

• Series: Nachi PVD Series (Swashplate-Type Dual Variable Axial Piston Pump)

• Frame Size: 2B

• Displacement per Section: 18 cm³/rev (max. 22.5 cm³/rev)

• Total Displacement (Dual): 36 cm³/rev (PVD-2B-36) or 40 cm³/rev (PVD-2B-40)

• Rated Continuous Working Pressure: 21 MPa (3045 psi)

• Maximum Intermittent Peak Pressure: 24.5 MPa (245 bar)

• Maximum Allowable Speed: 2600 rpm

• Rated Operating Speed: 2400 rpm

• Minimum Speed: 900 rpm

• Control Type: Constant Horsepower Control (standard)

• Mounting Flange: SAE B two-bolt flange

• Shaft: 13T, centering 101.6 mm

• Weight: Approx. 20 kg

Model PVD-2B-36 Configuration:

• Model Code: PVD-2B-36

• Total Displacement: 36 cm³/rev (18+18 cm³/rev)

• Control Type: Constant Horsepower Control (standard)

• Rotation: Right-hand (P code) or left-hand (L code)

Model PVD-2B-40 Configuration:

• Model Code: PVD-2B-40

• Total Displacement: 40 cm³/rev (20+20 cm³/rev)

• Control Type: Constant Horsepower Control (standard)

• Rotation: Right-hand (P code) or left-hand (L code)

PVD Series Displacement Size Reference:

• PVD-00B: 8×2 = 16 cm³/rev, 2800 rpm, ≤1.5 t, weight approx. 9 kg

• PVD-0B: 12×2 = 24 cm³/rev, 2800 rpm, ≤2.5 t, weight approx. 13 kg

• PVD-1B: 17×2 = 34 cm³/rev, 2700 rpm, ≤3.5 t, weight approx. 15 kg

• PVD-2B: 22.5×2 = 45 cm³/rev, 2600 rpm, ≤5.5 t, weight approx. 20 kg

• PVD-3B: 33×2 = 66 cm³/rev, 2400 rpm, ≤6.0 t, weight approx. 27 kg

Note: The entire PVD series has a maximum intermittent peak pressure of 24.5 MPa (3553 psi), with constant horsepower control as standard equipment.

Key Technical Advantages

1. Dual Equal-Flow Split Design with Straight-Line Travel Precision
The PVD series’ core technical feature is its “Split-Flow” design — integrating two independent piston pump sections within a single pump housing, delivering two equal flows from the same drive shaft. The flow deviation between the two circuits is ≤2%, ensuring synchronous supply to the left and right travel motors for straight-line travel of the crawler undercarriage without operator correction. This design fundamentally eliminates the travel deviation problem caused by flow imbalance in conventional dual-pump systems, significantly reducing operator fatigue.

2. Constant Horsepower Control with Full Engine Power Utilization
The PVD series comes standard with Constant Horsepower Control. As system pressure rises, the controller automatically reduces pump displacement to maintain pump input power (P×Q) within the engine’s available power range, fully utilizing engine horsepower to increase machine speed and output power. This control method effectively prevents engine stall under heavy digging loads while optimizing fuel efficiency. Optional Power Shift control provides dual power curve switching for light-load and heavy-load operating conditions.

3. Internal Drain Structure with Compact Installation Design
The PVD series features an internal drain structure as standard, where case drain oil returns directly to the suction side through internal passages without requiring external drain piping. This design significantly simplifies hydraulic system piping layout, adapting to the compact engine compartments of mini excavators. The PVD-0B base pump body weighs only approximately 13 kg, with compact dimensions, and the standardized SAE B two-bolt flange and 13T splined shaft interface require no adaptation for replacement.

4. High Power Density with Precision Swashplate Bearing System
The PVD series employs precision swashplate support structures across all frames from 00B to 3B. Pistons and cylinder bores are precision match-ground to micron-level clearances, maintaining stable volumetric and mechanical efficiency at 24.5 MPa peak pressure. The swashplate variable mechanism features short response times, with control spool and servo piston area ratios and spring rates precisely matched to ensure fast and stable displacement adjustment.

5. Integrated Auxiliary Gear Pump Options
The PVD series offers optional integrated high-pressure auxiliary gear pumps and pilot control gear pumps. High-pressure auxiliary gear pumps supply oil to auxiliary circuits, while pilot control gear pumps provide pilot oil sources for the machine’s valve blocks. This modular design provides flexibility for mini excavator hydraulic system integration, reducing the number of independent pumps and piping connection points.

6. Wide Hydraulic Fluid Compatibility with Broad Temperature Adaptability
The PVD series is compatible with ISO VG32 or VG46 anti-wear hydraulic oils, with a viscosity range of 15–400 mm²/s, meeting the requirements of construction machinery applications under different climate conditions. The housing is precision-cast from high-strength cast iron, with the material’s damping characteristics effectively suppressing structural vibration and fluid-borne noise. The seal material is NBR (nitrile rubber), with standard configuration suitable for mineral oil-based hydraulic fluids.

Application Areas

• Mini Excavators: Main hydraulic pump for 1–6 ton class mini excavators (the core application area for the PVD series)

• PVD-0B Compatible Models: Volvo EC18C/EC20/EC20B/EC20C/EC25, Pel Job EB282/EB300

• PVD-1B Compatible Models: Hitachi ZX30/ZX30U/ZX33U, Yanmar B37/B37-2, CAT 302.5C

• PVD-2B Compatible Models: Hitachi EX35/EX40-2/EX45-2/EX55UR, JCB 8030/8035ZTS

• Compact Construction Equipment: Small loader and small bulldozer hydraulic systems

• Municipal Maintenance Equipment: Small street sweepers, municipal maintenance machinery hydraulic drives

• Agricultural Machinery: Small agricultural excavators, orchard management machinery hydraulic systems

Expert Maintenance Tips

1. Pre-Start Pump Housing Priming (Mandatory)
Before starting the engine, manually pre-fill the main pump casing with clean, fresh hydraulic fluid through its highest case drain port. Operating an axial piston pump bone-dry — even for a few seconds — will score the valve plate and piston slippers, causing immediate total pressure loss.

2. Air Bleeding & Initial Startup Procedure
After installation, loosen the air bleed port on top of the pump housing. Crank the engine with the fuel supply disabled until clear, bubble-free oil flows from the port, then retighten. Allow the machine to idle under no load for 10 to 15 minutes to purge any trapped air from the hydraulic loop.

3. System Fluid Decontamination
If replacing a pump that suffered internal mechanical failure, completely drain and clean the hydraulic oil reservoir, flush all circuit lines, and clean the oil cooler. Replace all return and suction filter elements before starting the engine. System fluid cleanliness for the PVD series must meet ISO 4406 18/15 or better.

4. Relief Pressure Check
Verify system pressure relief valve settings upon startup. Incorrect pressure relief settings can lead to sluggish hydraulic controls, circuit overheating, or engine stalling under heavy digging load. The system relief pressure for the PVD series should be set below the 24.5 MPa peak pressure.

5. Constant Horsepower Controller Setting and Adjustment
The power control curve start point of the constant horsepower controller should be calibrated according to the engine’s power characteristics. During commissioning, set the power control start point with the pump at neutral (zero displacement). The power control setting must ensure that the system does not exceed the engine’s available power at maximum working pressure, preventing engine stall under heavy load conditions.

6. Hydraulic Fluid Replacement Interval
Replace hydraulic fluid every 1,000–3,000 operating hours or every 6 months, whichever comes first. Recommended fluids are ISO VG32 or VG46 anti-wear hydraulic oils. When changing hydraulic fluid, simultaneously replace filter elements and flush the system to ensure no residual contaminants remain. Monitor oil temperature during operation, ensuring it does not exceed 80°C.