Casappa PLP Series Gear Pump Replacement | PLP20.14

The PLP, PLP10, PLP20, and PLP30 series (encompassing specific high-pressure industrial engineering ordering numbers such as PLP20.14D0-82E2-LGE/GD-N-EL) manufactured by LIC Hydraulic are high-efficiency, external geometric fluid spur gear pumps. They are engineered to deliver premium fluid power capacity for high-speed, high-pressure utility applications across both industrial hydraulics and mobile utility machinery. Adhering to European standard 4-bolt / SAE standard diamond mounting configurations, standard 1:8 tapered drive shafts with specialized woodruff keys, hydrostatically balanced floating side thrust plates, and unified European diamond flange fluid ports, this complete product platform provides 100% drop-in interchangeability with original Casappa (Polaris Series) classic PLP series hydraulic gear pumps.

In rugged agricultural vehicle operations, aerial utility lifts, and industrial power packs, the hydraulic gear pump experiences transient system overpressure spikes, continuous high-frequency fluid shear, and elevated operating oil temperatures. Standard light-duty aftermarket gear pumps often suffer from dynamic flexing of the center housing, which expands internal clearances, causes a severe drop in volumetric tracking, and leads to front shaft seal failure from internal case backpressure. LIC addresses these typical engineering weak points by utilizing a high-tensile extruded aluminum alloy matrix body paired with specialized three-dimensional hydrostatically balanced floating side plates. Every single gear pump module undergoes 100% full-load factory verification testing—including deep pressure relief stalling, maximum speed run-in, and volumetric internal slippage auditing before packaging. This guarantees that the unit delivers reliable mechanical efficiency and extended service life under continuous working pressures up to 250 bar.

Technical Specifications

Accurate, catalog-verified technical parameters in compliance with official Casappa Polaris PLP series external gear pump reference criteria:

• Product Series: PLP Platform High-Pressure External-Meshing Hydraulic Gear Pump Family (PLP10, PLP20, PLP30 Frames)

• Model Number Specification Code Breakdown (PLP20.14D0-82E2-LGE/GD-N-EL):

  • PLP20: Polaris Series Size 20 medium frame module, featuring an extruded high-strength aluminum body with heavy cast-iron mounting and rear covers.

  • .14: Sizing code displacement index, establishing a geometric位移 displacement of 14.4 cm³/rev (0.87 in³/rev).

  • D0: Rotational orientation and internal check valve layout, designating a clockwise (Right-Hand) rotation with internal low-pressure drainage check routing.

  • 82E2: Drive shaft and mounting flange geometry index, defining a standard European 4-bolt pattern (Ø36.5 mm pilot) paired with a 1:8 tapered high-tensile shaft including a standard woodruff slot.

  • LGE/GD: Integrated fluid port mapping code, indicating standard European diamond 4-hole flange threads (Oversized inlet port paired with a velocity-optimized outlet port).

  • -N: Standard Nitrile (NBR) elastomer seal configuration (Rated for continuous petroleum-base fluid operations from $-25^{\circ}C$ to $+80^{\circ}C$).

  • -EL: Engineering modification suffix, designating a specialized low-noise tooth profile configuration or custom integrated valve options built into the rear cover.

• Total Matrix Displacement Coverage Framework:

  • PLP10 Frame: 1.07 cm³/rev to 11.23 cm³/rev

  • PLP20 Frame (e.g., Core PLP20.14): 4.95 cm³/rev to 31.59 cm³/rev (where .14 stabilizes at 14.4 cm³/rev)

  • PLP30 Frame: 26.7 cm³/rev to 91.1 cm³/rev

• Standardized Pressure Threshold Ratings (PLP20.14 Specification):

  • Continuous Working Pressure (P1): 250 bar (25 MPa / 3625 psi)

  • Intermittent Peak Pressure Limit (P2): 280 bar (28 MPa / 4060 psi)

  • Transient Maximum Spike Pressure (P3): 300 bar (30 MPa / 4350 psi)

• Allowable Operational Rotational Velocity Range: Maximum speed up to 3500 rpm; Minimum stable self-priming speed down to 600 rpm.

• Net Individual Mass Weight: PLP20.14 base configuration approx. 3.8 kg (8.38 lbs).

Key Technical Advantages

• Hydrostatically Balanced Floating Thrust Plates: The internal assembly utilizes floating side thrust plates cast from a premium bronze alloy. The rear surfaces of these plates feature sealing channels energized by the pressure differential between the inlet and outlet ports. As operating loads rise, this pressure presses the plates firmly against the gear faces, keeping internal clearances tight and maintaining a volumetric efficiency above 95% at 250 bar.

• Extruded Aluminum Matrix Body with Cast-Iron Covers: The central pump body is extruded from high-density, heat-treated aerospace-grade aluminum alloy, while the front mounting and rear covers are cast from robust ductile iron. This composite design reduces overall pump mass by 40% compared to all-iron variants while providing the structural rigidity needed to prevent housing distortion under cyclic pressure loading.

• Low-Noise 12-Tooth Involute Gear Profile: The matching drive gears are machined from high-strength alloy steel with a refined 12-tooth involute profile and precision-chamfered tooth tips. This configuration minimizes fluid trapping and volume fluctuations during gear engagement, lowering fluid-borne noise by 4 to 6 dB(A) compared to traditional 8-tooth or 10-tooth pumps when operating at 3000 rpm.

• High-Pressure Dual-Lip Front Shaft Seal System: The front bearing housing incorporates a dual-lip high-pressure shaft seal assembly backed by internal check valve channels that route internal fluid leakage straight to the low-pressure suction side. This design allows the front shaft seal to reliably handle a continuous internal case pressure of up to 3.5 bar, helping prevent seal blowout from external return backpressure fluctuations.

Application Areas

The compact footprint, high power density, and fast self-priming capabilities of the PLP10, PLP20.14, and PLP30 series gear pumps make them suitable for primary and auxiliary fluid circuits across various industries:

• Mobile Construction Equipment & Municipal Utility Vehicles: Auxiliary pilot control loops for compact excavators, priority steering circuits for small wheel loaders, and tailgate lift/compactor cylinders for refuse trucks.

• Modern Agricultural Machinery & Forestry Implements: Three-point rear hitch lift systems for utility tractors, auxiliary header roller drives for combine harvesters, and primary log-splitter circuits.

• Industrial Hydraulic Power Units (HPUs) & Machine Tools: Lightweight hydraulic power packs, workholding fixture clamp tables for CNC machinery, and hydraulic lift platform stations.

• Truck-Mounted Cranes & Aerial Work Platforms: Outrigger stabilizer control manifolds and boom lift/extension cylinder arrays.

Expert Maintenance Tips

• Verify Woodruff Key Alignment and Locknut Torque on Tapered Drive Shafts: The primary PLP20.14D0-82E2-LGE/GD-N-EL model features a standard European 1:8 tapered shaft (code 82E2). When mounting pulleys, gears, or flexible couplings, ensure the woodruff key sits completely level inside its slot and does not protrude unevenly. Always use a calibrated torque wrench to tighten the front shaft locking nut (the recommended torque for standard M12 tapered shaft nuts is $50-55 N\cdot m$) to prevent micro-slippage that can shear the woodruff key and score the tapered mating surface.

• Pre-Fill the Pump Housing Through the Suction Port Prior to Initial Startup: Because the clearances between the bronze thrust plates and gear faces are exceptionally tight, the internal components are shipped with only a thin film of rust-preventative oil. After completing the plumbing installation and before starting the drive motor, fill the pump cavity with clean ISO VG 46/68 anti-wear hydraulic oil through the suction port and rotate the input shaft 3 to 5 times by hand. Starting the pump dry can cause immediate frictional heating that can score the bronze thrust plates, causing a permanent reduction in volumetric efficiency.

• Maintain Rigid Seals on the Suction Plumbing to Prevent Cavitation: The PLP20 aluminum pump operates at speeds up to 3500 rpm, which creates high fluid velocities at the suction side. Any minor air leak at the suction fittings, or restriction from a clogged inlet filter, will draw micro-bubbles into the pump gear cavities and cause cavitation. The rapid implosion of these bubbles can erode the internal aluminum surfaces, leading to rapid fluid contamination and generation of harmful metallic debris.