Hartmann PVC 34/43 Atmospheric Inlet Axial Piston Pumps

Overview

The Hartmann PVC 34/43 series are atmospheric inlet, variable displacement axial piston pumps from Hartmann Controls, offered in two displacements: the PVC 34 at 3.4 in³/rev (56.0 cm³/rev) and the PVC 43 at 4.3 in³/rev (71.0 cm³/rev). The PVC 34 is rated for 4,000 psi (275 bar) continuous and 5,000 psi (345 bar) peak, while the PVC 43 is rated for 3,000 psi (205 bar) continuous and 4,000 psi (275 bar) peak. Hartmann designed the series for long and dependable service in both industrial and mobile applications, and states that its experience in matching axial piston pumps to fluid power applications dates back to 1964.

Seven Star LLC supplies the Hartmann PVC 34/43 pumps, controls and service kits to hydraulic system builders, oil and gas service contractors, steel and metals plants and marine operators in Oman and the GCC. From our base in Muscat we provide engineering support for model selection, replacement of installed units and start-up guidance.

Operating Principle

Like other swash plate pumps, the Hartmann PVC 34/43 uses pistons in a rotating cylinder block that reciprocate against an inclined swash plate; in general, the swash plate angle sets the stroke and therefore the flow per revolution. In the PVC design the angle is controlled by dual control pistons, a big and a small piston arrangement that eliminates springs, allowing lower minimum pressures and greater control flexibility. The swash plate is forged from 4150 steel in a completely balanced design that removes the tilting and cocking moments which cause hysteresis in other pumps.

All PVC controls have a stackable modular design and are fully interchangeable between the two displacement models, so a pump can be changed in the field from one control function to another. An externally adjustable neutral stop can be tuned to remove oscillation near neutral or set beyond neutral for hi-lo circuits, and an adjustable maximum stroke limit sets the upper flow.

Engineering Design of the Hartmann PVC 34/43

For the Hartmann PVC 34/43, Hartmann highlights several design features: short, lightweight pistons for operation at high speed or with low lubricity fluids; two mounting frame sizes in SAE B 2-bolt and SAE C 2- and 4-bolt flanges; six drive shaft sizes in SAE B (0.875 in), SAE B-B (1.00 in) and SAE C (1.250 in), keyed or splined; overdesigned large tapered roller bearings for side loading and long bearing life; a large diameter through shaft that allows high through-shaft torques; and a separate hardened steel port plate that gives better wear resistance than treated iron and also makes the pump field reversible. Side ported pumps with through-drive can be converted to tandem pumps by adding an adapter flange and coupling to the rear pad.

For first start-up, Hartmann lists a twelve-step procedure: flush the system, fill the case, check rotation against the label, purge air at idle, load the circuit gradually and set the relief valve 200 to 250 psi above the desired compensator setting. The Hartmann PVC 34/43 technical manual also sets the installation rules. PVC pumps run on standard petroleum-based hydraulic fluids, with special construction for water-based fluids or phosphate esters; the optimum viscosity is 32 cSt, with 14 to 540 cSt acceptable for continuous heavy duty. Inlet fluid temperature should not exceed 140 °F and discharge temperature 170 °F, inlet resistance should stay within 6 in Hg, case drain back pressure must be below 15 psi, and a check or sequence valve should hold an overall back pressure of 250 psi. All pumps use Viton shaft seals as standard.

Key Features

Key features of the Hartmann PVC 34/43 series:

• Two displacements of 56.0 and 71.0 cm³/rev in a common platform.
• Continuous pressure ratings of 275 bar (PVC 34) and 205 bar (PVC 43).
• Theoretical flow at 1,800 rpm of 100 l/min (PVC 34) and 127 l/min (PVC 43).
• Maximum speeds of 2,800 rpm (PVC 34) and 2,500 rpm (PVC 43) with high speed port end configurations at 1.0 bar abs inlet.
• Springless dual control pistons and a balanced forged steel swash plate.
• Modular stackable controls interchangeable across both models.
• Large tapered roller bearings and a large diameter through shaft for tandem builds.
• Hardened steel port plate for wear resistance and field reversibility.

Industrial Applications

With flows above 100 l/min and pressures up to 275 bar, the Hartmann PVC 34/43 pumps suit larger hydraulic power units: presses and metal forming lines, steel and aluminium plant hydraulics, marine deck machinery, drilling and workover equipment, cranes and material handling systems. In Oman and the GCC, typical users include fabrication yards and workshops in Sohar, Duqm and Muscat, offshore and marine service companies, and industrial plants running older hydraulic systems that need direct replacements for installed PVC pumps.

Seven Star LLC supplies the Hartmann PVC 34/43 series with controls and spares and can cross-check installed units by nameplate. Related pumps on this site include the HARTMAN PV320R-AV1-A1D/32002-40 high-pressure axial piston hydraulic pump and the Bosch Rexroth A10VSO axial piston variable pump, and for hydraulic motors see the KRACHT KM Series hydraulic gear motor.

Technical Specifications

The Hartmann PVC 34/43 data below is taken from the Hartmann PVC Series 34/43 brochure and technical information sheet:

How to Order

Send Seven Star LLC the pump nameplate or required displacement, mount, shaft, rotation, porting and control to quote the Hartmann PVC 34/43. The brochure and technical information sheet for the Hartmann PVC 34/43 can be downloaded from this page. Our Muscat team will confirm availability and support replacement and commissioning across Oman and the GCC.