Denison P7 variable axial piston hydraulic pump

The P7 is a variable displacement, axial piston pump built around a rotating cylinder barrel containing pistons arranged parallel to the drive shaft. A tiltable swash plate (yoke) controls piston stroke length, which in turn determines the pump's output flow at a given shaft speed. Because the swash plate angle is adjustable — either manually, hydraulically, or electro-hydraulically — the P7 can vary its displacement from zero up to its rated maximum without changing pump speed, giving system designers a way to match flow output to actual load demand rather than running at a fixed rate all the time.

Key Specifications at a Glance

While exact figures vary by design revision and configuration code, published data for the standard P7 places it in roughly this range:

Maximum displacement: approximately 7.25 in³/rev (about 119 cm³/rev)

Maximum operating pressure: up to 5,000–6,000 psi, depending on series and duty cycle

Maximum shaft speed: around 3,000 rpm

Approximate weight: roughly 154 lbs (bare pump)

Mounting: SAE-C (2-bolt) or SAE-D (4-bolt) flange

Shaft options: SAE splined or keyed drive shafts

Rotation: available in clockwise or counterclockwise configurations

Control Options on the P7

Pressure Compensator Control

The most common control type. A compensator spool senses system pressure and automatically strokes the swash plate back toward zero displacement as pressure approaches a preset maximum — protecting the system from overpressure while letting the pump supply exactly the flow the load needs at lower pressures.

Load-Sensing Compensator

A refinement on the standard compensator that also references downstream load pressure (via a sensing line from the valve or actuator), allowing the pump to supply only as much pressure as the load actually requires at any moment, rather than running to a fixed maximum. This is a common efficiency upgrade on mobile equipment with multiple, simultaneously operating functions.

Hydraulic and Electro-Hydraulic Stroker Controls

These allow an external hydraulic or electrical signal — from a joystick, PLC, or proportional valve — to directly command swash plate angle, giving an operator or control system direct, proportional command over pump flow. This is typical in closed-loop hydrostatic transmissions.

Torque Limiter Control

Limits the maximum input torque the pump can demand from its prime mover (engine or electric motor) by automatically de-stroking as pressure rises, protecting smaller power units from stalling under combined high-pressure, high-flow conditions.

Rotary Servo Control

Used in precision closed-loop applications where an external servo signal needs fine, repeatable control over displacement — common in test rigs and process machinery requiring tight flow regulation.

Real-World Applications

The P7's balance of displacement, pressure rating, and control flexibility puts it to work across a wide range of industries:

Mobile construction equipment — excavators, cranes, and drill rigs that need variable flow to multiple simultaneous functions without excess fuel burn.

Marine propulsion and deck machinery — where closed-loop hydrostatic drives benefit from proportional stroker controls.

Mining and material handling — blast hole drills and shredding equipment that demand high pressure and torque-limited operation to protect drivetrains.

Industrial presses and injection molding machines — applications where a load-sensing or compensator control cuts standby energy losses significantly compared to fixed-displacement pumps running against a relief valve.

Power generation and pulp/paper processing — continuous-duty settings where the pump's rugged, hydrostatically balanced wear surfaces support long service intervals.

For more information on the P7 hydraulic pump, please visit https://www.baolilaihydraulic.com/product/.

Specifications

Selection Table

Q1: Is the Denison P7 the same as a Parker P7 pump?

A1: Yes, for practical purposes. Denison Hydraulics' product lines were folded into Parker Hannifin's Hydraulic Pump Division, so current P7 pumps are sold, documented, and supported under the Parker Denison brand, typically as part of the Gold Cup or World Cup series.

Q2: How do I know which control type my P7 has?

A2: The pump's part-number/model code (stamped on the nameplate) encodes the control type — compensator, load-sense, electro-hydraulic stroker, hydraulic stroker, rotary servo, or torque limiter — along with shaft style, rotation, and mounting. Decoding it against Denison/Parker's key sheet is the fastest way to confirm exactly what's installed.

Q3: What is the price and delivery time of the P7 hydraulic pump?

A3: The specific price and delivery time will be provided based on the specific model you provide.

Q4: How to purchase a P7 hydraulic pump?

A4: You can visit https://www.baolilaihydraulic.com/contact/ to contact us and purchase our products through various methods.