FAQ - Frequently Asked Questions

Q1: What is the main application of the A4VSO 125 size pump?

A:​ The A4VSO 125 is a heavy-duty industrial pump​ designed for high-pressure systems requiring flows up to ~225 L/min. It is commonly used in metal forming (presses), injection molding, large machine tools, and heavy lifting equipment​ where 350 bar continuous pressure and robust construction are required.

Q2: How does the DR pressure control work?

A:​ The DR control is a pressure compensator. Below the set pressure, the pump delivers maximum flow (125 cc). When system pressure reaches the set point (adjusted via a screw on the control cover), the swashplate automatically de-strokes to maintain constant pressure, delivering only the minimal flow needed to compensate for system leakage. This saves significant energy compared to a fixed pump with a relief valve.

Q3: What drive motor power is required for this pump?

A:​ At 1500 rpm and 350 bar, the theoretical mechanical input power is approximately 109 kW. It is strongly recommended to use a 110 kW (≈150 HP)​ electric motor or engine to provide a safe margin for starting torque and peak pressure (400 bar) demands.

Q4: Can I add a gear pump to the back of this unit?

A:​ No.​ The code N00​ explicitly indicates no through-drive capability. The shaft does not protrude from the rear housing. If you require a charge pump or auxiliary pump, you must select a version with a through-drive suffix (e.g., K01, K02, etc.).

Q5: What are the critical suction (inlet) conditions?

A:​ This is a large displacement pump and requires excellent inlet conditions. At 1500 rpm, the absolute inlet pressure should be ≥ 0.8 bar​ (approx. -0.2 bar gauge). If running at the maximum speed of 1800 rpm, a pressurized inlet (boost pump) is mandatory​ to prevent severe cavitation and damage.