Nitrogen Charging Booster for Accumulators – Precharge Pressure & Procedure

Published 2026-10-17 · Jinan Shangling Technology Co., Ltd.

A hydraulic accumulator stores energy, absorbs shock and compensates for leakage in hydraulic systems. Bladder, piston and diaphragm accumulators all require a nitrogen precharge before operation and during routine maintenance. This article explains how to set the precharge pressure, what equipment to use, and the safe charging procedure.

1. How to Set the Accumulator Precharge Pressure

The nitrogen precharge pressure is a key design parameter. Common engineering practice:

1. Energy storage duty: precharge at 60%-70% of the minimum system working pressure;
2. Shock absorption duty: precharge at 60%-90% of the working pressure (depending on impact conditions);
3. Leakage compensation duty: precharge close to the minimum working pressure (about 90%).

Temperature correction is essential. According to Boyle's law, nitrogen pressure is proportional to temperature – roughly 3.5% per 10°C. Always re-check the pressure at the operating temperature.

2. Charging Equipment: Gas Booster Pump Solution

Accumulator precharge pressures typically range from 10 MPa to 35 MPa, while a standard nitrogen cylinder delivers only 13-15 MPa and its pressure drops as it empties. A gas booster pump (nitrogen booster) intensifies cylinder nitrogen to a stable high pressure, up to 100 MPa or more.

A typical charging skid consists of: nitrogen cylinder → filter → gas booster pump → high-pressure hose → accumulator charging valve, with a precision gauge or pressure transducer for auto stop and pressure-holding.

3. Charging Procedure

1. Ensure the accumulator is fully depressurized, then connect the charging valve to the booster outlet;
2. Pressurize slowly in stages (0.5 / 0.8 / 1.0 × target), checking seals at each stage;
3. At target pressure, close the charging valve and hold for 5-10 minutes – a stable gauge reading means success;
4. Disconnect and record pressure and temperature.

4. Common Problems

Rapid pressure drop after charging usually indicates a leaking charging valve or a damaged bladder; gauge drift with temperature is normal physics – convert to the standard temperature; never charge accumulators with oxygen or flammable gas.

5. Shangling Solution

Jinan Shangling Technology supplies nitrogen booster pumps and complete accumulator charging skids, 10-100 MPa output, with computer-controlled auto hold and custom designs based on accumulator volume, target pressure and site gas source. For more details, please call 18668913679 or email ljys@163.com.