Hydraulic accumulators – low-maintenance and system-efficient downsizing.

Screwed or welded diaphragm accumulators or hydro/diaphragm accumulators are predestined for a variety of mobile applications, pulsation damping, process technology and for use in compact clamping aggregates. These pressure compensators use the compressibility of a gas (e.g. nitrogen) for storing energy. It consists of a liquid part, a gas part and a diaphragm as a leak-proof separating element, the material of which must be adapted to the respective application. With the pressure increase, the diaphragm accumulator is filled and the gas is compressed. By a pressure drop, the gas volume expands and the stored pressure fluid is returned to the hydraulic circuit. Diaphragm accumulators are generally inexpensive and suitable for small installation spaces. In addition, they are lightweight and maintenance-free. In addition, they offer a high degree of flexibility, especially with regard to the installation position.

• nominal volume: 0.075 to 4.0 l
• Temperature ranges: from -50 °C to +120 °C
• Maximum operating pressure P max: up to 750 bar
• Design: screwed or welded, various accumulator materials and diaphragm materials

Bladder accumulators are pressure accumulators that store liquids and thus energy via a flexible bladder and transfer these back to the hydraulic system when the system pressure drops. The bladder acts as a separator between the pressure fluid and the gas side. Because of the high extraction speeds and the absence of pressure differences, bladder accumulators are recommended as energy storage devices or emergency shut-offs in hydropower plants. These hydraulic accumulators also have the advantages of a simple design and the resulting serviceability, a long service life due to recurring tests and high pressure volumes of up to 450 l.  

• Nominal volume: up to 450 l
• Temperature ranges: from -50 °C to +120 °C
• Maximum operating pressure P max: up to 1000 bar
• Design: various accumulator body materials and elastomer materials

Piston accumulators isolate the gas and liquid spaces using a freely movable piston. A special sealing system, adapted to the respective application and the operating medium, is used for sealing. The primary applications for these accumulators are hydraulic applications with special media and large accumulator volumes. Because of the high-quality stainless steel housings and sealing systems used, piston accumulators are also used in seawater-resistant or seawater-protected applications. Other advantages are the flexible installation position and the wide range of possible adjustments. 

• nominal volume: 0.1 to 3,300 l
• Temperature ranges: from -60 °C to +200 °C
• Maximum operating pressure P max: up to 1,200 bar
• Design: screwed or welded, cylinder tubes made of high-quality pressure vessel steel, low-temperature steel or stainless steel

Pulsation dampers use the reflection principle and reduce harmful pressure peaks, pressure fluctuations or inadmissible temperature increases in positive displacement pumps. This prevents pressure pulsations and resonances from being transmitted to the entire hydraulic system. Irregularities in the volume flow are thus significantly reduced. The pulsation damper is usually mounted directly onto the pressure connection of the hydraulic pump. The pulsation dampers are also available in a robust stainless steel or polypropylene version and are suitable for corrosive operating conditions as well as low pressure systems up to 10 bar.  

• nominal volume: 0.05 to 50 l
• Temperature ranges: from -50 °C to +120 °C
• Maximum operating pressure P max: up to 1000 bar
• Design: screwed or welded, in various housing versions

Hydraulic accumulators are especially recommended for applications in which large oil quantities or volume flows are required for a short time only. Motor power and pump size can therefore be reduced accordingly, resulting in savings in valuable energy and system costs.

Make sure that the pressure vessel complies with all necessary pressure equipment guidelines, specific national regulations and transport regulations. Important decision criteria for the selection include the maximum operating pressure, preload pressure, nominal volume as well as the required medium compatibility and maintenance frequency. Servomotors with fixed displacement pumps can be a suitable alternative to hydraulic accumulators in special circumstances, because they also feed high volume flows into the system at short notice.

We are happy to advise you.