The FOX Special Series Bladder Accumulator with Flanged Connections is a large-scale hydropneumatic storage solution, ideal for integration into complex, high-capacity hydraulic systems. Designed to ensure maximum reliability in industrial environments, this device features an intelligent top-repairable design that significantly simplifies and speeds up inspection and maintenance operations, reducing system downtime.

Construction Features and Materials

The main structure of the HG series accumulators is manufactured using high-strength carbon steel. For marine, chemical, or highly corrosive environments, FOX offers the special HGX series, entirely made of AISI 304L or AISI 316L stainless steel. The accumulator body is typically supplied with an external coating applied according to the standard FOX procedure, while customized coatings are available upon request to meet specific project requirements.

The capacity range is among the widest on the market, with volumes starting from 100 liters up to an impressive 5000 liters, meeting the needs of extremely high-power hydraulic systems.

Operational Specifications

From a performance perspective, these devices are tested for operation with a maximum working pressure (PS) of up to 50 bar. The stringent test pressure (PT) applied during testing is calculated using coefficients of 1.43, 1.3, or 1.5 times the nominal working pressure, ensuring wide structural safety margins.

The permitted operating temperature range (TS) extends from -20°C to +80°C, enabling operation in countless industrial applications. Recommended installation is strictly vertical, ensuring the nitrogen valve is positioned upwards.

To maximize the mechanical life of the component — which is inversely proportional to the compression ratio increase — it is recommended to maintain a P2/P0 ratio of 2.5 and never exceed the technical limit of 4.

When the accumulator operates as a pulsation dampener within the hydraulic circuit, the nitrogen precharge pressure should be maintained between 60% and 80% of the working pressure, depending on the installed pump type and operating temperatures.

Bladder Variants and Fluid Compatibility

The operating core of the accumulator, namely the bladder, is supplied as standard in polyurethane. This polymer offers excellent chemical compatibility with the most common mineral oils, fuels, and non-aggressive hydraulic fluids.

To address specific pumping requirements involving chemically aggressive fluids or non-standard temperatures, FOX provides alternative bladder compounds such as IIR, NBR, FPM, and ECO.

The nitrogen precharge valve, located on the upper end, is available with standard 5/8″ UNF or M28x1.5 threading.

Flanged Connections and International Certifications

Safe connection to the hydraulic circuit is ensured through the use of high-sealing flanged connections. Available configurations include SAE 3000, SAE 6000, ANSI B16.5, or UNI/DIN flanges, ensuring global interoperability.

Customized connections can also be manufactured upon request. Reflecting its high quality and safety standards, the accumulator can be supplied with major international certifications including CE (2014/68/EU-PED), ATEX (2014/34/EU), ASME VIII Div.1/Div.2, KOSHA, SELO, DNV/RINA, and many other certifications for the global market.

Technical Summary Table