The FOX High Pressure Series Bladder Accumulator – High Pressure represents a large-size hydropneumatic solution, specifically designed to facilitate maintenance operations thanks to its top-repairable configuration. The accumulator body is made of resistant carbon steel, capable of withstanding a maximum working pressure (PS) of up to 50 bar, and is supplied with external epoxy coating according to the standard FOX procedure, or customizable according to project specifications. For systems operating in particularly corrosive environments or requiring higher hygiene standards, the range also includes the HGX Series, entirely manufactured in AISI 304L or 316L stainless steel. This family of high-pressure accumulators is designed to handle extremely large volumes, with capacities reaching up to 5000 litres.

Fluid Specifications and Internal Bladders

The operating heart of the accumulator is its internal bladder. The standard version is made of polyurethane, an elastomer that ensures excellent chemical compatibility with mineral oils, fuels and non-aggressive fluids in general. The permitted operating temperature (TS) for this standard configuration ranges from a minimum of -20°C to a maximum of +80°C. In response to specific technical requirements, the accumulator can be equipped with alternative bladders made of special materials, including IIR, NBR, FPM and ECO, allowing adaptation to a wide range of industrial fluids.

Installation and Hydraulic Connections

The technical guidelines prescribe installation exclusively in a vertical position, with the nitrogen valve facing upwards. The accumulator is supplied as standard with a nitrogen valve with 5/8″ UNF or M28x1.5 connection. On the fluid side, connection to the hydraulic circuit is made via flanged connections, compatible with industrial standards SAE 3000, SAE 6000, ANSI B16.5 or UNI/DIN. The manufacturer also offers the possibility of producing special connections upon specific request.

Operating Principle, Precharge and Life Cycle

To preserve the structural integrity of the bladder and optimize system efficiency, the recommended compression ratio (P2/P0) is 2.5, while the absolute maximum limit must not exceed 4. The mechanical life of the component is inversely proportional to the increase in the compression ratio. When the accumulator is used as a pulsation damper, the nitrogen precharge pressure must be accurately calibrated within a range between 60% and 80% of the working pressure; this calculation must also strictly take into account the type of pump installed and the operating temperature values.

International Compliance and Certifications

The product ensures high regulatory flexibility. Upon specific request, the accumulator can be certified in compliance with the most stringent international directives, including CE (2014/68/EU-PED), ATEX (2014/34/EU), ASME VIII Div.1 or Div.2 (Latest Edition) and U-Stamp + NB. Approvals are also available for global and marine markets, such as EN 14359, EN 13445, PD5500 (UK), KOSHA (Korea), SELO (China), CU-TR 032/2013 (Russia), DOSH (Malaysia), NR-13 (Brazil), CRN (Canada) and approvals from classification bodies such as BV, DNV/RINA and Lloyd’s / ABS.

Technical Summary Table of Main Features