The Flat Diaphragm Pulsation Dampener – FOX BTH-Plastic Bellows Series represents an advanced engineering solution for the effective management of pulsations and pressure stabilization within complex hydraulic systems. Designed to deliver maximum efficiency, this component plays a crucial role in preserving circuit integrity and extending the service life of installed pumps.

Operating Principle and Optimization

The damping dynamics are based on a principle whereby the mechanical lifespan of the device is inversely proportional to the increase in the internal compression ratio. In order for the accumulator to operate correctly as a pulsation dampener, the nitrogen pre-charge pressure must be accurately set between 60% and 80% of the actual working pressure. This pre-charge must always take into careful consideration both the specific pump type used and the operating temperature of the fluid. Installation is extremely versatile and can be carried out either horizontally or vertically, provided that the nitrogen charging valve is strictly oriented upward.

Construction Features and Material Range

The separation element of the BTH-Plastic series, available as either a diaphragm or bellows, is entirely manufactured from PTFE (Teflon), a material ensuring excellent chemical compatibility and high mechanical flexibility. The system is tested for a maximum working pressure (PS) of 10 bar, with a test pressure (PT) equal to PS x 1.43 / 1.5. The device is supplied as standard with a nitrogen valve featuring a 5/8″ UNF connection.

To meet different fluid compatibility requirements and thermal stresses, the dampener body is available in four different thermoplastic compounds:

  • BTHP polypropylene (PP) version optimized for an operating range from 0°C to +70°C.
  • BTHPVC unplasticized polyvinyl chloride (PVC-U) model guaranteed for temperatures from -5°C to +50°C.
  • BTHPVCC chlorinated polyvinyl chloride (PVC-C) version extending the upper operating limit to +60°C, with a range from -5°C to +60°C.
  • BTHPVDF polyvinylidene fluoride (PVDF) option designed for the most demanding applications, offering a temperature range from -20°C to +80°C.

Special Versions and International Compliance

The modular design of the FOX BTH-Plastic Flat Diaphragm Pulsation Dampener allows the integration of ANSI B16.5 or UNI/DIN flange connections, as well as integrated flange versions and custom-made special fittings upon request. For maximum performance requirements, high-pressure versions (up to 15 bar) and the completely maintenance-free BTHP-SMF model are also available.

To ensure installation compatibility across international markets, the product can be supplied upon request with certifications complying with major global standards, including European CE (2014/68/EU-PED), British PD5500, Australian AS1210/4343, as well as specific approvals for KOSHA, SELO, DOSH, NR-13, ARH, and inspections issued by certification bodies such as DNV/RINA, Lloyd’s/ABS, and BV.

Technical Summary Table

Technical summary table of the main characteristics.