The FOX BTH-Plastic Series Flat Diaphragm – Bellows Pulsation Damper is an advanced engineering solution for the correct management of pulsations and pressure stabilisation within complex hydraulic systems. Designed to offer maximum efficiency, this component plays a decisive role in preserving circuit integrity and extending the service life of the installed pumps.

Operating Principle and Optimisation

The damping dynamics are based on a principle whereby the mechanical life of the device is inversely proportional to the increase in the internal compression ratio. For the accumulator to operate correctly as a pulsation damper, 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 close consideration the specific type of pump used and the operating temperature value of the fluid. Installation is extremely versatile: it can be carried out horizontally or vertically, provided that the nitrogen charging valve is strictly oriented upwards.

Construction Features and Material Range

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

To adapt to the different requirements of the fluids used and to thermal stress, the damper body can be selected in four distinct thermoplastic compounds:

  • The BTHP version in polypropylene (PP) is optimised for an operating range from 0°C to +70°C.

  • The BTHPVC model in unplasticised polyvinyl chloride (PVC-U) is guaranteed for temperatures from -5°C to +50°C.

  • The BTHPVCC version in chlorinated polyvinyl chloride (PVC-C) raises the upper limit, operating between -5°C and +60°C.

  • For the most demanding contexts, the BTHPVDF option in polyvinylidene fluoride (PVDF) offers a temperature range from -20°C to +80°C.

Special Versions and International Compliance

The modularity of the FOX BTH-Plastic Series Flat Diaphragm – Bellows Pulsation Damper allows the integration of connections with ANSI B16.5 or UNI/DIN flanges, as well as versions with integrated flanges or special fittings manufactured upon specific request. For maximum performance, a high-pressure version up to 15 bar and the completely maintenance-free BTHP-SMF model are available.

Finally, to ensure installation in every market, the product can be supplied on request with certifications compliant with the main 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 tests issued by bodies such as DNV/RINA, Lloyd’s/ABS and BV.

Summary Technical Table

Summary technical table of the main features