High-pressure hydraulic accumulators, piston cylinders, bladder units, safety valve blocks, and turn-key fluid power systems manufactured to ASME, CE/PED, and ISO standards.
SCHWERLL manufactures a series of standard piston accumulators in strict compliance with the certification requirements for special‑purpose equipment in major countries and regions worldwide. These accumulators are designed to withstand pressures of up to 200 MPa, with individual units offering nominal volumes of up to 1,500 L. They are suitable for applications involving high‑frequency transfer functions at frequencies of 200 Hz and above, with piston speeds reaching a maximum of 9 m/s. SCHWERLL’s piston accumulators are engineered for a wide range of demanding operating conditions and media, and the company provides specialized solutions tailored to fluids such as water‑glycol, phosphate ester, and mineral hydraulic oils.
Schwerll standard piston accumulators are suitable for the vast majority of industrial applications, compatible with mineral hydraulic oils, water‑emulsions, water‑glycol fluids, phosphate esters, and other media. The products comply with the special‑equipment regulations and standards of the country or region in target installation jurisdictions. Individual piston accumulators offer capacities up to 1,500 L, with design pressures reaching as high as 207 MPa, and piston speeds of up to 5 m/s. SCHWERLL piston accumulators can be equipped with a variety of proven gas‑charged fluid‑level monitoring systems.
The SCHWERLL standard bladder accumulator series uses high-grade synthetic elastomer compounds and a special process to produce bladders with low permeability, high fatigue life, wide-range thermal endurance (-40°C to +120°C), and special material adaptability for special media.
In industries such as low-pressure water treatment (16 bar and below), the Xiwel low-pressure, large-capacity bladder accumulator can be selected, with capacities up to 5,000 L. The internal bladder of this cushioning accumulator provides isolation, delivering excellent resistance to fouling and making it suitable for use with water and other corrosive liquid media.
Sivir supplies high‑performance bladder accumulators for the industrial sector, with design pressures up to 690 bar and capacities of up to 300 L. The outer diameter range includes 299, 325, 351, 356, and 426 mm, and the interface sizes are tailored to meet high‑flow operating requirements.
Compared with rubber diaphragms and metal pistons used as internal gas–liquid separation elements in accumulators, metal bellows offer superior gas tightness. For pressurized nitrogen service, their intrinsic nitrogen permeability is virtually zero. Leveraging this property, high-pressure metal‑bellows accumulators are well suited for applications where replenishing nitrogen is challenging, such as subsea ROV systems, underwater unmanned vehicles, hydraulic control systems within spacecraft cabins, and ultra‑compact vibration‑damping accumulators in vehicles.
On mobile devices, aircraft, and marine vessels such as speedboats, there are stringent weight‑reduction requirements for accumulators. Sevier employs electron‑beam welding technology to manufacture lightweight piston accumulators that comply with pressure vessel codes, thereby meeting the diverse industrial applications that demand reduced weight.
Imported leather and professionally manufactured diaphragms are used. The diaphragm shape and structure are designed using simulation to ensure reasonable compression and expansion characteristics. The diaphragm is made of all-natural rubber to ensure the best rubber properties. The diaphragm uses the most widely used adhesive integral molding process to ensure stable compression and oil discharge deformation characteristics, and high oil discharge stability. The diaphragm uses a special rubber adhesive to ensure the use characteristics after bonding. Diaphragm bags all strictly pass NF ISO 37 and other standard tests. A variety of rubber materials ensure more media adaptability. Low inherent permeability of rubber.
In medium- and low-pressure applications, oil–gas mixing tanks are used to control electro‑hydraulic servo systems, with water and air as the working fluids. Air is pressurized by an air compressor system. To ensure the reliability of the oil–gas mixing tank’s control, proper volumetric matching calculations must be performed, and a liquid‑level monitoring system should be installed.
Schwerll Company provides a stable and reliable piston displacement monitoring system for piston accumulators and their associated systems. Through displacement sensors installed on the gas side and externally, the system monitors the liquid level within the piston accumulator and calculates flow rate. This allows for monitoring of the gas energy within the piston accumulator or system, ensuring the accumulator’s operating status. Energy monitoring is especially crucial when the accumulator serves as a necessary power source for the system.
Severin threaded‑connection diaphragm accumulators are suitable for higher compression ratios—exceeding 4:1 and reaching up to 8:1—feature a serviceable design, and can be supplied in special materials such as stainless steel.
Sever’s welded‑structure diaphragm accumulators are available in two types: hot‑die forged construction and head‑welded construction.
