Ultra-high-pressure pumps form the heart of high-performance hydraulic systems when large forces are required precisely and in a controlled manner. In demolition works, tunnel construction and rock excavation, as well as in natural stone extraction, they deliver the required pressure to reliably operate tools such as hydraulic rock and concrete splitters, concrete demolition shears, hydraulic shears, or steel shears. As part of a hydraulic power pack from Darda GmbH, they convert drive power into hydraulic pressure energy and thus provide the basis for controlled splitting, cutting, and pressing in concrete demolition, during building gutting, or in special demolition. These Darda hydraulic power units ensure a consistent pressure supply for the matched tools.
Definition: What is meant by an ultra-high-pressure pump
An ultra-high-pressure pump is a hydraulic pump that generates operating pressures significantly above the standard industrial hydraulics level, typically in the range of several hundred bar up to about 700 bar and more. It delivers a flow rate at high pressure with which cylinders, shears, and cutters develop their force. In hydraulic power packs from Darda GmbH, an ultra-high-pressure pump supplies, among other things, hydraulic wedge splitters, concrete demolition shears, as well as other attachments. Crucial is the interplay of pressure (determines force) and flow rate (determines speed): only this enables both powerful splitting and fast work cycles.
Function and design of an ultra-high-pressure pump
Ultra-high-pressure pumps operate on the positive displacement principle. Mechanical drive power (e.g., electric motor or combustion engine) drives a pump element that draws hydraulic fluid from a tank and delivers it into the working circuit at high pressure. According to Pascal’s law, the pressure is transmitted through the fluid with almost no loss and generates a correspondingly high force at the actuator (e.g., splitter cylinder, shear cylinder).
- Drive: Electric, combustion engine, or pneumatic; sized according to required power (pressure × flow rate).
- Pump element: Usually axial piston, radial piston, or multi-stage displacement pumps for high pressures.
- Oil tank and conditioning: Tank, strainer, filter, oil–air separator to minimize cavitation and wear.
- Valves and protection: Pressure relief valve, check valves, load-holding valves, pressure gauge for monitoring.
- Control block: Directional, proportional, or manual valves for single- and double-acting consumers.
- Lines and couplings: High-pressure hydraulic hose lines with suitable quick couplings and burst protection.
Physical fundamentals: force, pressure, speed
The force delivered at the tool is given by F = p × A (pressure × piston area). The flow rate Q determines the stroke or closing speed. For concrete demolition shears, a two-stage supply is often advantageous: high flow rate at low pressure for rapid approach, then high pressure at moderate flow rate for the actual separation. Hydraulic wedge splitters for rock and concrete benefit from very stable ultra-high pressure to ensure crack initiation and uniform splitting progress.
Pump types in the ultra-high-pressure range
Depending on the operating environment and required performance, different designs are used. Selection and sizing significantly influence force development, working speed, and energy efficiency.
- Axial piston pumps: High efficiency, compact design, suitable for continuous operation at high pressures.
- Radial piston pumps: Very pressure-resistant, smooth running with finely metered flow, proven at constant ultra-high pressure.
- Multi-stage displacement pumps: Switch from high flow at low load to high pressure at low delivery; useful for shear and cutter cycles.
- Hand and foot pumps: For special demolition with limited space or without external power supply; limited flow, but high pressure possible.
- Pneumatic-hydraulic intensifiers: Use compressed air as the drive and deliver high hydraulic pressures in ATEX zone or well-ventilated areas.
Applications in demolition, extraction, and special deconstruction
The ultra-high-pressure pump supplies hydraulic tools in different scenarios and must be matched to the respective task. In practice, the power pack, pump, valves, and hose assemblies are coordinated so that the required force, cycle time, and mobility are achieved.
- Concrete demolition and special demolition: Concrete demolition shears and hydraulic shears require fast approach speeds and high final pressures to separate reinforcement and concrete in a controlled manner.
- Building gutting and cutting: Multi cutters, steel shears, and tank cutters benefit from precise pressure regulation and sensitive hydraulic control to cut components in a targeted manner.
- Rock excavation and tunnel construction: Hydraulic wedge splitters and splitter cylinders require stable, low-vibration ultra-high pressure for low-noise, low vibration levels work. Further practical guidance is provided under rock demolition and tunnel construction.
- Natural stone extraction: Constant pressure holding and clean oil quality support repeatable splitting operations with varying rock structures.
- Special demolition: Mobile, compact power packs with ultra-high-pressure pumps enable work in confined, sensitive, or hard-to-reach areas.
Relation to concrete demolition shears and hydraulic wedge splitters
With concrete demolition shears, the focus is on a dynamic pressure–flow profile: fast jaw travel to contact, then powerful separation under ultra-high pressure. Hydraulic wedge splitters, on the other hand, operate with constant high pressure holding so that cracks define and propagate. Both tool types therefore impose different requirements on the pump and on the valve strategy of Darda GmbH’s hydraulic power pack.
Selection criteria for the appropriate ultra-high-pressure pump
The right pump results from the tool, the task, and the environment. In addition to pressure and flow rate, the power supply, operating duration, and ambient conditions influence the specification.
- Operating pressure and force demand: What final pressure is required, e.g., to cut reinforcement with a concrete demolition shear or to load a splitter cylinder?
- Flow rate and cycle time: What cycle speed is required (fast approach vs. powerful final stroke)?
- Power supply: Mains power, battery, or combustion engine—depending on mobility, emissions, and availability.
- Hydraulic circuit: Single- or double-acting consumers; need for fine metering or proportional control.
- Hydraulic fluid management: Viscosity, temperature window, filter fineness; design against cavitation with long hydraulic hose lines.
- Environment: Dust, moisture, temperature, noise control; special protective measures if necessary.
- Compatibility: Quick couplings, hose lengths, pressure ranges matched to hydraulic wedge splitters, concrete demolition shears, steel shears, tank cutters.
- Economics: Energy efficiency, service life, maintenance access, interchangeability of wear parts.
Safety, guidelines, and best practice
Ultra-high-pressure systems require special attentiveness. Professional design and regular inspections support safe operation. Safety information is always to be understood generally and does not replace an individual assessment of the specific use case.
- Overpressure protection: Set the pressure relief valve correctly; perform regular functional checks.
- Lines: Inspect high-pressure hydraulic hose lines for chafing, kink zones, and aging; use burst protection.
- Couplings: Keep clean, lock correctly; release pressure before disconnecting.
- Control: Emergency stop and depressurized start conditions; controlled pressure release at the end of work.
- Reference values and standards: Observe general principles of hydraulic operational safety (e.g., design and operating requirements for hydraulic systems).
Maintenance, oil care, and service life
Oil cleanliness and temperature management are decisive for the service life of an ultra-high-pressure pump. Particle wear and cavitation can be minimized through appropriate filtration, correct oil level, and proper operation.
- Oil condition: Viscosity appropriate to the operating temperature, avoid water and air ingress; change oil according to manufacturer specifications.
- Filtration: Size fine filters appropriately; monitor differential pressure and replace elements on schedule.
- Seals and bearings: Watch for leakage, temperature damage, and noise development.
- Pressure gauge and sensors: Regular calibration and functional checks support reproducible results when splitting and cutting.
- Hose and coupling service: Adhere to visual inspection and replacement intervals, especially for mobile operations on construction sites.
Typical failure modes and diagnostic notes
If pressure fails to build, causes can include an open pressure relief valve, contaminated filters, or air ingress. Slow cycles indicate insufficient flow (e.g., cavitation, clogged suction line). Unusual noises or overheating point to incorrect viscosity or insufficient lubrication. Diagnostics should begin systematically: visual inspection, pressure and temperature measurements, then step-by-step narrowing down of the assembly.
Hydraulic power packs and system integration
In practice, the ultra-high-pressure pump is linked in Darda GmbH’s hydraulic power pack with control blocks, cooling, and power supply to form a functional unit. The integration determines how precisely tools such as concrete demolition shears, splitter cylinders, hydraulic shears, multi cutters, steel shears, or tank cutters can be operated.
- Single- and multi-circuit systems: Parallel consumers require coordinated flow rates and priorities.
- Fine metering: Proportional valves enable slow approach, exact positioning, and controlled separation.
- Pressure-holding function: Load-holding valves prevent unintended yielding under load, for example when holding a concrete demolition shear.
- Mobility: Compact, robust power packs for confined construction sites; hose management for safe routing over longer distances.
Mobile vs. stationary
Mobile power packs facilitate special demolition and work in existing structures (building gutting), while stationary solutions in natural stone extraction or during tunnel heading excel through continuous operation and stable oil temperatures. The choice depends on cycle requirements, energy availability, and space conditions.
Sustainability and energy efficiency
Efficient ultra-high-pressure pumps reduce waste heat and energy demand. Demand-oriented control (e.g., automatic switching between high delivery volume and ultra-high pressure) shortens cycles, lowers idle losses, and supports quiet operation. In sensitive environments, the use of suitable hydraulic fluids can be helpful, provided they are compatible with seals and operating temperatures. Especially for low vibration levels splitting of rock or concrete, an efficient pressure supply contributes to reproducible results and predictable cycle times.