Operating supplies are the functional foundation of hydraulic demolition and cutting technology. From concrete demolition and special deconstruction to strip-out and cutting, all the way to rock excavation, tunnel construction, natural stone extraction, and special operations, the correct selection and care of hydraulic oils, lubricating greases, as well as cleaning and protective agents determine performance, precision, and durability. Especially for concrete demolition shears and stone and concrete splitters from Darda GmbH, operating supplies directly influence power transmission, thermal balance, wear, and reliability—and thus the efficient and safe execution of a project.
Definition: What is meant by operating supplies
Operating supplies comprise all liquid and paste-like media required for the operation, lubrication, cooling, cleaning, or protection of machines and that are subject to regular inspection or replacement. These include, above all, hydraulic oils for hydraulic power packs and cylinders (i.e., hydraulic power units), lubricating greases for the joints and bearings of shears and crushers, cleaners to remove dust and residues, and corrosion protection agents. Operating supplies are not components but function-critical media that transmit energy, reduce friction, support sealing functions, dissipate heat, and protect parts against corrosion.
Operating supplies in hydraulics and cutting technology: selection and care
In the high-pressure hydraulics of concrete demolition shears, stone splitting cylinders, combination shears, multi cutters, steel shears, and tank cutters from Darda GmbH, the viscosity, cleanliness, additive formulation, and material compatibility of the hydraulic fluid govern operating behavior. Suitable oils (e.g., HLP/HVLP according to common standards) ensure low-friction power transmission, minimize cavitation, prevent stick-slip in precise cutting and splitting motions, and stabilize the temperature window. Systematic care includes correct filling, clean handling, finely tuned filtration, regular oil condition checks, and timely replacement. NLGI 2 consistency greases with strong wear and corrosion protection stabilize the bearing points of shears and crushers—crucial for reproducible cuts and controlled splitting under varying loads.
Types of operating supplies in stone and concrete processing
Hydraulic oils (HLP, HVLP, bio-based options)
Hydraulic oils serve as power carriers and lubricants. HLP oils provide proven wear and corrosion protection, while HVLP oils offer an increased viscosity index for stable viscosity across a wide temperature range—advantageous under changing outdoor temperatures on construction sites. Bio-based, rapidly biodegradable hydraulic oils can be an alternative in ecologically sensitive locations, provided they meet requirements for oxidation stability, hydrolysis resistance, and seal compatibility.
Hydraulic fluids with increased fire safety
For tasks involving heat input or ignition sources—such as tank cutting or work in areas with flammable media—water-containing HFC fluids or hardly flammable synthetic fluids are often considered. Pressure rating, lubricating film formation, and system material compatibility must be observed to maintain the desired performance of the hydraulic power packs and tools.
Lubricating greases for joints, shear bearings, and slides
Greases stabilize the kinematics of concrete demolition shears, steel shears, and combination shears. Recommended are pressure-stable greases with high mechanical stability and water resistance that provide protection even under dust exposure and splash water. The correct application quantity prevents both under-lubrication (high wear) and over-greasing (temperature spikes, seal stress).
Cleaners and corrosion protection media
Neutral to mildly alkaline cleaners remove cement dust, stone flour, and oil residues without attacking seals and coatings. Thin-film corrosion protection agents form temporary protective layers on bare surfaces and plug-in couplings—useful during interim storage, transport, or work in humid environments.
Viscosity, temperature, and pressure: fit to the application
Selection by ambient temperature
Viscosity must suit the start and operating temperatures of the hydraulics. In cold environments (e.g., rock excavation in winter, tunnel heading with low heat input), lower viscosity grades and HVLP oils ease cold starts and prevent sluggish movements. At high ambient temperatures and under continuous load, shear-stable oils with a higher viscosity index are advantageous to keep cylinder flow behavior and cutting performance consistent.
Pressure resistance and shear stability
High system pressures in stone and concrete splitters and rock splitters require additized oils with pronounced wear and extreme-pressure performance. Good shear stability prevents viscosity from dropping under cyclic loads—important for repeatability in serial cutting or splitting operations.
Cleanliness, filtration, and oil condition
Particle cleanliness and filtration fineness
Cleanliness is critical: Fine particles increase wear on valves, pumps, and cylinders, promote leakage, and shorten oil life. A filtration fineness matched to the target cleanliness level and correctly sized bypass and suction filters ensure consistent motion quality, e.g., the controlled closing of a concrete demolition shear.
Water content, air, and foaming
Water promotes corrosion and additive breakdown; entrained air leads to compressibility, foaming, and cavitation. Anti-foam additives, careful bleeding after maintenance, and low-condensation storage of containers reduce these risks.
Oil aging and additive depletion
Thermal and oxidative aging manifests as darkening, odor, viscosity drift, or varnish formation. Regular oil condition checks (e.g., neutralization number, particles, water) support planned maintenance before performance losses in hydraulic power packs or shears become apparent.
Compatibility with materials and components
Seals and elastomers
Operating supplies must be compatible with seals (e.g., NBR, HNBR, FKM, PTFE). Incompatibilities show up as swelling, shrinking, or embrittlement—visible through increased leakage or sluggish movements. When changing oil types, pay attention to miscibility and flushing concepts.
Hoses, coatings, and surfaces
Additive packages and cleaning chemistry should not attack hoses, couplings, and surfaces. Manufacturer information on cleaner concentrations and dwell times helps prevent material damage.
Practice across application areas
Concrete demolition and special deconstruction
In the context of concrete demolition and special deconstruction, varying temperatures and high load cycles argue for HVLP oils with stable viscosity and consistent fine filtration. Dust exposure makes a tightly scheduled grease maintenance regime on the joints of concrete demolition shears sensible.
Strip-out and cutting
Precise tool guidance requires shear-stable hydraulic oils and cleanly operating valves. Cleaners with good material compatibility keep cutting edges and guides free of build-up.
Rock excavation and tunnel construction
Cold starts and humidity call for low-temperature-capable oils and good water separation. Corrosion protection on uncoated steel surfaces prevents seizure due to corrosion after standstill.
Natural stone extraction
Long cycles with constant loads demand oxidation-stable oils and controlled oil temperatures. High-adhesion greases remain on exposed bearing points.
Special operations
Near heat sources or ignitable media, the use of hardly flammable hydraulic fluids can be appropriate; the system’s pressure rating and lubricating performance must be considered.
Change intervals, storage, and handling
Change and inspection intervals
Intervals depend on operating hours, load profile, temperature, and environmental conditions. Condition-based strategies (oil analytics, filter monitoring) improve planning and avoid consequential damage to cylinders and valves.
Storage conditions and shelf life
Store containers dry, dust-protected, and temperature-controlled. Use opened containers as soon as possible; consistently avoid ingress of water and dust. First-in, first-out preserves product quality.
Cleaning and filling
Clean tools and power packs before filling, use suitable fine filters when transferring, keep plug-in couplings clean, and bleed carefully after maintenance. This preserves the control precision of stone and concrete splitters and concrete demolition shears.
Signs of unsuitable or aged operating supplies
- Sluggish or jerky cylinder motions, imprecise closing of shears
- Elevated operating temperatures, rapid oil-aging odor
- Foam in the tank, cavitation, unusual pump noises
- Increased wear at bearing points, imprints or discoloration on seals
- Increasing leakage, decreasing holding force during splitting
Safety and environmental aspects
Operating supplies must be handled properly, labeled, and stored and disposed of in accordance with applicable regulations. Personal protective equipment, suitable containment systems, and avoiding mix-critical combinations increase occupational safety. Rapidly biodegradable hydraulic media can mitigate environmental impacts but must be carefully evaluated for performance and material compatibility.
Checklist for selecting operating supplies
- Clarify the application profile: temperature window, pressure level, load cycles, dust and moisture exposure
- Define the medium type: HLP/HVLP, if applicable fire-resistant or bio-based
- Select viscosity grade to match start and operating temperatures
- Define cleanliness target and filtration, specify filling and transfer technique
- Check material compatibility with seals, hoses, and coatings
- Set up a maintenance and analytics plan: oil condition, filter changes, lubrication intervals
- Consider storage and disposal concept, ensure environmental protection