Kink protection refers to measures and components that prevent excessive kinking of hoses, lines, or cables. In demolition and splitting technology, kink protection prevents malfunctions, leakages, and premature wear. Especially with hydraulically operated tools such as concrete demolition shears and rock and concrete splitters that are moved, set down, and frequently reconfigured in the rough everyday construction site environment, reliable kink protection is an essential part of a safe and efficient workflow.
Definition: What is meant by kink protection
Kink protection is understood to mean design elements and organizational measures that prevent exceeding the permissible bend radius on hoses, cables, or pipelines. The goal is to prevent cross-section constriction, material fatigue, crack formation, and the resulting failures. Typical designs include wire-spring kink protection, spiral protective wraps, bend radius limiters, kink-protection fittings, as well as textile- or plastic-based protective sleeves. In the environment of hydraulic tools and hydraulic power packs, kink protection supports compliance with the minimum bend radius, reduces chafing loads, and increases operational safety.
Kink protection in the hydraulic system of demolition and splitting technology
Hydraulic hose lines connect hydraulic power packs with tools such as concrete demolition shears, combination shears, or hydraulic wedge splitters. Bending, torsion, tensile load, and abrasion act on couplings, transitions, and moving line sections. Kink protection positions, supports, and guides the line so that tight radii and sharp edges are avoided. This preserves flow rate and pressure stability, and the tools operate reproducibly.
Typical loads
- Bending due to movement of the tool or the self-weight of the hose line
- Torsion when rotating and aligning the tool
- Tensile load during repositioning, lifting, or lowering
- Abrasion on edges, reinforcement, rock, and concrete debris
- Temperature changes and pressure surges in operation
Critical points on the tool
- Transition hose–fitting and coupling areas
- Guides on the cylinder and tight deflections
- Bearing points on component edges and on reinforcing steel
- Areas with recurring motion, e.g., the closing/opening range of a concrete demolition shear
Types of kink protection and their suitability
The choice of the right kink protection solution depends on medium, pressure, environmental influences, and motion characteristics. Several protection types are often combined to address bend radius, abrasion protection, and strain relief at the same time.
Wire-spring kink protection
Pushed-on or integrated spring sleeves support the hose at the transition to the fitting. They act as bend radius limiters and distribute local stresses. Suitable for dynamic areas close to the connection, for example on concrete demolition shears with frequent motion cycles.
Spiral and abrasion protection
Spiral protective wraps made of plastic or steel increase abrasion resistance and prevent localized kink formation when in contact with edges. In environments with coarse debris, reinforcement, and natural stone, they prove themselves through robust all-round protection.
Textile and plastic sleeves
Braided sleeves or textile jackets provide surface protection against chafing and UV exposure. They are light, flexible, and can be integrated into existing hose guides. In combination with bend radius limiters, they comprehensively secure the line.
Bend radius limiters and kink-protection fittings
Form parts on the fitting or red brass/steel fittings with integrated bend protection maintain the minimum radius and guide the medium with low turbulence. They reduce pressure losses and prevent microcracks in the inner layer.
Hose clamps and guides
Mechanical brackets organize hose bundles, relieve transitions, and define safe deflections. In combination with spacer strips, chafe points on the tool body and cylinder are prevented.
Selection criteria: bend radius, pressure, medium, and environment
The technical design considers both the properties of the hose line and the operating environment. A systematic approach prevents wrong decisions and increases tool availability.
- Bend radius: Compliance with the minimum bend radius under static and dynamic conditions
- Pressure and pulsation: Suitability for working pressure, pressure peaks, and load cycles
- Medium: Compatibility with hydraulic oil, possible additives, or contamination
- Temperature range: Resistance to cold, heat, and heat input at the tool
- Abrasion and cut protection: Degree of protection against sharp-edged reinforcement, rock, debris
- Installation space: Availability for safe deflections without forced tight radii
- Maintenance access: Visibility and accessibility for inspection and cleaning
Application areas: requirements for kink protection
The requirements vary depending on the task and the construction site environment. Kink protection must always be considered in the overall context of the tool, hydraulic power pack, and working method.
Concrete demolition and special deconstruction
During deconstruction, sharp-edged fracture edges and reinforcing steel act on the lines. A combined concept of wire-spring kink protection at the fittings and robust spiral protection along the hose lengths has proven itself. Concrete demolition shears produce recurring movements, which is why generous loop routing without tripping hazards is essential.
Strip-out and cutting
In buildings with narrow traffic routes, short bend radii and frequent maneuvering are typical. Bend radius limiters at couplings and light textile jackets make it easier to guide the lines without impairing flexibility.
Rock excavation and tunnel construction
Dust, moisture, and rough rock increase abrasion. Spiral protectors with high abrasion resistance and corrosion-resistant components are advantageous. Routing hoses away from contours with torsional loads reduces twisting during tool rotation.
Natural stone extraction
When using splitting cylinders and rock and concrete splitters, long line runs are common. Hose guides with intermediate supports and clearly defined deflection points prevent sagging and ground contact. Visible markings on the hose help identify kink zones.
Special applications
For atypical tasks with difficult access, modular protection solutions are helpful: retrofittable bend radius limiters, segmented spirals, and temporary supports. The priority is safe guidance and quick visual inspection.
Practical guide: routing and installation of kink protection
Professional installation ensures that kink protection performs its function permanently and does not hinder tool movements.
- Check the line: Inspect the hose for damage, aging, and correct length.
- Identify hazard points: Mark transitions, edge contacts, tight deflections.
- Select kink protection: Define a combination of spring, spiral, or textile protection depending on the load.
- Assembly at the connection: Place wire-spring kink protection over the fitting without tension.
- Add longitudinal protection: Route spiral protectors or sleeves over the stressed zones.
- Secure guidance: Position hose clamps so that sufficient play remains for movements.
- Function test: Move the tool through the full range of motion, checking for wrinkling and contact points.
- Readjust: Mitigate contact points, increase radii, adjust clamp positions.
Recommendations for hydraulic power packs
- Arrange outlets on the hydraulic power units so that the first bend forms broadly and without constraint.
- Provide strain relief at couplings to reduce micro-movements at the fitting.
- Mark line routes and keep them separate from traffic routes.
- Ensure protection from hot surfaces and exhaust gases.
Inspection, maintenance, and replacement criteria
Regular visual and functional checks prevent unplanned downtime. Anomalies should be documented early and rectified.
- Signs of kinking: Flattened bends, wrinkling, permanent deformation
- Surface damage: Chafe marks, exposed braid, cracks
- Performance indicators: Heating, pressure loss, delayed tool movement
- Protection components: Broken spiral segments, shifted springs, loosened clamps
- Replacement: In case of structural damage or repeated exceedance of bend radius limits
Documentation
Inspection intervals, findings, and measures performed should be recorded traceably. This facilitates assessment of the remaining service life and planning of spare parts.
Failure patterns and root cause analysis
Understanding typical damage patterns facilitates targeted remediation.
- Cross-section constriction: Often caused by too tight a radius; remedy with bend radius limiter
- Crack formation in the inner layer: Combination of bending and pulsation; remedy through a longer bend and spring
- Local abrasion: Contact with edges; remedy with spiral protection and modified routing
- Leakage at the fitting: Micro-movements; remedy with strain relief and rigid support
- Torsion damage: Twisted routing; remedy with twist-free guidance and markings
Impact on performance, service life, and safety
Kink protection stabilizes flow conditions and reduces pressure losses. The tool operates more predictably, switching times remain constant, and thermal loads decrease. At the same time, the service life of hose lines is extended, reducing downtime and material consumption. Occupational safety is increased because leakages and uncontrolled hose kickbacks occur less frequently.
Kink protection for concrete demolition shears: key focal points
Concrete demolition shears move in the rhythm of opening and closing, often in contact with reinforcing steel. The first hose bend on the shear body should be broad and free of interfering edges. A combination of a spring at the fitting and abrasion-resistant spiral protection along the highly loaded zones is sensible. Hose bundles must be routed so that no crushing occurs between fixed and moving parts.
Kink protection for rock and concrete splitters
Rock and concrete splitters and their splitting cylinders are frequently moved and also operated close to the ground. Hoses must not be misused as carrying aids. Generous bend radii away from the power pack, intermediate supports, and visible protective wraps prevent kink points. For long lines, an orderly bundling with defined deflection points is recommended.
Transport, storage, and preparation of hose lines
Handling outside of operation also determines service life. Incorrect coiling or setting down creates permanent kinks.
- Coil in large bends, never below the minimum bend radius
- No sharp edges, no crushing due to load securing
- Store dry, UV-protected, and without tension
- Before use, perform a visual inspection, align and secure protection components
Organizational aspects and safe working practices
Coordinated hose management increases availability and safety. Operating instructions, training, and regular inspections support the safe condition of the systems. Legal requirements may vary depending on the country of use and application; general safety rules and recognized technical standards must be observed.
Sustainability and resource conservation
Fewer hose failures mean less oil loss, less waste, and a longer useful life of components. Kink protection is therefore an effective lever for resource-conserving operation, especially with hydraulic tools with high load cycle counts.
Checklist: quick overview for the construction site
- Know and comply with the minimum bend radius
- Secure critical transitions with springs or bend radius limiters
- Equip abrasion zones with spiral protection
- Route line paths clearly, sure-footed, and free of torsion
- Inspect regularly, document, and act immediately in case of damage