A hydraulic breaker (also called a hydraulic hammer) is one of the most common attachments on an excavator. In mining, demolition and road maintenance it converts hydraulic energy into high-frequency impact. It is also the most violently loaded end of the entire hydraulic system: the hose must withstand rapidly surging pressure pulses while rubbing against rock and rebar. Many owners find that a hose lasting two or three years elsewhere wears through, leaks or even bursts within three to five months on a breaker. This article presents a practical selection and maintenance method covering parameter tables, structural selection, outer-cover wear resistance and on-site protection.
1. Three Harsh Tests a Breaker Puts on the Hose
- High-pressure impulses: a breaker strikes several times per second, and the system pressure surges up and down repeatedly at millisecond level; the hose endures impulse fatigue far beyond steady-state conditions - several times that of ordinary lines.
- Shock and vibration: the breaker reaction force transmits through the boom, and the hose bends and chatters in follow-up motion; fittings loosen and leak easily, and the crimped joint is the weakest point.
- External abrasion: the hose often rubs against the bucket, rock and rebar; once the outer cover is worn through and the wire layer exposed, the whole hose is scrapped - this is the number-one reason breaker hoses retire early.
2. Match the Table First: Pressure and Flow Determine the Bore
The first step in selection is to compare the breaker and excavator auxiliary-circuit parameters - never just go with close enough:
- Operating pressure: small hammers about 90-120 bar, medium 120-170 bar, large 170-200+ bar; selection must take the excavator auxiliary-circuit relief-valve pressure as the hard upper limit.
- Flow: small 15-60 L/min, medium 40-140 L/min, large 150-400+ L/min; excessive flow causes overheating, pressure drop and weak impact.
- Hose bore: grows with hammer size from 1/2 in, 3/4 in to 1 in, 1-1/4 in, and must match the quick-change coupling and boom pass-through dimensions.
- Basic principle: the hose rated working pressure must be at or above the system relief pressure, and leave enough margin for impulse duty - not just meet steady-state pressure.
3. Structural Selection: Breakers Prefer EN 856 Spiral-Wire Hose
- Braided hose (EN 853 1SN/2SN): impulse life about 150,000-200,000 cycles, suitable for medium pressure, frequent bending and tight spaces (e.g. short boom follow-up lines).
- Spiral-wire hose (EN 856 4SP/4SH): impulse 400,000+ cycles (4SH often reaches 500,000), burst ratio 4:1, designed specifically for severe-impulse duty like breakers; parallel, non-crossing wires give better fatigue resistance.
- Combination advice: use 4SP/4SH for the main supply line (pump to hammer); use 2SN only for space-limited follow-up sections to avoid using the fatigue-prone braided hose throughout.
- KUNGFLEX supplies the full EN 853 / EN 856 hose range and crimped assemblies, selected and supplied to standard - no unsubstantiated parameter promises.
4. Outer-Cover Wear Resistance: Look for ISO 6945 and Reinforced / PU Covers
- ISO 6945 method: drag the pressurized hose back and forth on a standard abrasive and record the cycles until wear through to the first wire, used to compare outer-cover quality across products (it does not predict absolute life, but tells the good from the bad).
- Wear grades: a standard rubber cover is about the 50,000-cycle level; reinforced wear-resistant covers can reach 50-100 times that; PU (polyurethane) covers are the highest (hundreds of times), and are non-fading, low-friction and UV-resistant, suiting ground-rubbing sections.
- In practice: for breaker hose sections that drag on the ground or bucket, prefer reinforced wear-resistant or PU covers; if needed, add a spring guard or abrasion sleeve - cheaper than frequent hose changes.
5. Five On-Site Protection Points
- Routing: keep the hose at least a fist distance from rock and bucket edges, secure it with clamps/sleeves, and avoid repeated rubbing against hard objects.
- Bend radius: no smaller than the manufacturer minimum bend radius; a hard bend flattens the inner layer and separates the outer wire, sharply cutting life.
- Anti-twist: axial twisting is strictly forbidden during installation - a 7 degree twist alone can cost nearly 90 percent of service life.
- Fittings: choose crimped fittings matched to system pressure and check for leaks regularly; KUNGFLEX can supply crimped assemblies and burst-test reports.
- Inspection: before each shift check whether the outer cover is fraying, wires exposed or leaking; replace as soon as the cover is worn through - never wait until it leaks.
6. Breaker Hose Selection Checklist
- Rated pressure at or above system relief pressure; main supply uses EN 856 4SP/4SH (impulse 400,000+ cycles)
- Bore and flow matched to hammer type and excavator auxiliary circuit
- Outer cover: reinforced wear-resistant or PU (prefer higher ISO 6945 grade)
- Routing avoids friction, keeps enough bend radius, strictly prevents twisting
- Crimped fittings pressure-matched + pre-shift inspection for exposed wire/leakage
- Prefer assemblies supplied with factory burst/impulse test reports
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About Shanghai Beirun Hydraulic Equipment Co., Ltd. (KUNGFLEX)
Shanghai Beirun Hydraulic Equipment Co., Ltd. (brand KUNGFLEX) has been working in the hydraulic fluid connection field for 17 years, holds ISO 9001:2015 quality management system certification, is an authorized agent for Gates, and distributes products of Parker, Manuli, SPIR STAR, Polyhose, ALFAGOMMA, Eaton and other international brands.
- Core testing capability: 4000 kg / approx. 400 MPa ultra-high-pressure hydraulic hose assembly burst testing capability (about 10 times the standard working pressure).
- Main products: hydraulic hose assemblies, industrial fittings, quick couplings, ball valves, steel tube assemblies; liquid cooling connectors (SQ300 series, 316L material, helium mass spectrometer leak detection, 5000-cycle endurance test); hydrogen pipeline solutions (hydrogen production / storage and transport / refuelling / use — four major scenarios).
- Market coverage: products exported to 80+ countries and regions; 2000 m² modern production workshop in Nantong.
- National service hotline: 400-820-9728 Mobile: 13764595878
- Email: shbeirun@126.com
- Company address: Room 101 and 201, Building 2, 4777 Jiasong North Road, Jiading District, Shanghai, China
