In heavy machinery the hydraulic hose systems are exposed to corrosive fluids that degrade performance and safety.
This article explores causes of corrosion in hydraulic hoses and fittings, and offers solutions to prevent damage. Technical sections cover materials, coatings, maintenance, and safety procedures.
A case study shows real comparison of alternatives, implemented solutions, and results. In conclusion, the industry can significantly extend hose life by selecting the right resistant materials, cleaning after exposure, and using protective equipment.
Causes of Corrosive Fluid Exposure in Hydraulic Systems
Heavy machinery operates in harsh environments—mining, construction, agriculture, marine work. In such settings, hydraulic hoses face exposure to corrosive agents such as salt water, acids, alkaline cleaning solutions, chemical spillovers, or aggressive hydraulic fluids. When fluids with corrosive properties leak or seep into hose covers, fittings, reinforcements, or even inner tubes, they initiate chemical reactions. These reactions degrade metal wire reinforcements, fittings, or ferrous layers. Also they can break down rubber or synthetic inner lining layers, causing swelling, embrittlement, or cracking.
Corrosion can be external (fittings, clamps, hose covers) or internal (fluid contacting metal wire, poorly compatible inner tube). External corrosion weakens hose assembly, causing leaks or bursts. Internal corrosion contaminates hydraulic fluid, damages pumps, valves, seals. Corrosive fluids may include water ingress, chlorides, acids from environmental sources, or chemical additives. Temperature, pressure, fluid compatibility, and mechanical strain (bending, vibration) accelerate corrosion.
Thus in hydraulic industry, corrosion exposure is among top‐causes of failure, downtime, and replacement cost. Understanding exactly where corrosion occurs, under what conditions, and how fast, is necessary for designing long‐lasting hydraulic hose systems.
Solutions to Resist or Mitigate Corrosion
Material and Coating Selection
- Use corrosion‐resistant hose inner tubes: fluorocarbon, PTFE, specialized elastomers or synthetic rubber compounds that resist acids, alkalis, salt spray.
- Use hose covers made from materials resistant to external corrosion: synthetic rubber blends, polyurethane, chloroprene, or polymer coatings that resist weather, UV, chemicals.
- For fittings and reinforcements, choose stainless steel, brass, or plated carbon steel. Use high‐quality surface treatments: zinc plating, electroless nickel, passivation of stainless steel, galvanizing.
- Use advanced coatings: fusion‐bonded epoxy (FBE), fluoropolymer coatings, or polymer liners like ECTFE for severe chemical exposure.
Procedures for Cleaning and Flushing
- After exposure to corrosive fluid (leak or maintenance spill), flush the hydraulic fluid system thoroughly using compatible cleaning fluid. Neutralize acids or alkalis if needed.
- Clean hose covers and fittings: remove deposits, salts, chemical residues. Use appropriate cleaners that do not harm hose material.
- Perform regular inspections; identify damage early. Replace or repair hoses showing inner or outer degradation.
Personal Protective Equipment and Handling
- Require personnel to wear gloves, eye protection, face shields, and protective clothing when working with corrosive fluids or cleaning hoses.
- Use proper tools to avoid puncturing or abrading hose covers or exposing layers.
- Ensure safe handling of leaks: contain exposures, avoid skin contact, prevent drippage into hose layers.
Design and System‐Level Measures
Design routing to minimize exposure to splash, chemical runoff, or standing corrosive fluid.
Use protective sleeves or shields over hoses in areas likely to receive corrosive drips.
Select hose assemblies with sufficient pressure ratings and reinforcement to resist mechanical stresses that might expose inner materials.
Case Study
Problem Context
A large‐scale mining company uses hydraulic excavators and dump trucks. Hydraulic hoses in these machines were exposed repeatedly to acidic wash downs, salt dust, and occasional chemical spills of pH ≈2 cleaning agents. Many hoses failed prematurely: wire reinforcement corroded, inner liners softened, and fittings leaked. Frequent downtime, replacement costs, and spill hazards increased.
Parameter Comparison Table
| Parameter | Before Implementation | After Implementation |
| Hose inner tube material | Standard rubber / NBR blend | Fluorocarbon / chemical‐resistant elastomer |
| Hose cover material | Basic rubber cover, no extra coating | Polyurethane overcoat + chemical‐resistant cover layer |
| Fittings material & coating | Carbon steel with basic zinc plating | Stainless steel or carbon steel with electroless nickel or zinc‐nickel plating |
| Cleaning & flushing schedule | Reactive (only after visible corrosion) | Proactive (after every chemical exposure; periodic preventive flushes) |
| PPE & training | Minimal; workers exposed to leaks | Full PPE; training in leak containment and handling |
Implemented Solutions
The company replaced standard hoses with versions having chemical‐resistant inner tubes and enhanced covers. Fittings were upgraded to stainless steel or heavily plated steel. They introduced a flushing protocol: after any wash down or chemical exposure, systems are flushed with neutralizing agent and clean hydraulic fluid. They also trained maintenance crews to wear full PPE—including acid‐resistant gloves, eye protection, and coveralls—when handling chemical exposure. Protective sleeves were installed on hoses in high‐risk zones.
Results
- Hose lifetime increased by approximately 50%.
- Number of fit-for-reuse fittings (no leaks) rose by 60%.
- Fluid contamination reduced significantly, leading to fewer pump and valve failures.
- Maintenance cost lowered by ~30%, and downtime reduced.
- Worker safety incidents related to chemical exposure dropped to near zero.
Conclusion
In the heavy machinery hydraulic industry, exposure to corrosive fluids poses serious risk to hose assemblies and system reliability. Material choice—inner tubes, covers, fittings—and advanced coatings are first lines of defense. Regular flushing and cleaning after exposure, proactive maintenance, and procedural controls are essential. Workers must use proper PPE when handling leaks or chemical exposure. By applying these solutions, manufacturers and operators can extend hose life, reduce failures, and improve safety.
One example of a product that aligns well with these practices is Kingdaflex’s Hose, which uses corrosion-resistant materials and coatings appropriate for harsh chemical environments; it demonstrates how design and material selection can deliver real durability in the field.
