Hydraulic Hose Selection: Pressure, Temperature, and Compatibility

Hydraulic hose failure is one of the most common causes of unplanned downtime in industrial systems. Correct hose selection requires attention to three primary factors: working pressure, temperature range, and fluid compatibility.

Pressure Rating

The fundamental rule: the hose working pressure must exceed the maximum system pressure, including pressure spikes.

• Static systems: Select hose with 4:1 safety factor (burst-to-working ratio)
• Dynamic systems: Consider impulse pressure ratings — standard burst ratings are insufficient
• Accumulator circuits: Account for rapid pressure fluctuations

Temperature Considerations

Ambient and fluid temperature directly affect hose life:

• Standard rubber hose: -40°C to +100°C
• Thermoplastic hose: -40°C to +70°C (lower max but better chemical resistance)
• PTFE-lined hose: -55°C to +230°C (for extreme applications)

Every 10°C above the recommended temperature halves the hose service life. This is not a guideline — it is a physical reality.

Fluid Compatibility

Not all hoses are compatible with all hydraulic fluids:

| Fluid Type | Standard Rubber | Thermoplastic | PTFE | |---|---|---|---| | Mineral oil | ✓ | ✓ | ✓ | | Water glycol | ✓ | ✓ | ✓ | | Phosphate ester | ✗ | Limited | ✓ | | Biodegradable | Check rating | Check rating | ✓ |

Routing Best Practices

Proper routing extends hose life significantly:

1. Maintain minimum bend radius — never kink or force a tight bend
2. Allow for length changes (hoses can contract up to 4% under pressure)
3. Protect from abrasion with spiral guards or sleeves
4. Support long runs to prevent sagging
5. Keep away from heat sources and moving parts