Pneumatic quick fittings are widely adopted in automatic handling and stamping stations. PP plastic fittings crack within 3 months under cutting fluid immersion, nickel-plated copper fittings withstand high temperature with higher cost, modified PU balances oil resistance and cost. Wrong fitting selection leads to continuous air leakage and frequent line downtime.
| Fitting Material | Long-term Operating Temp Range | Cutting Fluid & Oil Resistance | Standard Service Life (Clean Dry Workshop) | Cost Level | Forbidden Scenarios |
| PP Polypropylene Plastic | 0~60℃ | Poor, swelling & crack when contacting cutting fluid | 8 months | Lowest | Machine tool processing, welding high temp stations, oil workshops |
| Modified PU Plastic | -10~80℃ | Good, resistant to light cutting fluid & lubricant | 14 months | Medium | Sealed equipment interior over 100℃ long-term |
| Nickel-plated Copper Base | -20~120℃ | Excellent, fully resistant to machine oil & cutting fluid corrosion | 36 months | Highest | Food clean production lines with metal debris pollution risk |
1. Machine tool & stamping oil workshops: Nickel-plated copper quick fittings mandatory to resist long-term cutting fluid immersion corrosion; 2. 3C electronic & food packaging dust-free lines: Modified PU plastic fittings to avoid metal debris contaminating workpieces; 3. Normal temperature dry simple conveying lines: PP plastic fittings to cut MRO procurement cost significantly; 4. High-temperature stations near welding equipment: Only nickel-plated copper fittings available, plastic fittings soften and leak under heat.
1. Cut air hose smoothly without burrs, fully insert to the bottom of fitting spring clip and pull lightly to confirm locking; 2. Wrap half circle of PTFE tape on threaded fittings, apply moderate torque to prevent thread slipping and fitting cracking; 3. Annual replacement cycle: PP fittings every 8 months, PU every 14 months, nickel-plated copper every 3 years.