1. High pressure oil pipe 120h vibration test 10 million times, pulse test> 2.1 million times without deformation or cracking;
2. Cleanliness <25mg/m2;
3. Able to withstand high pressure>135Mpa;
4. Salt spray test: 500 hours for painted surface and 30 hours for bare surface;
5. The flatness rate of elbows <1.05;
6. Anti-fatigue: random vibration test, impact test, no cracks, no leakage.