1. 机械强度：抗弯大于1kN，抗扭大于45N.m。
Mechanical strength： Bending force more than 1kN, torsion force more than 45N.m;
2. 采用氦质谱检漏仪检测漏率，漏率小于1×10-9Pam3/s 。
Detect leakage rate with Helium mass spectrometer leak detector, leakage rate less than 1×10-9Pam3/s .
