Control and inspect whole production process strictly, every part and each tool is traceable and in serial. Simple description is as following:

1.Quality control of steel material. Select good mill factory, third test center for steel sample testing.

2.O-rings and Backup seals are all 100% visual and dimensional inspection.

3.Spare parts production control, QC inspection after each production process; high requirements of Heat treatment or Surface treatment inspection.

4.Tool Assembly and test process, QC is inherent with foreign company’srequirements.