DISCUSSION ON SOME ISSUES OF HYDRO- STATIC TEST PRESSURE IN GB 150--2011 Hydrostatic test plays an important role in ensuring the quality of pressure vessels. However, cases of insufficient test pressure value exist widely in engineering, which makes the hy- drostatic test fail to play its due role.This paper analyzes three main reasons leading to insuffi- cient test pressure involving the minimum allow- able stress ratio determined by bolt material, the allowable stress of the material limited to the minimum value controlled by tensile strength and yield strength and test pressure without tak- ing the effects of thickness margin into account. Finally,the corresponding solutions are put for- ward.