1. The internal and external leakage of the hydraulic system leads to no pressure test: the internal leakage in the middle of the second chamber of the hydraulic system lies in the stability of the piston rod sealing equipment. The general stability from large to small is: soft plastic sealing ring > hard pig iron engine piston sealing > gap sealing. Improving the production precision and mutual cooperation precision of hydraulic system cylinder hole, piston rod and hydraulic cylinder is conducive to reducing the common faults of poor pressure test caused by internal and external leakage.

2. Leakage of pressure regulating valves: especially the leakage size of the hydraulic directional valve of 3600t copper based powder forming hydraulic press close to the hydraulic system is the main factor leading to whether the pressure test is or not. The leakage of hydraulic solenoid valve lies in the structural form and manufacturing precision of the valve. Therefore, the actual effect of pressure test with cone valve (such as hydraulic control one-way valve and logic valve) is much better than that with rotary vane pump. This foreign affairs must improve the processing accuracy and installation accuracy of the valve. Even the valve with spherical sealing also needs to pay attention to the accuracy of the mating parts of its cylinders and the stability of spherical sealing.

3. The method of continuous oil replenishment is selected to continuously replenish the leakage of the system software of 3600t copper based powder forming hydraulic press in the whole process of pressure test. Although it is relatively depressed, there is no practical way when the pressure test time must be long. This method can keep the working pressure of the hydraulic system unchanged.