Large-scale and high-head pumped storage units also adopt hydrostatic test to eliminate the stress and inspect the welding quality, further to test the deformation water distribution ring (volute).

• 大型中高水头抽水蓄能机组也采用水压试验来有效消除蜗壳焊接过程中的应力并检查焊接质量，同时检验蜗壳充水后的变形规律。