Carry out trial production of valve castings according to the improved process of the test plan. A batch of 6 valve bodies were trial-produced, and no pressure leakage occurred. At the same time, 100% radiographic inspection shall be carried out for the inlet and outlet flange positions according to ASME B16.34 standard. IR192 device shall be used for flaw detection. The transillumination method is single-wall single development, the development condition is 5 min/20 ℃, and the exposure time is 3~10 min. Radiographic inspection was carried out on the inlet and outlet flanges and neck positions of the valve body under long-term pressure, as shown in Figure 1, and the results showed that they met the standard requirements.
The test scheme is finalized in the process, and the picture after valve assembly is shown in Figure 2. After the successful trial production in small batches, 16 batches of valve bodies and 6 valves in each batch were trial-produced in large batches, all of which passed the hydrostatic test and radiographic inspection at one time, and the one-time pass rate of water hammer relief valve castings increased significantly.
