The insulating joint pig launcher drain valve is the first stop of the 4 intake valve B ball indicator tube cleaner to normal flow insulation joint pigging ball tube to the terminal station to the main line of blind plate 5 pressure safety valve discharge valve 1 3 2 valve A to serve the normal flow line to receive charge E ball valve the instrument valve 1 valve C valve F pressure gauge 3 safety valve 2 drain valve valve 4 D normal delivery process: transport medium by the first stop valve C into the main line, through valve D into the terminal station, A, B, E, the valve is in the closed state of F. Cleaning process: serve, open the quick opening of the blind plate 5 into the tube, in the different diameter pipe at the top tight, close the blind. Open the valve B; close the valve 1, 4; close the valve C, open the valve A at the same time, the pipe cleaner into the main pipe, the work began to clear the pipe. When receiving the ball, the Qing pipe device to reach the ball before an hour or so to close the valve D, open the valve E, F and valves 1, 4. In recognition of the tube into the ball after receiving the ball valve to open the valve D, close the valve E and valve F, after all the pressure of the cylinder to be completed and then open the blind plate 5, remove the tube, the end of the Qing dynasty.