Method for trench-free forming of pressure-sealed domestic gas/water pipe connections uses robots to place whip stock, drill string with head, draw head, and milling cutter robots

摘要

The method uses robots moving inside the pressure pipes. An angled whip stock is fitted into the main pipe in front of the branch-off of the house pipe to be connected. A drill string with drill head is inserted into the main pipe, and drills to the connection point. A draw head is fastened to the end of the house pipe, connected to the drill string, and retracted into the main pipe, until the draw head projects into the main pipe, and the house pipe end is connected to the main pipe. The whip stock is removed and a milling cutter robot cuts off the draw head part projecting into the main pipe. The drill string is removed and the connection point is sealed. A second milling cutter with smaller diameter cuts a sickle-shaped section out of the main pipe wall, and cuts smooth all projecting pipe parts. A formed part with opening is fitted into the cut-out with its opening aligned with the rest of the draw head, and welded pressure-sealed to the pipes.