Water-soluble pipe-plugging device and pipe plugging method thereof

A water-soluble pipe-plugging method for a water-soluble pipe-plugging device, comprising the following specific steps:

• (a) Cutting off, through cold cutting, a part of a first pipe to be replaced or repaired, thereby forming a first side and a second side of the first pipe separated by a cut;
• (b) Using a wiping rag to clean the inner wall of the first pipe at both sides until there is no grease or dirt;
• (c) Determining a position for installing the water-soluble pipe-plugging device where the water-soluble pipe-plugging device temperature is below 60° C. according to heat conduction generated from a welding location during welding, and drawing a line on the inner wall of the first pipe at both sides;
• (d) Spreading a ring of a water-soluble glue at the position of the line on the inner wall of the first pipe at both sides, respectively;
• (e) Selecting two water-soluble circular plugging plates of a diameter corresponding to the inner diameter of the first pipe, wherein the diameter of the circular plugging plates is slightly greater than the inner diameter of the first pipe;
• (f) Pushing one of the circular plugging plates into the first pipe at each of the first side and second side, such that an edge of each circular plugging plate rests tightly fits against the ring of water-soluble glue spread in step (d);
• (g) Securing several water-soluble support plates with water-soluble glue onto a surface of the external side of the two circular plugging plates, respectively, wherein outer side faces of the support plates are disposed flush with an outer side face of each of the circular plugging plates and wherein each of the support plates are oriented with a longitudinal axis coinciding with a radius of each of the circular plugging plates;
• (h) Bonding each support plate to the inner wall of the first pipe at both sides, respectively;
• (i) Pushing a second pipe into the cut from step (a);
• (j) Welding the second pipe to the first pipe.