Counterboring is a method used to create an even surface on the inside wall of a pipe end. The process to make piping often results in an uneven surface on the inside wall. When joining two pipes together, the uneven surface creates gaps, which are difficult to weld.
Counterboring prepares the pipe ends by machining so that the joint seals tightly and can be welded easily.
Trenchlesspedia Explains Counterboring
Counterboring machines fit onto the end of a pipe. They create a smooth and even surface on the inner wall of the pipe where one pipe will fit into another to create a join. Edges can be beveled to allow for a larger surface area in the join and a more secure weld. Joining pipe segments is very important in trenchless projects because weld defects delay the project while repairs are carried out.
Welds can be tested by hydrostatic pressure tests or x-rays. In a worst-case scenario, the pipe may fail after installation resulting in expensive repairs.