Is there a significant reduction of pipe structure integrity?
We have not seen any indication that our rerounders reduce the pipe integrity. We have seen testing that indicates that if the deflection is greater than 30%, the initial deflection can cause permanent structural damage. In all of the rerounding projects that we have been directly involved with, the deflections encountered have been less than 30%. The rule of thumb that we use for checking excessive deflection is to pull the next size smaller deflection gauge through the pipe. For example use a 6 inch gauge in an 8 inch pipe. If the 6 inch gauge does not go through, then the integrity of the pipe should be evaluated. In our experience, that much deflection would be rare.
