The Plastic Pipe Institute (PPI) has issued a revision to TN-61, Coilable HDPE Conduit Ovality and Coil-Set. This paper addresses ovality and coil-set of HDPE conduit and CIC (cable in conduit) caused by coiling. This write up gives an excellent explanation of what ovality and coil-set is, what causes it, and how to mitigate it during installation. You can read the full published article
here. For more information on HDPE conduit please contact your Blue Diamond sales representative at 859-224-0415 or find their email
here.