Pipe Insulation Inner Diameter Dorn Set (PID) Pipe insulation - PID Pipe insulation inner diameter dorn set Pipe insulation – the PID simpleuse dorn meassurement set consisting of 9 dorns ranging from 10 to 55mm, with 0.5mm steps. Specifications PID 10mm-55mm Weight 10 kg Max outer diameter 55 mm Min inner diameter 10 mm Standards EN 13467 Thermal insulating products for building equipment and industrial installations – Determination of dimensions, squareness and linearity of preformed pipe insulation