The DDT® Pigg – a compliant and flexible cleaning device – is the key to the DDT® Process. This polymer Pigg, available in diameters from 1 to 36 inch, will negotiate short radius elbows, plug headers and U-bends, obstacles that have long out performed conventional piggs. DDT® Piggs are the only Piggs designed to incorporate an array of interchangeable appendages threaded into the Pigg body which allows the cleaning heads to be adapted to suit any conditions encountered in refinery heaters.