Diameter of Reamer (d2)
Definition - What does Diameter of Reamer (d2) mean?
Diameter of reamer refers to the measurement of the diameter of a reamer tool at its widest point. A reamer is used during a horizontal directional drilling (HDD) project to enlarge the size of the bore. The diameter of reamer is important because the final diameter of the bore needs to be opened to 1.5 times the size of the pipe.
Trenchlesspedia explains Diameter of Reamer (d2)
Horizontal directional drilling (HDD) involves the drilling of a pilot hole using a drilling rig. Once the drilling head reaches the destination point, it is removed from the drill string and replaced with a reamer. The drilling rig then pulls the reamer back through the bore, enlarging its diameter as it does so. If the diameter needs to be enlarged significantly, a number of passes may be required, each time with a larger reamer. The diameter of the reamer for the final pass must be 50% larger than the product pipe diameter in order to accommodate pipe pullers in the bore, as well as minimizing the stresses on the pipe as it is placed in position.