Abstract: A pipe is bent by advancing the pipe through a guide and into a ring disposed just upstream of said guide in the direction of pipe movement. The ring with the leading end of the pipe therein is moved by a controller along a predetermined curve along which the pipe is to be bent.

Abstract: A process for the production of a low-sulfur diesel gas oil having a sulfur content of 0.05% by weight or lower and having a Saybolt color number of -10 or higher, from a petroleum distillate having a sulfur content of 0.1 to 2.0% by weight and having an inferior color and inferior oxidation stability comprises contacting the petroleum distillate with hydrogen in the presence of a hydro-treating catalyst which has at least one metal supported on said porous carrier, at a temperature of 350.degree. to 450.degree. C., and a pressure of 45 to 100 kg/cm.sup.2 in the first step to thereby produce materials having a sulfur content of 0.05% by weight or lower, and contacting further the materials issued from the first step with hydrogen in the presence of a hydro-treating catalyst which has at least one metal supported on said porous carrier, at a temperature of 200.degree. to 300.degree. C., and a pressure of 45 to 100 kg/cm.sup.2 in the second step to thereby produce the finished low-sulfur diesel gas oil.