Hose quick coupling. PIUSI has developed a new quick coupling that is suitable for use with diesel. In the past, quick couplings for use with diesel derived from quick couplings that were intended for use with oil, where the bores on the interior were too small for the diesel supply flow. With this quick coupling, this issue does not come into play. Here the bore has been designed to minimize resistance in the presence of high flow rates during the supply of the diesel.