A backward-jet drain nozzle directs all or most of its water rearwards, generating reaction thrust that propels the nozzle and hose along the pipe. Typical applications include long-haul propulsion to reach a distant blockage and routine maintenance cleaning of pipe walls. The nozzle's small forward face has no cutting jets, so it does not penetrate hard blockages but will not damage fragile clay pipework. Choice of orifice size sets the balance between flow and pressure for a given jetter, and the Water Jetting Association Code of Practice provides selection guidance for safe working. Engineers carry a set of nozzles in their van pack and switch between propulsion and cutter designs depending on the diagnosis revealed by an initial CCTV survey or the response of the hose to advance.
Drain nozzle (backward jet)
Jetter nozzle with rearward jets used to propel the hose along the pipe.
