directed within the plane of rotation of the spray arms 60 and 62 to impart an angular momentum by a jet of water or cleansing liquid exiting the assembly the retainer 64 of rotary union 50 can be seen affixed at a point on spray arms 60 and 62 so that spray nozzles 108 and 110 will be equidistantly placed from retainer 64 spray nozzles 108 and 110 are preferably suited to high pressure washing such as the commercially available washjet u00ae high impact solid stream nozzle available from spraying systems co of wheaton illinois this placement at opposing ends of the spray arms 60 and 62 is advantageous since it obviates the need for motorized propulsion which has a propensity for breakdown in the preferred sub zero or otherwise adverse environment to which these devices are frequently exposed to ensure maximum coverage of the coil surfaces the nozzles 108 and 110 can be accompanied by a plurality of smaller spray nozzles 112 and 114 the number of which is dependent upon the length of the spray arm 60 or 62 it is suggested from experiments that a large number of small nozzles performs better than a lesser quantity of large nozzles the plurality of smaller nozzles 112 and 114.