O-ring set, part 180007-0047, for Hanovia medium-pressure ultraviolet disinfection systems built around the 47 mm quartz sleeve. The set gathers the O-rings disturbed when the sleeve is withdrawn, so a sleeve change can be completed without ordering seals individually. The 0047 suffix is the sleeve diameter in millimetres — the equivalent set for 38 mm systems is 180007-0038-01. The PTFE ring 49 × 38.3 mm belonging to this set is catalogued separately. Reference number 2248-0907.