Atlantium MP0023000 — O-ring, size AS568-327 (inside diameter 43.82 mm x cross-section 5.33 mm; 1.725 in x 0.210 in), FKM (fluorocarbon), 70 Shore A, compound V0680-70; location: quartz sleeve (RZ series quartz sleeve). Sealing elements are replaced at every lamp or quartz service, because elastomers take a compression set at the operating temperature of a medium-pressure lamp. Fit dry or with a UV-system-approved lubricant and confirm the groove is free of scale before assembly. Spare part for Atlantium Technologies Hydro-Optic (HOD) UV water disinfection systems, which use medium-pressure lamps, a quartz treatment chamber working by total internal reflection, one UV intensity sensor per lamp and continuous UV-transmittance monitoring; installed in aquaculture, dairy and beverage process water, municipal drinking water, power-plant and industrial water treatment.