These weld-type sight glass fittings, complete with glass disc, seal gasket, and cushion gasket bolted between circular flanges, is the low-pressure version of the DIN28120. The units can be combined with Lumiglas luminaires, such as the USL05-Ex, USL06-Ex, USL07-Ex or USL08-Ex, for use in hazardous areas. Under all normal working conditions, light options include USL01, USL13, USL15, USL05, USL06, or USL07. For an integral light/sight port, combine the low pressure unit and LumiStar light. Options include sightglass wipers type SW I .