DIN 7079:2025-08

This document applies to circular glass-to-metal fused sight glasses in which the viewing pane is fused into a metal ring. These may be used in flanged mountings in accordance with DIN 28120 (force-fit connection) or in flow sight glasses in accordance with DIN 11869. The installation dimensions of the sight glasses according to this document correspond to the dimensions specified in DIN 7080. Circular glass-to-metal fused sight glasses according to this document also fit into round sight glasses with holders according to DIN 28121 (force bypass connection) (see also DIN 28121:2021-04, 4.4). When used within the scope of the Pressure Equipment Directive (Directive 2014/68/EU), these are to be considered components of the pressure equipment. The operating range of the sight glass plate shall fall within the operating range of the pressure equipment. This standard has been prepared by Working Committee NA 178-01-03 AA "Anlageteile" ("Process equipment") at DIN Standards Committee for Process and Plant Technology (NAPA).