DIN EN 12178:2017-03

This European Standard specifies safety requirements, safety factors, test methods, test pressures and marking of liquid level indicating devices, referred to throughout this standard as "level indicators", for use in refrigerating systems and heat pumps. It applies to devices connected to refrigerant vessels (for example, on high-pressure liquid receivers, intercoolers and low-pressure receivers) and to devices connected to other parts of a refrigerating system (such as oil-level sight glasses on a compressor). This European Standard applies to those types of level indicators that are direct and indirect reading devices (for example, sight glasses, frosting tubes), and includes electrical and pneumatic indicators. This European Standard describes the procedure to be followed when designing (by calculation or by an experimental design method) level indicator parts subjected to pressure as well as the criteria to be used for the selection of materials. This European Standard applies to the design of level indicators with respect to pressure containment and describes methods by which the reduced impact values at lower temperatures may be taken into account in a safe manner. It also gives guidance on some aspects of application and installation. This document (EN 12178:2016) has been prepared by Technical Committee CEN/TC 182 "Refrigerating systems, safety and environmental requirements", the secretariat of which is held by DIN, Germany. Regarding the German collaboration, Working Committee NA 044-00-01 AA "Sicherheit und Umweltschutz" ("Safety and environment protection") at DIN Standards Committee Refrigeration Technology (FNKä) is responsible.