EN250 Respiratory equipment - Open-circuit self-contained compressed air diving apparatus - Requirements, testing and markingEN 250 Normative references EN 144-1, Respiratory protective devices - Gas cylinder valves - Part 1: Thread connections for insert connector EN 148-1, Respiratory protective devices - Threads for facepieces - Part 1: Standard thread connection EN 148-2, Respiratory protective devices - Threads for facepieces - Part 2: Centre thread connection
EN62321