380 Compressed-air reservoir identification plates formed on the pressure-bearing walls of the reservoir (casing, base, ring nuts). the internal supply pressure may exceed maximum operating pressure P s by not more than 10% for a brief period. Compressed-air reservoir identifica- tion plates Example: identification plate on the steel reservoir : Manufacturer ; MB part number = Maximum operating pressure (bar) ? Volume (litres) A Year of manufacture B Testing establishment code number Technical data