prBAS EN 12953-1:2026

This document applies to shell boilers with volumes in excess of 2 l for the generation of steam and/or hot water at a maximum allowable pressure greater than 0,5 bar and with a temperature in excess of 110 °C. For the purpose of this document the following pressurized parts are included: — the shell boiler as one entity of pressure equipment including all the pressure parts from the feedwater/hot water inlet (including the inlet valve) up to and including the steam/hot water outlet (including the outlet valve or, if there is no valve, the first circumferential weld or flange downstream of the shell boiler or if applicable the outlet header); — all superheaters, economizers and interconnecting piping; — additionally, the piping that is connected to the boiler involved in services such as draining, venting, desuperheating, etc., up to the first isolating valve or, if there is no valve, the first circumferential weld or flange downstream of the shell boiler or if applicable the outlet header/piping. This document does not apply to the following types of boilers and equipments: a) water-tube boilers; b) non stationary boilers, e.g. locomotive boilers; c) thermal oil boilers; d) boilers where the main pressure housing is made of cast material; e) pumps, gaskets, etc; f) brickwork setting and insulation, etc. NOTE 1 Further information on shell boilers is given in Annex A. NOTE 2 Stainless steel boilers are covered by EN 14222:2021.