BS EN 303-1-2017 实施日期:2017-09-21 英文名:Heating Boilers. Heating Boilers With Forced Draught Burners. Terminology, General Requirements, Testing And Marking BS EN 16282-5-20
DIN EN ISO 15614-1-2017 实施日期:2017-12-01 英文名:Specification and qualification of welding procedures for metallic materials - Welding procedure test - Part 1:Arc and gas welding of ste