text: what is eeuma 143? it may be a standard or a code for construction of shell & tube heat exchangers it is actually eemua 143.  looks like you can buy it for 25 quid.  according to their web site, it is described as below:  143 recommendations for tube end welding: tubular heat transfer equipment part-1 - ferrous materials  isbn0 85931 093 0 £25.00  date(1985) (formerly ocma spec. no. tew-1) this specification covers recommended procedures for the tube-end welding of tubes ranging from ½ in (15 mm) to 1½ in (40 mm) nominal diameter and from 1.6 mm to 4.1 mm wall thickness to tube plates of 15 mm and over in ferritic and austenitic materials.