SCHEDULE 1Essential Safety Requirements
PART 1Materials
Steel vessels5
Non-alloy quality steels must meet the following requirements—
a
they must be non-effervescent and supplied after normalisation treatment, or in an equivalent state;
b
the content per product of carbon must be less than 0.25% and that of sulphur and phosphorous must each be less than 0.05%
c
they must have the following mechanical properties per product—
i
the maximum tensile strength Rm, max must be less than 580 N/mm2;
ii
the elongation after fracture must be:
if test pieces are taken parallel to the direction of rolling:
thickness ≥ 3 mm: | A | ≥ 22%, |
thickness < 3 mm: | A 80 mm | ≥ 17%, |
or, if test pieces are taken perpendicular to the direction of rolling:
thickness ≥ 3 mm: | A | ≥ 20%, |
thickness < 3 mm: | A80 mm | ≥15%, |
iii
the average bending rupture energy (KCV) for three longitudinal test pieces at minimum working temperature must not be less than 35 J/cm2. Not more than one of the three figures may be less than 35 J/cm2, with a minimum of 25J/cm2. In the case of steels intended to be used in the manufacture of vessels the minimum working temperature of which is lower than - 10°C and the wall thickness of which exceeds 5 mm, this property must be checked.