# The Pressure Equipment (Safety) Regulations 2016, Paragraph 36: Allowable stresses


(1) In paragraph 37, the following symbols have the following meanings—
(a) Re/t, yield limit, indicates the value at the calculation temperature of—
(i) the upper flow limit for a material presenting upper and lower flow limits,
(ii) the 1.0 % proof strength of austenitic steel and non-alloyed aluminium,
(iii) the 0.2 % proof strength in other cases.
(b) Rm/20 indicates the minimum value of the ultimate tensile strength at 20oC.
(c) Rm/t designates the ultimate tensile strength at the calculation temperature.

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Source: https://www.legislation.gov.uk/uksi/2016/1105/schedule/2/paragraph/36 (the official version)
Page: https://openlegislation.uk/pressure-equipment-safety-regulations-2016/schedule-2/paragraph-36
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.