# The Iran (Sanctions) (Nuclear) (EU Exit) Regulations 2019, Paragraph 37: Section 2A: Equipment


(1) Tubes with an outer diameter of 0.2 m or more and made from any of the following materials—
(a) stainless steels with 23% chromium or more by weight;
(b) stainless steels and nickel bases alloys with a pitting resistance equivalent number higher than 33.
(2) In sub-paragraph (1)—
(a) the “pitting resistance equivalent” (“PRE”) number characterises the corrosion resistance of stainless steels and nickel alloys to pitting or crevice corrosion;
(b) the pitting resistance of stainless steels and nickel alloys is primarily determined by their compositions, primarily: chromium, molybdenum, and nitrogen;
(3) The formula to calculate the PRE number is—
PRE =% Cr + 3.3*% Mo + 30*% N

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Source: https://www.legislation.gov.uk/uksi/2019/461/schedule/1a/paragraph/37 (the official version)
Page: https://openlegislation.uk/iran-sanctions-nuclear-eu-exit-regulations-2019/schedule-1a/paragraph-37
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.