# The Gas Safety (Management) (Amendment) Regulations 2023, Regulation 14: Amendment of Schedule 3

Extent: E+W+S

(1) Schedule 3 (content and other characteristics of gas) is amended as follows.
(2) In Part 1—
(a) in the table following paragraph 1—
(i) in the entry for “oxygen content”, for “≤0.2% (molar)” substitute “≤1.0% (molar), where the gas is conveyed in a pipe operated at a pressure of ≤38 barg, and ≤0.2% molar, where the gas is conveyed in a pipe operated at a pressure of >38 barg”;
(ii) in the entry for “impurities”, for “the 1994 Regulations” substitute “the 1998 Regulations”;
(iii) in the entry for “hydrocarbon dew point and water dewpoint”, for “the 1994 Regulations” substitute “the 1998 Regulations”;
(iv) after that entry insert—
“
RD
≤0.700
”;
(v) in the entry for “WN”, for “≥47.20 MJ/m3” substitute “≥46.50 MJ/m3”;
(vi) omit the entry for “ICF”;
(vii) omit the entry for “SI”;
(b) in paragraph 3, for “the 1994 Regulations” substitute “the 1998 Regulations”;
(c) in paragraph 4 omit sub-paragraph (2).
(3) In Part 2—
(a) in paragraph 1—
(i) omit sub-paragraph (b);
(ii) after that sub-paragraph insert—
“(c) RD ≤0.700”;
(b) in paragraph 2 omit sub-paragraph (2).
(4) In Part 3—
(a) in paragraph 1—
(i) omit the definition of “C3H8”;
(ii) omit the definition of “equivalent mixture”;
(iii) omit the definition of “ICF”;
(iv) after that definition insert—
““gross calorific value” means the gross calorific value, expressed in MJ/ m3, of a dry gas determined on the basis that the water produced by combustion is assumed to be condensed;”;
(v) in the definition of “mg/m3” for “at 15C and 1.01325 bar” substitute “under the reference conditions”;
(vi) for the definition of “MJ/ m3” substitute—
““MJ/ m3” means megajoules per cubic metre under the reference conditions;”;
(vii) omit the definition of “N2”;
(viii) omit the definition of “PN”;
(ix) for the definition of “relative density” substitute—
““relative density” (“RD”) means the ratio of VG to VA (expressed in the same units) where—
VG is the mass of a volume of the gas when containing no water vapour under the reference conditions; and
VA is the mass of the same volume of air containing no water vapour under those conditions;”;
(x) omit the definition of “SI”;
(xi) for the definition of “WN” substitute—
““WN” means the Wobbe Number of the gas, which is calculated in accordance with the following formula—”;
gross calorific value÷relative density
(xii) omit “trigonometric functions are to be evaluated in radians.”;
(b) after paragraph 1 insert—
“1A. In this Schedule, the reference conditions are 15C and 1.01325 bar.”;
(c) omit paragraph 2.

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Source: https://www.legislation.gov.uk/uksi/2023/284/regulation/14 (the official version)
Page: https://openlegislation.uk/gas-safety-management-amendment-regulations-2023/regulation-14
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.