# The Gas Safety (Installation and Use) Regulations 1998, Regulation 25: Interpretation of Part E

Extent: E+W+S

In this Part—
“flue pipe” means a pipe forming a flue but does not include a pipe built as a lining into either a chimney or a gas appliance ventilation duct;
“operating pressure”, in relation to a gas appliance, means the pressure of gas at which it is designed to operate.

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Source: https://www.legislation.gov.uk/uksi/1998/2451/regulation/25 (the official version)
Page: https://openlegislation.uk/gas-safety-installation-and-use-regulations-1998/regulation-25
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.