ANSI/CAN/UL 795:2024

Scope 1.1 These requirements apply to factory-built gas-fired package boilers having input ratings of more than 400,000 Btu/h (117,228 W), per individual combustion chamber, having the following: a) For the United States: Inlet/supply pressures up to 15 psi (103 kPa), and intended primarily for commercial and industrial installation; b) For Canada: Inlet/supply gas pressures ?0.5 psi (3.4 kPa) up to 15 psi (103 kPa) and intended primarily for commercial and industrial installation. 1.2 These requirements also apply to all high pressure steam and high temperature water gas-fired boiler assemblies regardless of Btu/h (kW) input or inlet/supply pressure. 1.3 Package boilers covered by these requirements are designed to be automatically operated without a competent attendant being constantly on duty at the burners while the appliances are in operation. 1.4 Package boilers covered by these requirements are intended for connection to electrical supply circuits limited to 600 V ac or less. 1.5 Boiler assemblies covered by the requirements of this standard are intended for the following fuel gases, as applicable to the manufacturer’s rating: a) Natural gas; b) Hydrogen-natural gas blendsa; c) LP-gas; d) LP-Gas/Air blends; and e) Manufactured gas. a Up to 25 % H2 and 75 % natural gas blend shall be the limit for the purposes of this standard. 1.6 Additional installation and operation requirements are available for commercial-industrial gas-fired package boilers as defined by: a) In the United States: 1) The National Fuel Gas Code, NFPA 54; and 2) The Liquefied Petroleum Gas Code, NFPA 58, as applicable. b) In Canada: The Natural gas and propane installation code, CSA B149.1. 1.7 These requirements also apply to furnaces and air heaters (United States only) having input ratings of more than 400,000 Btu/h (117,228 W), per individual combustion chamber, having inlet/supply gas pressures up to 15 psi, and intended primarily for commercial and industrial installation. Annex A shall be used to evaluate furnaces and air heaters (United States only). All requirements of this standard apply unless modified by this Annex.