CSA B149.3:25

Preface This is the seventh edition of CSA B149.3, Code for the field approval of fuel-burning appliances and equipment . It supersedes the previous editions published in 2020, 2015, 2010, 2005, and 2000 by CSA Group (CSA) as CSA B149.3, and in 1989 by the Canadian Gas Association (CGA) as CAN/CGA-B149.3. This Code brings together for the convenience of users the applicable requirements for appliances and equipment, originally published as part of the CSA B149.1 and CSA B149.2 Codes. The major changes to this edition include the following: a) clarified the scope of the Code (Clauses 1.1 to 1.5); b) added hydrogen and hydrogen–natural gas blends to list of gases included in this Code (Clause 1.6); c) updated or added the following definitions: i) added definition for "fume incinerator" (Clause 3); ii) added definition for "installer" (Clause 3); iii) added definitions for "ovens" (Clause 3); iv) added definition for "operator" (Clause 3); v) added definition for "owner" (Clause 3); vi) updated "proven pilot" definition (Clause 3) vii) added definition for "process appliance" (Clause 3); viii) updated "protected inlet pressure" definition (Clause 3); ix) added definition for "safety control (or safety limit control) component" (Clause 3); x) added definition for "safety ventilation" (Clause 3); xi) updated "manual shut-off valve" definition (Clause 3); xii) added definition for "spring return valve" (Clause 3); and xiii) updated "valve train" definition (Clause 3); d) added multifunctional controls to pressure regulation requirements (Clause 4.6); e) added certification or monitoring requirements for pressure regulators (Clause 4.9); f) clarified requirements for manual isolation valves when two or more fuels are used in a dual or combination main burner (Clause 6.1); g) clarified requirements for manual and test firing valves visual indication of position (Clause 6.2); h) updated safety shut-off valve, vent valve, and VPS requirements (Clauses 8.1.12 to 8.1.23); i) clarified flame supervision requirements for main burners (Clauses 8.3.11 and 12.1.1); j) clarified installation, operation, and maintenance manuals requirements (Clauses 10.1.1 and 10.1.2 and Annex M); k) added appliance flue gas testing requirements (Clause 10.1.3); l) clarified requirements for pressure test point connection (Clause 10.3.3); m) clarification of the isolation of a vent line or an overpressure relief device (Clause 10.6.10); n) updated hose certification requirements (Clause 10.10); o) clarified requirements for intermediate relays (Clauses 12.1.3 and 12.1.4); p) clarified requirements for the isolation of a safety control, automatic vent valve, or overpressure protection device for maintenance and testing purposes (Clauses 10.6.10, 12.1.6, and 12.1.7); q) updated proven purge (Clauses 12.2); r) changed the requirement to have a low-fire start from 1 to 3.5 MMBtu/h (Clause 12.3); s) updated pilot gas low pressure safety requirements (Clauses 12.5.3); t) updated low gas pressure safety delay on start-up (Clause 12.5.4); u) updated air flow proving requirements (Clauses 8.3.7, 12.6, and 16.2.5); v) updated programmable controller requirements (Clauses 12.7.1 and 12.7.2.1 to 12.7.2.3); w) updated initial start-up requirements (Clause 15 and Annex A); x) added certification requirements for high-temperature limit controllers (Clause 16.5.4); y) added requirements for Class A ovens (Clause 16.10); z) updated requirements for hoses for compressors/pressure boosters (Clause 17.2.2); aa) updated Annex B for "Valve diagrams"; ab) updated Annex C for "Abbreviations"; ac) updated Annex E for "Guidelines for valve proving systems (VPS)"; ad) updated Annex J for "Mobile outdoor food service unit"; ae) added new Annex L for "Appliances and equipment for hazardous locations"; af) added new Annex M for "Recommended considerations for fired appliance installation, operation, and maintenance manuals"; and ag) added new Annex N for "Hydrogen or hydrogen – natural gas blends". CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of Natural Resources Canada. This Code was prepared by the Technical Committee on Field Approval of Fuel-Burning Appliances and Equipment, under the Fuels and Appliances Strategic Steering Committee, and has been formally approved by the Technical Committee and the Interprovincial/Territorial Gas Advisory Council. This Code has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. Scope 1.1 Inclusions This Code contains the requirements for fuel-burning appliances and equipment located downstream of the manual shut-off valve specified in Clause 6.18.2 of CSA B149.1. 1.2 Exclusions This Code does not apply to a) installations in marine pipeline terminals; b) gas where used as a feedstock in petroleum refineries or chemical plants; c) gas designated for storage or handling, or both, at propane gas bulk plants; d) gas where used for natural gas for vehicles; e) a new appliance that is certified to an approved Standard; f) a manually operated appliance with an input not exceeding 20 000 Btu/h (6 kW) used for industrial applications; g) other fuels not covered in this Code and used in combination with gas; and h) a certified appliance when changing the fuel type with a certified conversion kit for the appliance. 1.3 Application Requirements contained in this Code apply only to that portion of an appliance using gas as defined in Clause 1.6, atmosphere gas, and reaction gas. 1.4 Types of appliances and controls The requirements contained in this Code apply to a) an appliance that is not certified to an approved Standard; b) a previously certified or previously field-approved appliance where the certification or approval has been voided due to a modification of the appliance installation or control system; and c) programmable logic controllers or microprocessor-based controls used for flame safety and fuel-air ratio control. 1.5 Hierarchy For an appliance for which there is an approved standard, the requirements in this Code may replace or supplement the requirements in an approved standard to achieve a field approval under this Code, with the permission of the authority having jurisdiction (AHJ). 1.6 Gas type When the term "gas" is used, the requirements of this Code include, and apply equally to, any of the following gases or mixtures of them: natural gas, manufactured gas, propane, propane air, propylene, butane (normal butane or isobutane) butylene, hydrogen and hydrogen – natural gas blends. 1.7 Biogas When using biogas, this Code is to be used in conjunction with CSA/ANSI B149.6. 1.8 Units of measurement The values given in US customary units are the units of record for the purposes of this Code. The values given in parentheses are for information and comparison only. 1.9 Terminology In this Code, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Code; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Code. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.