CSA/ANSI B149.6:25

Preface This is the third edition of CSA/ANSI B149.6, Code for biogas generation and utilization. It supersedes the previous editions published in 2020 and 2015 under the title Code for digester gas, landfill gas, and biogas generation and utilization. The major changes to this edition include the following: a) restructured the format to amalgamate common requirements for each gas type and separate specific requirements for each type of gas system; b) harmonized the requirements for wastewater digester gas, organic digester gas, and landfill gas, where applicable, to avoid unnecessary repetition; c) added Clause 1.1.7 to clarify application of this Code for flares on biogas systems (Clause 1.1.7); d) added the definition for "biogas", which includes landfill gas, organic digester gas, and wastewater digester gas (Clause 3); e) added the definition for manual valves (Clause 3); f) added the definition for "control valve", "gas equipment room or building", "gas piping system", "isolation facility", "liquid seal", "liquid seal skirt", and "manual valve" (Clause 3); g) modified the definition for "compressor", "renewable natural gas", and "standby gas" (Clause 3); h) moved the flare valve train requirements from Annex D into the body of the Code (Clause 6.4); i) updated the clause relating to lubricated plug valves to align with recognized standards (Clause 8.8.4); j) updated the clause relating to manual valves to align with recognized standards (Clause 8.8.6); and k) added a new requirement for approved wiring diagrams for appliance control circuits (Clause 12.2). 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 Biogas Generation and Utilization, under the jurisdiction of the Strategic Steering Committee on Fuels and Appliances, and has been formally approved by the Technical Committee. This Code has also been formally approved by 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. This Code has been approved by the American National Standards Institute (ANSI) as an American National Standard. Scope 1.1 General 1.1.1 Biogas installation application This Code applies to the installation of systems for the production, handling, storage, and utilization of biogas in newly constructed facilities, as well as additions to and upgrading of existing systems. 1.1.2 Landfill demarcation This Code does not apply to any infrastructure of a landfill upstream of the main inlet valve on the vacuum side of the compressor or blower. 1.1.3 Biogas pressure limitations This Code applies to piping systems in which the maximum operating pressures for piping used in biogas systems do not exceed 860 kPag (125 psig) for piping installed outdoors or 450 kPag (65 psig) for piping installed indoors. 1.1.4 Biogas operation and maintenance application This Code applies to the safety aspects of the operation and maintenance for handling, storage, and utilization of biogas systems. Note: This Code does not apply to substrate storage, long-term digestate storage, or pilot scale and research digesters in biogas systems. 1.1.5 Hazard in biogas application This Code applies to existing biogas systems where, in the opinion of the authority having jurisdiction, a hazard or potential hazard exists. 1.1.6 Additional provisions Within the scope of Clauses 1.1.1 to 1.1.5, there might be provisions not covered in this Code, in which case the applicable provisions of the authority having jurisdiction are to apply. 1.1.7 Biogas flares and incinerators application This Code applies to the process gas stream or waste gas stream in relation to flares and incinerators within a biogas facility. For flare pilot systems utilizing propane or natural gas, see a) in Canada: CSA B149.3; and b) in the United States: API STD 537 for the field approval of fuel-burning appliances and equipment. 1.1.8 Exclusions Renewable natural gas is excluded from this Code. 1.2 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. 1.3 Dual dimensions The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.