ANSI Z21.71-1993 (R2021)

Description

Preface This publication represents a basic standard for safe operation, substantial and durable construction, and acceptable performance for automatic intermittent pilot ignition systems for field installation. It is the result of years of experience in the utilization of gas, supplemented by extensive research. Nothing in this standard is to be considered in any way as indicating a measure of quality beyond compliance with the provisions it contains. It is designed to allow compliance of automatic intermittent pilot ignition systems for field installation, the construction and performance of which may exceed the various provisions specified herein. In its preparation, full recognition has been given to possibilities of improvement through ingenuity of design. As progress takes place, revisions may become necessary. When they are believed desirable, recommendations should be forwarded to the Chairman of Accredited Standards Committee Z21, 8501 East Pleasant Valley Road, Cleveland, Ohio 44131. Safe and satisfactory operation of an automatic intermittent pilot ignition system for field installation depends to a great extent upon its proper installation, and it should be installed in accordance with the National Fuel Gas Code, ANSI Z223.1, manufacturers’ installation instructions and local municipal codes. Users of this American National Standard are advised that the devices/products/activities within its scope may be subject to regulation at the Federal, state or local level. Users are strongly urged to investigate this possibility through appropriate channels. In the event of a conflict with this standard, the Federal, state or local regulation should be followed. Scope 1.1.1 This standard applies to the construction and installation procedures for newly produced automatic intermittent pilot ignition systems (see Part II, Definitions), hereinafter referred to as “systems”, constructed entirely of new, unused parts and materials and designed to be adapted to existing continuous pilot burners on listed forced air heating appliances and boilers equipped with atmospheric burners. 1.1.2 This standard does not apply to a system for use on appliances equipped with power burners or to direct vent appliances. 1.1.3 Systems covered by this standard shall be comprised of at least: (a) Pilot igniter(s) and cable(s); (b) Pilot flame sensor(s); (c) Associated system control; (d) Two automatic valves in series, controlling main burner gas; (e) Associated system wiring; and (f) Pressure regulator(s).