Gas appliance pressure regulators
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This is the fourth edition of CSA/ANSI Z21.18 • CSA 6.3, Gas appliance pressure regulators. It supersedes the previous editions published in 2007, 2000, and 1995.
This Standard 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 Standard has been approved by the American National Standards Institute (ANSI) as an American National Standard.
This Standard applies to individual gas appliance pressure regulators, which are not a part of a combination control (see Clause 3, Definitions), constructed entirely of new, unused parts and materials, hereinafter referred to as regulators, intended for application on individual gas appliances.
This Standard also applies to negative gas appliance pressure regulators (see Clause 3, Definitions). The performance of negative pressure regulators is covered under Clause 6 of this Standard.
Compliance of a device with this Standard does not imply that such device is acceptable for use on gas appliances without supplemental tests with the device applied to the particular appliance design.
Components performing functions other than those of a gas appliance pressure regulator comply with the applicable American National Standards.
This Standard applies to regulators for operations with natural, manufactured and mixed gases, liquefied petroleum gases, and LP gas-air mixtures.
This standard applies to regulators classified in accordance with their intended application with reference to inlet pressures as follows:
Rated inlet pressure:
1/2 psi | (3.5kPa)
2 psi | (13.8 kPa)
5 psi | (34.5 kPa)
This Standard applies to regulators for the following general types of application:
a) main burner load application;
b) pilot burner load application;
c) main burner and pilot burner load application to control a minimum pilot flow rate of:
i) 0.15 ft3/hr (1.18 cm3/s); or
ii) 0.50 ft3/hr (3.93 cm3/s); or
d) domestic range application (see Clause 5.11, Regulators for use on domestic gas ranges).
If a value for measurement as given in this Standard is followed by an equivalent value in other units, the first stated value is to be regarded as the specification.
All references to “psi” throughout this Standard are to be considered gauge pressures unless otherwise specified.
Clause 8, Items Unique to the Canada, contains provisions that are unique to Canada.
Clause 2, Reference publications, contains a list of standards specifically referenced in this Standard.
In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; “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 Standard.
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 designed normative (mandatory) or informative (non-mandatory) to define their application.