1.1 Scope 1.1.1 This standard applies to newly produced combination gas controls (see
Definitions, Part IV), hereinafter referred to as controls, constructed
entirely of new, unused parts and materials. 1.1.2 The combination control may include other functions such as pilot gas
filters, pressure switches, etc., which shall be of an approved type (see
Definitions, Part IV), or shall be investigated as an integral part of the
combination control for construction and performance equivalent to an approved
type. A control which incorporates two or more automatic valves and no other
function, (as defined by combination control, see Definitions, Part IV), may be
tested to this standard or Z21.21-CGA 6.5, automatic gas valve standard, at
the discretion of the manufacturer. 1.1.3 Compliance of a combination control with this standard does not imply
that the combination control is acceptable for use on gas appliances without
supplemental tests with the combination control applied to the particular
appliance design. 1.1.4 This standard applies to combination controls having a maximum operating
gas pressure of ½ psi (3.45 kPa) with one or more of the following fuel gases:
natural, manufactured, mixed, liquefied petroleum and liquefied petroleum
gas-air mixtures. 1.1.5 This standard applies to combination controls which are capable of
operation in ambient temperatures of 32°F (O°C) to 125°F (51.5°C), unless a
higher temperature, lower temperature or both, are specified by the
manufacturer. 1.1.6 Exhibit A contains items unique to the U.S. 1.1.7 Exhibit B contains items unique to Canada. 1.1.8 Exhibit C contains a list of standards specifically referenced in this
standard, and sources from which these reference standards may be obtained. 1.1.9 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. 1.1.10 All references to psi through this standard are to be considered gage
pressure unless other specified.