Draft Details

Designation:ANSI Z21.78 • CSA 6.20
Contact name:Jennifer Hess
Review start date:Jun 4, 2024
Review end date:Aug 3, 2024
Contact email:thuy.ton(at)csagroup.org
Draft Scope/Description:

1.1 Inclusions

This Standard applies to newly produced combination gas controls (see Clause 3), hereinafter referred to as controls, constructed entirely of new, unused parts and materials.

1.2 Additional Inclusions

The combination control may include other functions such as pilot gas filters, pressure switches, etc., of an approved type (see Clause 3) or  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 in Clause 3), may be tested to ANSI Z21.21 • CSA 6.5 at the discretion of the manufacturer.

1.3 Exclusions

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.

1.4 Pressure ratings

This Standard applies to combination controls having a maximum operating gas pressure of 1/2 psi (3.5 kPa) with one or more of the following fuel gases: natural , propane, and hydrogen or hydrogen gas admixtures.

1.5 Temperature ratings

This Standard applies to combination controls which are capable of operation in ambient temperatures of 32°F (0 °C) to 125°F (51.5 °C), unless a higher temperature, lower temperature, or both, are specified by the manufacturer.

1.6 Additional Provisions for the United States

Clause 6 contains items unique to the United States.

1.7 Additional provisions for Canada

Clause 7 contains items unique to Canada.


1.9 Pressure references

All references to psi through this Standard  to be considered gauge pressure unless otherwise specified.

1.10 Terminology

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 designated normative (mandatory) or informative (non-mandatory) to define their application.

1.11 Units of measurement

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.

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