ANSI Z21.78A-1998/CGA 6.20A-M98

Scope

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.