Specifies the requirements and test methods for the construction, safety, classification and marking of non-domestic gas-fired overhead radiant tube heaters incorporated into a multi-burner system with each burner unit under the control of an automatic burner control system. Applicable to Type B[22x] and Type B[23x] systems intended for use in other than domestic dwelling, in which the supply of combustion air and/or evacuation of the products of combustion is achieved by mechanical means. Applicable to systems which are intended to be type tested.