Maximum allowable working pressure for nonstandard boilers

Nonstandard miniature boilers: 1. Must conform to all requirements of this chapter. 2. Must have a factor of safety as given in subsection 5 of section 33.1-14-05-02. 3. Must be given an initial inspection that must include a hydrostatic pressure test. 4. May not have solder or silver solder as a method of attachment of any pressure part of the entire assembled unit. 5. May have a plate for the North Dakota stamp and registration number to be welded to boiler proper. The plate must be placed in a conspicuous and accessible location with a minimum size thickness of one-sixteenth inch [1.59 millimeters], length two inches [50.8 millimeters], and width one inch [25.4 millimeters]. 6. May not exceed the design criteria limits as defined in subsection 20 of section 33.1-14-01-01. 7. Of the watertube, fired-coil and fired-radiator design must be considered as not meeting the requirements of this section. 8. Exceeding twelve inches [304.80 millimeters] internal diameter must have at least one, one inch [25.4 millimeter] opening in the bottom of the shell and one, one inch [25.4 millimeter] opening in each water leg. Boilers not exceeding twelve inches [304.80 millimeters] internal diameter must have one-half inch [12.7 millimeter] opening in the shell and one-half inch [12.7 millimeter] opening in each water leg. 9. Construction material used for fabrication of the shell must be steel of at least fifty-five thousand pounds per square inch [386.11 megapascals] tensile strength. Material of tubes may be steel, brass, or copper with a rating equal to materials from section 2 of the American Society of Mechanical Engineers Code.