Packaged high pressure boilers

means a packaged boiler that is:

(4) A steam boiler designed to operate at a steam pressure higher than 15 psi gauge (psig);

(5) A hot water boiler designed to operate at a water pressure above 160 psig or at a water temperature exceeding 250°F, or both; or

(6) A boiler that is designed to be capable of supplying either steam or hot water, and designed to operate under the conditions in paragraphs (1) and (2) of this definition.