Section 12-222.1-9 - Electric and miniature boilers(a) In accordance with ASME BPVC Section 1, new miniature boilers shall be constructed, inspected, and bear the ASME certification mark with the 'S", "M", or "E" designator. The controls and safety devices shall be installed' in accordance with ASME CSD-1. New miniature boiler installations shall comply with section 12-222.1-5.(b) Miniature boilers used in generating steam for autoclave sterilizers shall be registered separately from the autoclave. The autoclave shall be registered as a pressure vessel if size and pressure is within limits unless exempted by section 12-220-2.1(c).(c) The maximum allowed working pressure is 100 psi in accordance with the ASME BPVC section 1.(d) Each miniature boiler shall be equipped with a sealed spring-loaded pop safety valve of not less than one-half (1/2) inch NPS.(e) Each steam line from a miniature boiler shall be provided with a steam rated stop valve located as close to the boiler shell or drum as is practicable, except when the boiler and steam receiver is operated as a closed system.(f) Miniature boilers for operation with a definite water level shall be equipped with a glass water gage for determining the water level. The lowest permissible water level for vertical boilers shall be at a point one-third (1/3) of the height of the shell above the bottom head or tube sheet. The following shall apply:(1) Tubular gage glasses on electric boilers shall be equipped with protective rods or shields; and(2) Each gage glass shall be fitted with a drain cock and valve having an unrestricted drain opening of not less than one-fourth (1/4) inch diameter to facilitate water flush draining of the gage glass.(g) Where the boiler is equipped with an internal furnace, the water level shall not be less than one-third (1/3) of the length of the tubes above the top of the furnace tube sheet.(h) In the case of small boilers operated in a closed system where there is insufficient space for the usual glass water gage, water level indicators of the glass bull's eye type may be used.(i) Miniature boilers shall be provided with at least one feed pump or other feeding device, except where it is connected to a water main carrying sufficient pressure to feed the boiler or where it is operated with no extraction of steam (closed system). In the latter case, in lieu of a feeding device, a suitable connection or opening shall be provided to fill the boiler when cold. Such connection shall be no less than one-half (1/2) inch NPS for iron or steel pipe and one-fourth (1/4) inch NPS for brass or copper pipe.(j) The feed pipe shall be provided with a check valve and a stop valve of a size not less than that of the pipe. The feedwater may be delivered through the blowoff opening if desired.(k) Miniature boilers shall be equipped with a blowoff connection, not less than one-half (1/2) inch NPS, located to drain from the lowest water space practicable. The blowoff piping shall be equipped with a stop valve not less than one-half (1/2) inch NPS.(l) Miniature boilers solely equipped with an automatic/timed blowoff valve shall be equipped with a manual bypass loop which bypasses automatic valve to facilitate testing of the low water cutoff controls.(m) Miniature boilers exceeding twelve (12) inches internal diameter or having more than ten (10) square feet of heating surface shall be fitted with not less than three (3) brass washout plugs of one-inch NPS which shall be screwed into openings in the shell near the bottom. In miniature boilers of the closed type system heated by removable internal electric heating elements, the openings for these elements, when suitable for cleaning purposes, may be substituted for washout openings.(n) Boilers not exceeding twelve (12) inches internal diameter and having less than ten (10) square feet of heating surface need not have more than two (2) one-inch openings for clean-outs, one of which may be used for the attachment of the blow-off valve. These openings shall be opposite to each other where possible. The following shall apply: (1) All threaded openings shall be opposite to each other where possible; and(2) All threaded openings in the boiler shall be provided with a riveted or welded reinforcement to give four (4) full threads therein.(o) Electric boilers of a design employing a removable top cover flange for inspection and cleaning need not be fitted with washout openings.(p) All valves, pipe fittings, and appliances connected to a miniature boiler shall be equal to at least the requirements of Class 125 or Class 150 of the appropriate ASME Standard as listed in ASME BPVC Section I.(q) All welded repairs and alterations to miniature boilers must comply with the rules in this part as defined in NBIC Part 3.Haw. Code R. § 12-222.1-9
[Eff and comp 12/21/2019] (Auth: HRS § 397-4) (Imp: HRS § 397-4)