(1)Miniature boilers shall
be installed in accordance with the provisions in section 9-4-113 unless a special
exemption is stated in this article or otherwise provided by the director.
(2)The maximum allowable working pressure on the shell or drum of a
miniature boiler shall be determined by the provisions of section 9-4-114 (1).
(3)The factor of safety and the construction of miniature boilers, except
where otherwise specified, shall conform to that required for power boilers.
(4)Each miniature boiler shall be equipped with a spring-load, pop-type
safety valve not less than one-half inch pipe size connected directly to the boiler.
(5)The safety valve shall have sufficient capacity to discharge all the steam
that can be generated by the boiler without allowing the pressure t
Free access — add to your briefcase to read the full text and ask questions with AI
(1) Miniature boilers shall
be installed in accordance with the provisions in section 9-4-113 unless a special
exemption is stated in this article or otherwise provided by the director.
(2) The maximum allowable working pressure on the shell or drum of a
miniature boiler shall be determined by the provisions of section 9-4-114 (1).
(3) The factor of safety and the construction of miniature boilers, except
where otherwise specified, shall conform to that required for power boilers.
(4) Each miniature boiler shall be equipped with a spring-load, pop-type
safety valve not less than one-half inch pipe size connected directly to the boiler.
(5) The safety valve shall have sufficient capacity to discharge all the steam
that can be generated by the boiler without allowing the pressure to rise more than
six percent above the maximum allowable working pressure.
(6) In cases where the miniature boiler is supplied with feed water directly
from a pressure main or system without the use of a mechanical feeding device, the
safety valve shall be set to release at a pressure not in excess of ninety-four
percent of the lowest pressure obtained in the supply main or system feeding the
boiler. Return traps shall not be considered mechanical feeding devices.
(7) Each miniature boiler designed for operation with a definite water level
shall be equipped with a glass water-gauge for determining the water level.
(8) Miniature boilers operated in a closed system where there is insufficient
space for the usual glass water-gauge may use water-level indicators of the glass
bull's-eye type.
(9) Every miniature boiler shall be provided with at least one water-feed
pump or other water-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, such system being commonly known as a closed system.
(10) The water-feed pipe shall be provided with a check valve and a stop
valve no less in size than that of the pipe.
(11) Feed water shall not be introduced through the water column or gauge-glass connection while the boiler is under pressure.
(12) Pressure of a feed water system greater than the maximum allowable
working pressure of the boiler shall be fitted with a pressure-reducing valve before
feed water is introduced into the boiler.
(13) Each miniature boiler shall be provided with a blow-off connection, not
less than one-half inch iron pipe size, connected directly to the lowest water space.
(14) Blow-off piping shall not be galvanized and shall be provided with a
valve or cock.
(15) Each miniature boiler shall be equipped with a steam-gauge having its
dial graduated to not less than one and one-half times the maximum allowable
working pressure. The gauge shall be connected to the steam space or to a steam
connection to the water column. The gauge or connection shall contain a siphon or
equivalent device which will develop and maintain a water seal that will prevent
steam from entering the gauge tube. The minimum size of a siphon, if used, shall be
one-fourth inch inside diameter.
(16) The steam piping from a miniature boiler shall be provided with a stop
valve located as close to the boiler shell or drum as is practicable, except where the
boiler and steam receiver are operated as a closed system.
(17) For miniature boiler installations which are gas-fired, the burners shall
conform to the requirements of the American gas association and the A.S.M.E.
boiler and pressure vessel code.
(18) The heating element for electrically heated steam boilers, closed
system, shall be so constructed that the temperature will not exceed one thousand
two hundred degrees Fahrenheit.
(19) All miniature boilers heated with gas, oil, or electrical energy shall be
provided with an automatic low-water fuel cutout and with an automatic fuel-regulating control, controlled by boiler pressure.
(20) All cases not specifically covered by this article shall be treated as new
installations or may be referred to the director for instructions concerning the
requirement.