(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.
The maximum allowable working pressure on the shell or drum of a miniature boilershall be determined by the provisions of section 9-4-114 (1).
The factor of safety and the construction of miniature boilers, except where otherwise specified, shall conform to that required for power boilers.
Each miniature boiler shall be equipped with a spring-load, pop-type safety valve notless than one-half inch pipe size connected directly to the boiler.
The safety valve shall have sufficient capacity to discharge all the steam that can begenerated by the boiler without allowing the pressure to rise more than six percent above the maximum allowable working pressure.
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.
Each miniature boiler designed for operation with a definite water level shall beequipped with a glass water-gauge for determining the water level.
Miniature boilers operated in a closed system where there is insufficient space for theusual glass water-gauge may use water-level indicators of the glass bull's-eye type.
Every miniature boiler shall be provided with at least one water-feed pump or otherwater-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.
The water-feed pipe shall be provided with a check valve and a stop valve no less insize than that of the pipe.
Feed water shall not be introduced through the water column or gauge-glass connection while the boiler is under pressure.
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.
Each miniature boiler shall be provided with a blow-off connection, not less thanone-half inch iron pipe size, connected directly to the lowest water space.
Blow-off piping shall not be galvanized and shall be provided with a valve or cock.
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.
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.
For miniature boiler installations which are gas-fired, the burners shall conform tothe requirements of the American gas association and the A.S.M.E. boiler and pressure vessel code.
The heating element for electrically heated steam boilers, closed system, shall be soconstructed that the temperature will not exceed one thousand two hundred degrees Fahrenheit.
All miniature boilers heated with gas, oil, or electrical energy shall be provided withan automatic low-water fuel cutout and with an automatic fuel-regulating control, controlled by boiler pressure.
All cases not specifically covered by this article shall be treated as new installationsor may be referred to the director for instructions concerning the requirement.
Source: L. 71: R&RE, p. 281, § 1. C.R.S. 1963: § 17-3-16.