Okla. Admin. Code § 380:25-5-27

Current through Vol. 42, No. 6, December 2, 2024

Section 380:25-5-27 - Pressure/altitude gages, and pressure/temperature controls

(a) Each hot water boiler shall have a pressure or altitude gage connected to it or to its flow connection in such a manner that it cannot be shut off from the boiler except by a cock with a tee or lever handle placed on the pipe near the gage. The handle of the cock shall be parallel to the pipe in which it is located when the cock is open.

(b) The scale on the dial of the pressure or altitude gage shall be graduated approximately to not less than 1.5 nor more than 3 times the set pressure of the safety relief valve.

(c) Piping or tubing for pressure or altitude gage connections shall be of nonferrous metal when smaller than 1 inch pipe size.

(d) Each hot water boiler shall have a thermometer so located and connected that it shall be easily readable when observing the water pressure or altitude gage. The thermometer shall be so located that it will at all times indicate the temperature in degrees Fahrenheit of the water in the boiler at or near the outlet.

(e) Each automatically fired steam boiler shall be protected from over-pressure by two pressure-operated controls.

(1) Each individual automatically fired steam boiler shall have a safety limit control that will cut off the fuel supply to prevent steam pressure from exceeding the 15 psi maximum allowable working pressure of the boiler. Each control shall be constructed to prevent a pressure setting above 15 psi.

(2) Each individual steam boiler or each system of commonly connected steam boilers shall have a control that will cut off the fuel supply when the pressure reaches an operating limit, which shall be less that the maximum allowable pressure.

(3) Shutoff valves of any type shall not be placed in the steam pressure connection between the boiler and the controls described in (1) and (2) above. These controls shall be protected with a syphon or equivalent means of maintaining a water seal that will prevent steam from entering the control. The connections to the boiler shall not be less that 1/4 inch standard pipe size, but where steel or wrought iron pipe or tubing is used, they shall not be less than 1/2 inch standard pipe size. The minimum size of a syphon shall be 1/4 inch standard pipe size of 3/8 inch O.D. nonferrous tubing.

(f) Each automatically fired hot water boiler shall be protected from over-temperature by two temperature-operated controls. Each of these temperature controls shall be constructed to prevent a temperature setting above the allowable of 250 degrees F.

(1) Each individual automatically fired hot water boiler shall have a safety limit control that will cut off the fuel supply to prevent water temperature from exceeding the maximum allowable temperature of 250° F at the boiler outlet. In addition, the high limit temperature control shall be constructed to provide safety shutdown and lockout with manual reset when activated.

(2) Each individual hot water boiler or each system of commonly connected boilers without intervening valves shall have a control that will cut off the fuel supply when the water temperature reaches an operating limit, which shall be less than the maximum allowable temperature.

Okla. Admin. Code § 380:25-5-27

Amended at 16 Ok Reg 3017, eff 7-12-99