Section 408.4242. Pressure gauges.

Rule 242. (1) Each steam boiler shall have a pressure gauge, with  dial range not less than 1 1/2 times the maximum allowable working  pressure, connected to the steam space or to  the  steam connection   to   the   water column.

(2)   The pressure gauge shall be connected to a siphon or equivalent device of sufficient capacity to keep the gauge tube filled with water and so arranged that the gauge cannot be shut off from the boiler except by a cock placed near the gauge and provided  with  a   tee   or    lever   handle arranged to be parallel to the pipe in which it is located when  the  cock is open.

(3)   When  a  pressure  gauge  connection  longer  than   8    feet   becomes necessary, a shutoff valve may be used near the boiler provided the valve is of the outside-screw- and-yoke type and is locked open. The line shall be of ample size with provision for free blowing.

(4)   Each boiler shall be provided with a 1/4-inch nipple and globe  valve connected to the steam space for the exclusive purpose of attaching a  test gauge when the boiler is in service so that the accuracy  of  the   boiler pressure gauge may be ascertained.

(5)   The scale on the dial of a steam heating boiler shall be graduated to not less than 30 psi. The travel of the pointer from 0 to 30 psi shall be at least 3 inches.

History: 1979 AC.