Nevada Administrative Code
Chapter 455C - Boilers, Elevators and Pressure Vessels
BOILERS AND PRESSURE VESSELS
Boilers
Section 455C.262 - Steam gauges

1. Each steam boiler must have a steam gauge connected to the steam space or to the steam connection to the water column. The steam gauge must have a dial range that is graduated to approximately double the pressure at which the safety valve is set, but in no case to less than 1 1/2 times this pressure. The steam gauge must be connected to a siphon or equivalent device of sufficient capacity to keep the gauge tube filled with water and arranged so 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.

2. If a steam gauge connection which is longer than 8 feet is necessary, a shutoff valve may be used near the boiler if the valve is of the outside-screw-and-yoke type and is locked open. The line must be of ample size with provision for free blowing. Each boiler must 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 steam gauge may be determined.