Figure 1-10.A typical boiler circuit.
When the water level is proved using the
try cocks, personnel should stand off to
the side of the try cocks away from the
discharge. The discharged hot steam or
very hot water can cause severe burns.
The gauge glass is located on the water column, as
shown in figure 1-6, item 3. The gauge glass allows the
boiler operator to see the water level in the boiler.
Normally there are two valves associated with the gauge
glass. One valve is located at the top and one is located at
the bottom of the gauge glass. These two valves, named
gauge cock valves (fig. 1-6, item 2). secure the boiler
water and steam from the gauge glass. Another valve (fig.
1-6, item 4) located in line with the gauge glass, is used to
blow the gauge glass down.
The SAFETY VALVE shown in figure 1-11 is the
most important of boiler fittings. It is designed to open
automatically to prevent pressure in the boiler from
increasing beyond the safe operating limit. The safety
valve is installed in a vertical position and attached
directly to the steam space of the boiler. The location can
be seen in figure 1-6, item 8. Each boiler has at least one
safety valve; when the boiler has more than 500 square
feet of heating surface, two or more valves are required.
Figure 1-11.A spring-loaded safety valve.