Lunkenheimer Water Gauge.
BLOW OFF VALVE.
The Blow Off Valve is an angle or globe valve attached to the lower part of a boiler for the purpose of blowing off the sediment accumulated by the use of impure water, and should be used more or less frequently according to the condition of the water used, but never less than once a week. There is also a surface blow off which is attached to the boiler at about the safe water level for the purpose of blowing off the scum which accumulates on top of the water. This scum should be blown off once or twice a day.
GAUGE COCK.
A Gauge Cock is a stop cock attached to a boiler to ascertain the height of water in the boiler. There are generally two and sometimes three gauge cocks attached to a boiler. The lower one enters the boiler as low down as it is deemed safe to allow the water to get, while the upper one enters the boiler sufficiently high to avoid getting too much water. Where three gauges are used, the middle one enters the boiler at about the proper water level. They should be opened frequently to keep them free from corrosion, being sure to close them tightly to prevent leaking.
Lunkenheimer Gauge Cock.