Never allow the gauge cocks to leak at all when it is practicable to repair them, for the longer they leak the more difficult they are to repair, as under the escape of water or steam the metal wastes rapidly.
An engineer or fireman should often remove the ashes from under the boiler, or from ash pan; if allowed to accumulate, they retard the draft and interfere with combustion, thereby causing waste of fuel and interfere with the evaporating efficiency of the boiler. Also keep grates clear of clinkers; for if allowed to accumulate, they produce the same result.
Should it become necessary to blow down the water at intervals, the engineer or fireman should stand by the blow-off cock and not allow his attention to be diverted to anything else, as in a very short space of time the water may become so low as to induce stoppage or endanger the safety of the boiler.
Engineers should always be cautious when they stop or start an engine with a heavy pressure of steam in the boiler, as the vent given to the steam when starting, and the check it receives when stopping, may exert such a pressure as to strain, crack, or rupture the boiler.
The drip cocks in the cylinder should be left open when the engine is standing still, and they should not be closed until after the engine has been started and made several strokes or revolutions.
Do not open the throttle valve to its full extent in starting after the engine has been standing over night, as the quantity of steam condensed by being brought in contact with the cold pipe (particularly if it is a long one) may result in breaking the follower plate, springing the piston rod, or knocking out the cylinder head.
After opening the gauge cocks to ascertain the height of water in the boiler, they should be closed tightly to prevent leakage.
It may have been discovered that when gauge cocks are closed after being blown out, they leak badly; this is often due to the fact that mud or sand has become attached to the seat of the valve. The easiest way to remedy this difficulty is to open the cocks and let them blow out for some time, as the friction of the water in its escape will in all probability remove the obstacle.
Glass water gauges may be cleansed by removing the glass; then tying a piece of cotton waste or lamp wicking to a splint of wood, applying soap or acetic acid, and passing it through the inside of the tube; then replace the glass, and when steam is raised close the lower valve, open the drip cock, and the steam blowing through will wash the glass perfectly.
To cut a glass gauge tube.—If a glass gauge is too long, take a three-cornered file and wet it, hold the tube in the left hand with the thumb and fore-finger at the place where you wish to cut, saw it quickly and lightly two or three times with the edge of the file, and it will mark the glass. Now, take the tube in both hands, both thumbs being on opposite sides of the mark and about an inch apart, then try to bend the glass, using your thumbs as fulcrums and it will break at the mark which has weakened the tube.