370
��Popular Science Monthly
��A Low Water Alarm for Boilers, Which Has No Stuffing Boxes
��WHISTLE
���Sg-in.
��When the Water in the BoiUr Falls Below a Safe Level the Whistle Wii! Blow
T^HE low water alarm for steam boil-
J. ers shown in the illustration has no
packing boxes, the principal objection to
home-made alarms.
A whistle is connected with a globe valve. From the valve a piece of 'js-'m- iron pipe leads down. Locknuts hold the iron pipe and the boiler shell together at the top of the boiler.
To one end of a ])iece of rod 7/16-in. in diame- ter and 4 ins. long, a washer is attached and lo the other end a ball (globe) float. The^^-in. pipe and the 7/16-in. rod are held together by a ^S-in. check valve, which is turned upside down and the movable intericir disk is then remo\c(l. A pin is passed through the rod within the valve. This pin can be easily
��placed, as all upright checks unscrew to permit access to the inside.
Perhaps it would be a safer plan to omit attaching the globe valve as it might be closed accidentally or deliber- ately, by a careless attendant. When the water falls below a safe level the whistle will blow. — James E. Noble.
��A'
��Locomotive Runs Three Hours on Charge from Boiler Plant
FI RELESS steam locomotive is used for switching cars and tie trams at an Ohio manufacturing plant. The locomotive is of a t\'pe which was developed in Europe some years ago and is used around distillation plants, where cinders and live ashes would constitute a fire danger. It is operated by steam, the boiler being charged about seven times every twenty-four hours at the main boiler, at one hundred and fifty poimds pressure. The maintenance cost is \ery low. The tractive power is fully equal to that of the usual type, and .ilthough it weighs only twenty-two tons it has pulled as many as twelve loaded gondola cars at a time.
���This "Grease Ball" Was a Sticky, Insoluble Feed Water Deposit Formed in a Boiler
��A "Soap" Which Is Not Used for Cleansing
F(^RTY miles removed from the familiar grease product marketed as different varieties of soap is the "grease- ball" shown in the accompanying illus- tration. It was formed in a boiler as a deposit resulting from the precipitation of the carbonates of lime and magnesia in the feed water. When feed water enters a hot boiler the carbonates of lime and magnesia that the feed contains arc precipitated from so- lution and if the circula- tion in the boiler is not too active the precipita- ted matter often floats on or nc;u- the surface for a lime in light particles. When the floating car- lioiiaU's imite with the organic parts of any oil tiiat may be in the boiler the soap is formed.
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