IMPROVEMENTS IN LOW WATER ALARMS FOR STEAM BOILERS
Year: 1885

page_text: I, HUDSON WILSON, of No 1, Filey Street, Bradford in the County of York,
Engineer, do hereby declare the nature of my invention for "IMPROVEMENTS IN
LOW WATER ALARMS FOR STEAM BOILERS," to be as follows:-
My invention relates to certain improvements in low water alarms, and has for
its object the arrangement of the apparatus in such a manner, that the alarm valve
is kept clear of grit or other impurities whenever it. is opened in consequence of
the water in the boiler getting below the desired level, which I accomplish in the
following manner :-
The apparatus may be fixed to the top or in front of steam boilers, and consists
in securing to a base block, columns that support a bridge casting, and of screwing
into the said base a pipe which extends to below the usual or working level of the
water, This pipe communicates with another of enlarged diameter having a solid
end, and immediately above the same within the before mentioned bridge casting,
is an adjustable box containing a valve which is supplied with steam from the
crown of the boiler.
When the water in the boiler is below the working line, the expanded pipe
empties itself of water and is filled with steam, which expands the same and causes
it to come in contact with the valve spindle immediately (above, thereby opening
the valve which allows steam to escape. into the box to which is attached an
ordinary steam whistle.

page_text: I, HUDSON WILSON of No 1 Filey Street, Bradford, in the County of York,
Engineer do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The object of my invention is the arrangement of the apparatus in such a
manner that the alarm valve is kept clear of grit or other impurities whenever it
is opened in consequence of the water in the boiler getting below the required level,
which I accomplish in the following manner.
My improved apparatus may be fixed to the top or in front of steam boilers, and
consists in securing to a base block columns that support a bridge casting, and of
screwing into the said base block an internal pipe which extends to below the
usual or working level of the water in the boiler. This pipe communicates with
another of enlarged diameter having a solid end at the top, and immediately above
the same may be placed a box containing a valve which is supplied with steam
from the crown of the boiler.
When the level of the water is below the end of the internal pipe, it empties
itself and becomes charged with steam, which causes the pipe to expand and come
in contact with the valve spindle immediately above, thereby opening the valve
and thus allowing the steam to escape through a small pipe from the boiler to an
ordinary whistle, or by the expansion of the said pipe to raise the lever or levers
of an ordinary safety valve.
In order to make my invention better understood, I will further describe the
same by making reference to the accompanying drawings in which Fig. 1 represents
a side elevation of my improved apparatus shewn in combination with an ordinary
safety valve, Fig. 2 is a front view of the same partly in section, Fig. 3 a side
view of my apparatus combined with a spring safety valve, the lever and tongue
connections to the valve being of the ordinary construction, and Fig. 4 is a sectional
detail through the before mentioned box.
To the top of the boiler I fix a base block A, to which is secured two columns BB
for supporting the bridge casting C through the centre of which the pipe D made
of brass or other well known alloy is free to pass. The said pipe also extends for a
short distance inside the boiler, and to the end of which is attached a pipe E of
such length that the bottom end thereof is below the usual working level of the
water. The top end of the pipe D is solid and free to expand through the bridge
casting C, the solid end D¹, when the pipe is in its normal condition, being in close
proximity to the end of the valve spindle F.
To the upper part of the bridge casting C I attach by the nuts N the box G
jointed by the flanges near the centre and which is connected by pipe J to the
crown of the boiler for supplying steam to the valve F¹ and whistle K when the
valve is operated in the manner as hereinafter described.
The water is forced up the pipe E and central pipe D by the pressure in the
boiler, and having no circulation therein the water in the pipe D is comparatively
cool with that in the boiler, but directly the water in the boiler gets below the end

page_text: of the internal pipe E, they become empty and charged with steam which warms
and thereby causes the pipe D to expand, the solid end at D¹ coming in contact
with the end of the valve spindle F, thereby raising the valve by which steam is
allowed to escape through pipe J to the whistle K, thus giving an audible alarm
as to the condition of the water level in the boiler.
When the expansion pipe D is combined with a safety valve, I form the valve
lever M with an opening through as shewn by Fig. 5, the pipe D passing through
the same as shewn, and screw the nuts L on the tube D at such a distance from
the said lever M, that when the pipe D is expanded in the manner as before
described, the top nut will come in contact with the said lever and raise the same,
thus allowing steam to escape from the boiler, thereby indicating that the water is
below its usual working level, the steam continuing to escape until the water is
again above the bottom of the internal pipe E.
The expansion pipe D may be used without the whistle attachment for detecting
the low water in boilers by the arrangement shewn by Figs. 6 and 7 which
represent the expansion tube D fitted at the top with a cross bar K¹ to which are
attached two links P and P¹ secured to the said bar by nuts N¹ and having at the
other end of each a slot hole through which the respective levers of an ordinary
double safety valve pass and are raised by the expansion of the tube D in the
manner as before described thereby allowing steam to escape from the valves V
whenever the water level is below the end of the internal pipe E and thus draw
the attendant's attention to the level or condition of the water in the boiler.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
The combination of the parts of low water alarms in the manner shewn and
described by which the boiler attendant's attention is directed to the water level
in the boiler by the sounding of a whistle or the escape of steam through the safety.
valve whenever the water is below a determined level in the boiler.