Improvements in Water-gauges.
Year: 1890

page_text: Date of Application, 25th Nov., 1890
Complete Specification Left, 26th June, 1891-Accepted, 1st Aug., 1891
PROVISIONAL SPECIFICATION.
Improvements in Water-gauges.
We, JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the firm of
J. Hopkinson & Co., of Huddersfield, in the County of York, Engineers, do hereby
declare the nature of this invention to be as follows:-
Our invention relates to water gauges of the kind or class in which an uncon-
trolled automatic valve is employed to shut off the water in case the gauge glass
breaks.
In such water-gauges as heretofore constructed there is great risk under some
circumstances of the valve being held to its seat by the preponderance of pressure
in the lower arm due to the column of water in the boiler over and above that in
the upper or steam arm, and should the valve be forced to its seat when the gauge
glass is empty of water it is obvious that in such circumstances the pressure due to
the column of water acts to keep the valve against its seat and therefore the gauge
gives an erroneous indication of the water level in the boiler. This condition can
exist while the steam and water cocks are open.
Now the object of our present invention is to construct a water gauge so arranged
in respect of its automatic valve, that the weight of the said valve in relation to the
area of the orifice or seat on which the valve or ball closes the connection between
the gauge arm and the glass, and to the column of water in the boiler, shall be such
that if the valve or ball is thrown to its seat from any cause while the glass
is intact and empty of water it will not remain in that position but will drop from
its seat thus automatically restoring the connection between the boiler and the
glass, through the lower or water arm.
'
We prefer to construct the water gauges embodying our present invention
substantially as described in the Specification of our Patent No. 1435: dated
27 January 1890 in respect of the inclined floor or surface on which the valve or
ball rests and the manner of introducing and removing the same through the front
or side of the gauge. We, in some instances, dispense with the guides referred to
in the said Specification. And in some instances we construct the water-gauge so
that we can insert and remove the valve through the bottom of the gauge-arm.
For this purpose we construct the try-cock with an extension to form the floor for
the said valve: Or we screw into its gauge-arm a suitable floor for the said valve
to rest upon.
In all cases the construction and arrangement must be such as will
allow free and uninterrupted communication between the glass, the gauge-arm and
the try-cock.
Dated this 25th day of November 1890
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Water-gauges;
We, JOHN ADDY HOPKINSON and JOSEPH HOPKINSON, both of the firm of
J. Hopkinson & Co. of Huddersfield in the County of York, Engineers 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:
Ox invention
olates
water
R of the kind or class in which an

page_text: uncontrolled automatic valve is employed to shut off the water in case the gauge
glass breaks.
In such water gauges the automatic valve should be so arranged that it can never
under the circumstances or conditions hereinafter set forth by preventing com-
munication between the boiler and the interior of the gauge-glass give a false
or incorrect indication of the water level in the boiler. But in automatic water-
gauges as heretofore constructed there is an element of danger arising from the
possibility that under some circumstances the valve will cut off communication
between the boiler and the gauge-glass at a time when free communication between
them is essential to the proper action of the gauge.
This danger arises from a preponderance of pressure in the lower or water arm
over and above that in the upper or steam arm, such preponderance being due to
the head of water in the boiler above the level of the water arm.
Should the valve be forced against its seat when the gauge-glass is empty
of water it is obvious that in such circumstances the pressure due to the aforesaid
head of water will operate as a force tending to keep the valve against its seat, and
if the weight of the valve is insufficient to overcome the force or pressure tending
to keep it up the said valve will be retained against its seat and the water passage
leading to the gauge-glass will therefore remain closed. Under these circum-
stances a false indication will be given by the gauge. The valve once forced
against its seat will be retained in that position until condensation of steam
has taken place in the gauge-glass to such a degree that the weight of the
condensed steam together with the weight of the valve will be equal to the upward
pressure acting on the valve and tending to keep it closed. In some instances
however, especially where the water is bad or dirty the valve having been forced
against its seat if allowed to remain may be caused to adhere thereto. In such
cases the valve will not drop even when the equilibrium of pressure above and
below the valve is restored and the condensation of steam in the gauge-glass
will go on until a higher level is shown in the glass than really exists in the
boiler. It will thus be seen that a false indication of water level either above or
below the true level may be given by the gauge. This condition of things may
exist while the steam and water cocks are open.
The object of our present invention is to construct a water gauge so arranged in
respect of its automatic valve that the weight of the said valve in relation to the
maximum pressure tending to keep the valve closed shall be such that if the valve
is thrown to its seat from any cause while the gauge glass is intact and empty
or partially empty of water it will not remain in that position but will immediately
drop from its seat and will thus automatically restore the connection between the
water arm and the gauge glass.
The pressure tending to keep the valve to its seat is chiefly due to the
preponderating column of water. By the preponderating column of water we mean
a column having a length equal to the head of water in the boiler above the level
of the valve and an area equal to that of the valve seat.
We prefer to construct the water gauges embodying our present invention
substantially as described in the Specifications of our Patents No. 1435 dated
January 27th 1890 and No. 6141 dated April 22nd 1890 in respect of the inclined
floor or surface on which the valve or ball rests and the manner of introducing and
removing the same through the front or side of the gauge. We in some instances
dispense with the guides referred to in the said Specification. And in some
instances we construct the water-gauge so that we can insert and remove the valve
through the bottom of the gauge arm. For this purpose we construct the try-cock
with an extension to form the floor for the said valve. In all cases the construction
and arrangement must be such as will allow free and uninterrupted communication
between the glass, the gauge arm and the try-cock.
An advantage arising from our invention is that the valve being much heavier
than in gauges heretofore constructed there is less liability of the same adhering to
its seat by reason of dirty or bad water.

page_text: We wish it clearly understood that we do not limit ourselves to any precise or
particular ratio or proportion of the diameter of the ball to the area of the tube or
column of water. It is the weight of the ball relatively to the pressure due to
the preponderating column of water that we have to ascertain and determine.
That is to say. Whatever may be the height or weight of such column, or the
area of the tube and seat aperture the ball must, according to our invention, be of
such a weight as to overcome the maximum pressure tending to keep it to its seat,
except when the glass is broken, as above set forth.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
A water gauge in which there is an automatic valve the weight of which
relatively to the pressure tending to keep the valve to its seat is such as herein
described for the purpose specified.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicants.