Apparatus and Appliances for Steam Boilers.
Year: 1886

page_text: Date of Application, 16th Mar., 1886.
Complete Left, 15th Dec., 1886.
Complete Accepted, 18th Jan., 1887.
Apparatus and Appliances for Steam Boilers.
I JOHN HENRY DEWHURST of Meersbrook Edge, Sheffield in the County of
York, Mechanical Engineer, do hereby declare the nature of my said Invention for
IMPROVEMENTS IN LOW WATER AND HIGH PRESSURE STEAM ALARM APPARATUS AND
APPLIANCES FOR STEAM BOILERS" to be as follows:-
This Invention is an improvement upon my Low Water alarm Apparatus for
Steam Boilers Patented A.D., 1884, and numbered 6802.
The Apparatus therein described, although answering the purpose for which it was
Invented namely, to automatically sound an alarm whistle when the water in the
Boiler got below the prescribed safe working level, I found in practice that it was
necessary for an Attendant to close the alarm valve (E), when it once had been opened,
as the blow through did not cease when the water level in the Boiler was raised so as
to cover the orifice of the expanding pipe or Tube D, for, on the water rising within
the orifice last named, the pressure of steam in the Boiler caused a flow of hot water to
be blown through the tube D, and out through the Alarm Valve and whistle Orifices into
the open Air. The Tube D, by reason of this continuous flow of hot water being kept
hot remained in its expanded condition, thus keeping the Alarm Valve open; on the
attendant closing the valve the water within the tube D, having ceased to flow or circulate
soon became cooled by the action of the atmosphere, upon which the Tube D, contracted
to its normal length, and ceased to act upon the valve.
The primary object of my present Invention is to obviate this defect, by making the
Apparatus Automatic in the closing, as well as in the opening of the Alarm Valve, and I'
effect this object in the following manner; in lieu of the steam, required to sound the
alarm, being conducted through the expansion Tube D; by my improved arrangement
I convey the steam through a supplementary pipe or pipes to the back of the Alarm
Valve, the opening or openings to the separate pipe or pipes last named being placed in
the steam space high above the water level in the Boiler, so that, when the alarm valve
is opened by the expansion of the pipe D; dry, or comparatively dry steam is allowed
to pass through the valve and to sound the Alarm Whistle. The expanding pipe D,
may be entirely closed at its upper or outer end.

page_text: By the improved Arrangement herein last described, after the alarm Valve has been
opened, it would remain open until the level of the water in the Boiler had been raised
so as to cover the orifice at the lower end of the said Tube D, the pressure of the steam
in the boiler would then cause the water to rise within the Tube D, where, in the
absence of circulation it would speedily become cooled by the action of the Atmosphere,
when it would contract to its normal length, and, the alarm valve would be at once
closed by the steam pressure at its back. The alarm whistle may be placed either
under the valve concentric with the valve spindle," or, it may be placed vertically on
the valve case.
Although the object of my present Invention may be effected by the employment of
one or more supplementary steam pipes, I should by preference employ two such
pipes, both of which may be connected at their lower extremities to the cap A, which
is fixed to the Boiler, their upper extremities may be fixed to the aların valve case, or
branches therefrom, corresponding to two branches which may be provided in the
cap A, thus, the two Auxiliary steam pipes would form standards or supports for the
valve case.
The valve case may be fitted with a screw cap through which the valve may be
examined, removed, or ground on its seat; the expanding pipe D, may be closed by a
screwed cap to close its upper or outer end, and this cap may be fitted with a set-screw
and lock nut by which the distance between the end of the valve spindle and the end of
the expanding pipe D may be adjusted to the greatest nicety.
A small screw valve may be fitted in the cap A, so that, in the event of it being
found desirable to test the action of the apparatus; by means of this valve the steam
may be allowed to pass from the Auxiliary steam pipes or passages into the expanding
pipe D, or passage leading thereto, by which the equilibrium of pressure in all the pipes
would be restored, the water in the expansion pipe D, would then fall to the level of
the water in the Boiler, and the steam having filled the pipe D, would cause it to
expand and, thereby open the alarm Valve and sound the Whistle, and, in fact produce
the same result as if the Boiler had become short of water.
The improvements and modifications herein described do not affect the essential
features of my previous invention, which, in so far as the general principle and action,
and, the materials employed in its construction is concerned, is applicable in either
case.
The secondary object of my present Invention is to combine with the low water
alarm apparatus herein described a high pressure steam alarm which I effect by
attaching a valve and whistle in a convenient position either on the low water alarm
valve case (on the steam side of the valve) or on a branch or branches connected
therewith or to one or both of the supplementary steam pipes herein before referred
to, such valve being loaded either by a dead weight or spring and adjusted to the
required pressure, the action of the valve being the same as a safety valve which
would rise and open when the steam in the boiler exceeded the maximum pressure and
the escaping steam would sound the alarm whistle which might be better heard at a
distance or under other circumstances than the noise made by the blowing off of steam
through the ordinary safety valve or valves of the steam Boiler The high pressure
steam whistle may be made to sound a different note to that produced by the low
water alarm so that the attendant or other persons might know the cause for which the
alarm was raised.

page_text: W
Apparatus and Appliances for Steam Boilers.
1 JOHN HENRY DEWHURST, of Meersbrook Edge, Sheffield, in the County of York,
Mechanical Engineer, do hereby declare the nature of my said Invention for
"IMPROVEMENTS IN LOW WATER, AND HIGH PRESSURE STEAM ALARM, APPARATUS AND
APPLIANCES FOR STEAM BOILERS," and in what manner the same is to be performed, to
be particularly described, and ascertained, in and by the following statement :-
This Invention is an improvement upon my Low Water alarm apparatus for Steam
Boilers, Patented, A.D. 1884, and numbered 6802.
The apparatus therein described although answering the purpose for which it was
invented namely, to automatically sound an alarm whistle; when the water in the
boiler got below the prescribed safe working level, I found in practice that it was
necessary for an attendant to close the alarin valve, (E), when it once had been
opened, as the blow through, did not cease when the water level in the Boiler was raised
so as to cover the orifice leading to the expanding pipe or Tube (D) for on the water
rising within the orifice last named, the pressure of steam in the boiler caused a flow of
hot water to be blown through the tube D, and out through the alarm valve and
whistle orifices into the open Air, The Tube D by reason of this continuous flow of
hot water being kept hot, remained in its expanded condition, thus keeping the
alarm valve open; on the attendant closing the valve the water within the tube D, having
ceased to flow or circulate, soon became cooled by the action of the atmosphere, upon
which it (the tube D) contracted to its normal length, and ceased to act upon the
valve.
The primary object of my present Invention is to obviate this defect, by making the
apparatus automatic in the closing, as well as in the opening of the alarm Valve, and I
effect this object in the following manner; in lieu of the steam (required to sound the
alarm), being conducted through the expansion Tube D, by my improved arrangement,
I convey the steam through a supplementary pipe or pipes to the back of the alarm
Valve, the opening or openings to the separate pipe or pipes last named being placed in
the steam space high above the water level in the boiler, so that, when the alarm valve
is opened by the expansion of the pipe D; dry or comparatively dry steam is allowed
to pass through the Valve and to sound the alarm whistle; The expanding pipe D,
may be entirely closed at its upper or outer end.
By the improved arrangement herein last described, after the alarm valve has been
opened, it would remain open until the level of the water in the Boiler had been raised
so as to cover the orifice leading to the lower end of the said Tube D, the pressure of
the steam in the boiler would then cause the water to rise within the Tube D, where,
in the absence of circulation it would speedily become cooled by the action of the
atmosphere, when it would contract to its normal length, and the alarm Valve would
be at once closed by the steam pressure at its back. The alarm whistle may be
placed either under the valve concentric with the Valve spindle, or, it may be placed
Vertically on the Valve Case.

page_text: Although the object of my present invention may be effected by the employment of
one or more supplementary steam pipes, I should by preference employ two such pipes,
both of which may be connected at their lower extremities to the cap A, which is fixed
to the. Boiler, their upper extremities may be fixed to the alarm Valve case, or branches
therefrom corresponding to two branches which may be provided in the cap A, thus,
the two Supplementary or Auxiliary steam pipes would form standards or supports for
the valve case.
The valve case may be fitted with a screw cap, through which the valve may be
examined, removed, or ground on its seat; the expanding pipe D, may be closed by a
screw cap to close its upper or outer end, and this cap may be fitted with a set screw
and lock nut by which the distance between the end of the valve spindle and the end
of the expanding pipe D, may be adjusted to the greatest nicety.
A small screw valve may be fitted in the cap A, so that, in the event of it being
found desirable to test the action of the apparatus, by means of this valve the steam
may be allowed to pass from the Supplementary or Auxiliary steam pipes or passages
into the expanding pipe D, or passages leading thereto by which the equilibrium of
pressure in all the pipes would be restored, the water in the expansion pipe D, would
then fall to the level of the water in the Boiler and the steam having filled the pipe D,
would cause it to expand, and thereby open the alarin Valve and sound the whistle,
and, in fact produce the same result as it the Boiler had become short of water.
The improvements and modifications herein described do not affect the essential
features of my previous invention which, in so far as the general principle and action,
and the materials employed in its construction is concerned; is applicable in either
case.
"The secondary object of my present invention is to combine with the low water
alarm apparatus herein described, a high pressure steam alarm, which I effect by
attaching a valve and whistle in a convenient position either on the low water
alarm valve case (on the steam side of the valve) or, on a branch or branches connected
therewith or to one or both of the supplementary steam pipes herein before referred to.
Such Valve being loaded either by a dead weight or spring and adjusted to the required
pressure, the action of the valve, being the same as a safety Valve which would rise and
open when the steam in the boiler exceeded the maximum Working pressure and the
escaping Steam would sound the alarm whistle which might be better heard at a
distance, or under other circumstances than the noise made by the blowing off of steam
through the ordinary safety valve or valves of the steam Boiler. The high pressure
steam whistle may be made to sound a different note to that produced by the low
water alarm so that the attendant or other persons might know the cause for which the
alarm was raised.
The nature of my Invention may be better understood on reference to the accom-
panying four sheets of drawings in which,
Fig. 1, (Sheet 1), is a sectional elevation of my improved and modified low water
alarm apparatus.
Fig. 2, (Sheet 2), is a sectional plan..
:
Fig. 3, (Sheet 2), is an elevation of the upper portion of my improved and modified
low water Alarm apparatus, fitted with the high-pressure steam alarm apparatus partly
in section.
Fig. 4, (Sheet 3), Represents my improved and modified Low Water alarm
apparatus, as applied to a horizontal Steam Boiler.
Fig. 5, (Sheet 3), Represents a further modification of the same.
Fig. 6, (Sheet 4), Represents one of the improved and modified low water alarm
apparatus, as applied to a vertical steam boiler."
The same letters of reference are used to mark similar parts throughout the several
views on all the four sheets of drawings.
a, is the bottom fixing or cap which is fixed to the boiler. b. b., are supplementary
or auxiliary steam pipes or tubes which form the standards or supports, for
which is
the top fixing or cap called the alarm valve case, containing the valve and whistle seat.
d, is the expanding pipe or tube. e, is the alarm or whistle valve. f, is the valve

page_text: spindle or stem. gg, is the opening or openings in the bottom Cap to the supple-
mentary pipes b, b. H, is the whistle for low water alarm. i, is a screwed cap which
closes the upper end of the expansion tube d. j, is the regulating screw and lock nut.
K, is a connecting tube descending from the bottom fixing, a, so as to bring the orifice
or passage leading to the expanding pipe d, to the low water level in the steam boiler.
1, is a screw plug fitted in the top cap e, by which access is obtained to the valve e,
and seat. M, is a valve fitted in the cap a, by which the action of the apparatus may
be tested. N, (Fig. 3 Sheet 2) is a valve seat and fixing which may be fitted into the
top fixing or Cap C, in place of the screw plug 1. o, is the valve. P, is the spindle.
Qis the whistle and R, the dead weight.
Having now particularly described and ascertained the nature of my Invention
and in what manner the same is to be performed I declare that what I claim is :-
(1), The Combination of parts and appliances constituting the improvements and
modifications of my low water alarm apparatus for Steam boilers substantially as
herein described and illustrated in Figs. 1, 2, and 4, on the accompanying drawings.
(2), The combination of parts and appliances constituting the improvements and
modifications of my low water alarm apparatus for Steam Boilers substantially as
herein described and illustrated in Figs. 5 and 6 of the accompanying drawings.
3, The application of a high pressure steam alarm apparatus and appliances, to and
in combination with my improved low water alarm apparatus for steam boilers,
substantially as herein described and illustrated in Fig. 3 of the accompanying
drawings.
4, The respective combinations of the parts forming my improved low water and
high pressure steam alarm apparatus and appliances for steam boilers, substantially
as herein described and illustrated on the accompanying four sheets of drawings.
K. HEBER KADFORD,
Agent for the Applicant.