Safety Devices for Steam Boilers for Automatically Preventing Escape of Steam on the Bursting of Pipes.
Year: 1896

page_text: Date of Application, 20th Oct., 1806
Complete Specification Left, 19th Jan., 1897-Acceoted, 27th Mar., 1897
Complete Specification Left, 19th Jan., 1897-Acceoted, 27th Mar., 1897
Communicated from abroad by GEORGE JOSEPH NICOLAS CARPENTIER, of the
Town of Newport News, in the County of Warwick, in the State of Virginia,
in the United States of America, Civil Engineer.]
Safety Devices for Steam Boilers for Automatically Preventing
Escape of Steam on the Bursting of Pipes.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 322, High Holborn, in the County of Middlesex,
6, Lord Street, Liverpool, and 6. Bank Street, Manchester, both in the County of
Lancaster, and Lower Temple Street, Birmingham, in the County of Warwick,
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
It is the object and purpose of the present invention to provide a steam-boiler
stop-valve connected by the steam-pipe leading to the engine, with means whereby
should the steam-pipe burst, the stop-valve will be automatically closed and the
steam shut off from the boiler. To accomplish this the valve-stem of the stop-
valve is slidingly arranged in the valve-casing and has its outer portion reduced
in diameter and projected through a hollow valve screw, the projecting valve-stem
being arranged to be engaged and moved by a piston-rod of a double-headed
piston. The piston-rod is operated in opposite direction by means of piston-heads
of different diameters disposed in a piston cylinder formed with steam-chambers
of different diameters, and each chamber being connected to a steam source,
and the cylinder being disposed with its larger steam-chamber and piston head
nearer to the valve than the smaller steam-chamber and piston. The end of the
piston-rod is arrenged in alignment with the stem of the valve and adapted to
engage with the end thereof to push the valve into closed position. A steam-pipe
leads from the main steam-pipe into the larger chamber of the cylinder, and a
steam-pipe leads from the boiler into the smaller chamber of the cylinder. The
whole device being placed so that in the ordinary action of the steam the pressure
on the left-hand face of the larger piston-head through the steam-pipe leading back
from the main steam-pipe, will be to keep the piston-rod away from contact with
the valve-stem; but should the pipe burst, the pressure on the larger piston-head
will be immediately removed, and the pressure on the smaller piston-head be
asserted and prevail in moving the piston to carry the piston rod inwardly and
against the valve-stem, closing the valve and immediately stopping the flow of
steam through the bursted pipe.

page_text: Safety Devices for Steam Boilers for Automatically Preventing
Escape of Steam on the Bursting of Pipes.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 322, High Holborn, in the County of Middlesex,
6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both in the County
of Lancaster, and Lower Temple Street, Birmingham, in the County of Warwick,
Civil 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 :-
This invention has relation to improvements in safety devices for steam-boilers;
and the object is to improve and simplify the safety device for a steam-boiler
shown and described in earlier Letters Patent No. 12,543 of 1896 wherein the
stop-valve of the boiler is operated through the agency or instrumentality of a
lever connection between the stem of the stop-valve and the piston-rod of the
safety device. In the present improvement it is designed to dispense with the said
actuating lever and arrange the double piston-cylinder opposite to the stop-valve,
and effect the closing of the stop-valve by the immediate and direct action of the
piston-rod of the double piston-cylinder on the valve-stem or rod of the stop-valve.
Other improvements are devised by interposing small auxiliary escape-pipes through
which steam may be let off in instances where a small pipe may have buret or any
apprehended danger demanding the engine to be stopped may exist or happen.
The improvements are fully and clearly illustrated in the accompanying drawings,
wherein :-
Figure 1 is a side view of the device, partly in section, showing the complete
device.
Figure 2 is a plan view of the device.
Figure 3 shows the device operatively connected to a steam-boiler of a common
construction.
A designates a steam-boiler in the head of which, at the usual and proper place,
is secured the casing A¹, of the stop-valve, having suitable connection to the
steam-pipe 1, leading to the engine. (Not shown.)
To the bonnet or cap 2, of the stop-valve may be secured a bracket 3, formed
with an open central portion, and having in the end adjacent to the stop-valve a
screw-threaded opening 4, in which is fitted a screw 5, provided with a hand-
wheel 6, to turn the end of the screw down and from the shoulder of the valve-stem
to shut or open the valve.
B designates the stop-valve which may be of any suitable design adapted to
close and open the steamway in the valve-chamber. The valve-stem 7 is slidingly
arranged in proper packing and has its outer portiou 8 reduced in diameter and
projected through the bore formed in the screw 5, so that the end of the reduced
portion of the valve-stem will project a sufficient distance beyond the outer end of
the screw to be operatively engaged and moved by the piston-rod of the double
piston, substantially as shown in the drawings.
The outer end of the bracket 3 is formed to have secured thereto the piston-
cylinder C. It will be perceived that in the present adaptation of the cylinder C
it is disposed reversely to the position disclosed in the said former cited Letters
Patent, the change of position being necessary to effect the improved operation
intended, the larger chamber in the cylinder being adjacent to the valve-stem of
the stop-valve and the smaller chamber being outward or farthest from the valve.
In construction the cylinder C is identical with that shown and described in the

page_text: Faid former cited Letters Patent, and comprises a piston-cylinder formed with two
piston-chambers 11, 11*, of different diameters, the larger 11x, being, as stated,
at the inner portion of the cylinder. Secured in and opening from the boiler is
pipe 12, the outer end of which opens into the smaller chamber 11 of the cylinder
to carry steam from the boiler into that chamber. The valve or turning-plug
usually inserted in this pipe, has been omitted in order that the action of the
steam in the smaller chamber of the cylinder shall be constant and not subject to
the manipulation of an interposed valve. In the inner end of the cylinder C is
fitted and secured a cylinder-head 14, through which the piston-rod D is slidingly
arranged and fitted, the end of the piston-rod also being projected through the
head of the interposed and supporting bracket, substantially as shown in the
drawings. The piston-rod D has secured thereon and fitted to the smailer chamber
of the cylinder C a piston-head 16, and at a determined point in the piston-rod is
another piston-head 17, fitting the larger chamber of the said cylinder and arranged
on the piston-rod to suit the stroke required.
At a convenient point in the cylinder is let in and securel a pipe 15, the other
end of which is secured in and opens into the steam-pipe 1, substantially as shown,
through which steam is admitted to the larger chamber of the cylinder from the
steam-pipe. The piston-rod D is disposed in direct longitudinal alignment with
the stem of the stop-valve and arranged with its inuer projecting end d, to
operatively contact with the projecting end of the valve-stem, so that the stop-valve
will be closed by the movement of the piston-rod.
In the pipe 15, at any convenient point or points leading from the said pipe, may
be arranged one or more small steam-escape pipes 22, provided with suitable
valves 22*, the object being to provide means for relieving the steam-pressure on
the piston-head in the larger chamber of the cylinder whenever a small steam-pipe
may have burst or any exigency happens which warrants the stopping of the
engine. These escape-pipes may be arranged at any suitable points in the return
pipe 15 and have their free ends opening into the air to carry the steam off without
danger to the surrounding objects.
As in the said cited Letters Patent No. 12,543, a small by-pass pipe 20 is
provided, having one end opening from the stop-valve and the other end opening
into the steam-pipe, and in the said by-pass pipe is disposed a stop-cock 21, to be
manipulated by the engineer, as occasion may require, to equalize the pressure and
permit a preliminary flow or charge of steam to the steam-pipe to act on the
larger piston-head and drive it back. The valve 21 is closed and remains closed
after the stop-valve is opened.
It will be observed that the area of the smaller cylinder and piston-head must be
larger than the area of the stop-valve in the steam-pipe in order that the former
will overcome the pressure in the latter.
It will now be perceived from the foregoing description, taken in connection
with the drawings, that in the ordinary action of the steam the pressure on the
left-hand face of the larger piston-head 17 through the pipe leading back from the
steam-pipe is to keep the piston in the position shown in Figure 1 of the drawings;
but should a pipe burst, the pressure on the piston-head 17 will be immediately
removed and the pressure on the smaller piston-head 16 assert its power and
prevail in moving the piston inwardly, carrying with it the stem of the stop-valve,
and thus immediately stopping the flow of steam through the burst pipe.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated
to me by my foreign correspondent, I declare that what is claimed, is :—
1. A safety device for steam-boilers, comprising a stop-valve form with a stem
projecting beyond its valve-casing, a steam-pipe leading from the valve-casing, a
steam-cylinder having chambers of different diameters and arranged with the
chamber of greater diameter next adjacent to the valve-stem, a pipe connection

page_text: leading from the boiler into the smaller chamber of the cylinder, a pipe connec-
tion leading from the steam-pipe into the larger chamber of the cylinder,
pistons in the cylinder having heads fitted to the respective chambers thereof,
and the rod of the pistons being arranged in alignment with the valve-stem and to
stand normally free from the projecting end thereof and to contact therewith and
close the stop-valve when the pressure in the steam-pipe ceases.
2. In a safety device for steam-boilers, the combination with the stop-valve the
boiler and the steam-pipe, of a steam-cylinder having chambers of different diameters,
a piston-rod provided with two piston-heads to fit the said chambers, a return
steam-pipe leading from the larger chamber to the steam-pipe, a steam-escape pipe
in the return steam-pipe, and a valve in the escape-pipe.
10.1 .
T
2007
W. P. THOMPSON & Co.,
Of London, Liverpool, Manchester, and Birmingham,
Patent Agents for the Applicant.