Improvements in Apparatus for Preventing the Escape of Steam from Steam Boilers in case of Rupture of the Steam Pipe, and applicable to other Vessels Containing Fluid under Pressure.
Year: 1895

page_text: Date of Application, 7th Sept., 1895
Complete Specification Left 8th June 1396 Accepted. 1st Aug.. 1896
Date of Application, in sept., 1050
Complete Specification Left 8th June
1396 Accepted. 1st Aug.. 1896
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Preventing the Escape of Steam
from Steam Boilers in case of Rupture of the Steam Pipe, and
applicable to other Vessels Containing Fluid under Pressure.
I, LOUIS MARIUS VALENTIN BLANC, of 12 Rue du Gabon Paris, in the Republic
of France, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to apparatus which acts automatically and serves to prevent
accidents from the bursting of steam pipes in connection with marine and other
boilers by cutting off the communication between the boiler and the atmosphere as
soon as a rupture of the steam pipe takes place.
The device substantially comprises two cylinders of different diameter united to
form what 1 will term a compound cylinder, two pistons of different diameters
working in said cylinders and rigidly connected together, a valve in the main steam
pipe and actuated by the movement of these compound pistons; a handle for raising
the valve, another cylinder communicating with the main steam pipe in which
cylinder two rigidly connected pistons move, a spring arranged to control these
pistons, the resistance of which spring is slightly smaller than the pressure exerted by
the steam at full pressure on the pistons, openings in the cylinder wall communicating
with the atmosphere; a pipe connecting the said cylinder to the boiler; another pipe
connecting this cylinder to the top of the first mentioned cylinder; a cock arranged
in the last named pipe and another cock inserted between the pipe which connects
the two cylinders and the other pipe which communicates with the boiler, this latter
cock serving for the optional closing of the valve in the main steam pipe.
I also provide a blow off pipe for the compound cylinder, and two holes in the
valve in the main steam pipe to permit of the automatic lifting of this valve from its
seat when the main stop valve-box is opened.
OPERATION.
At the moment of starting, the valve in the main steam pipe is lifted by means of
As the main
its actuating handle and subsequently the main stop valve is opened.
steam pipe then contains steam at full pressure, the resistance of the spring above
referred to is overcome and the pistons controlled by the spring are lifted and the
space between the pistons is thereby placed in communication with the atmosphere,
and by reason of the communicating pipe before referred to the top of the compound
cylinder is also placed in communication with the atmosphere.
As the bottom surface of the lower compound piston is subjected to the pressure of
the steam, it follows that the valve in the main steam pipe will remain open and that
the flow of the steam will take place in the usual manner.
If a rupture occurs in the main steam pipe, the pressure therein falls abruptly and
the spring controlled pistons then descend and close the holes in the cylinder wall and
place the annular space between the pistons in communication with the boiler, where-
upon the steam will act by its pressure upon the upper surface of the compound
piston, and since the diameter of the upper compound piston is larger than that of the
lower compound piston, the pistons will descend and instantly close the valve in
the main steam pipe. All communication between the boiler and the main steam
pipe is thus cut off and risk of accident is obviated.
It is to be observed that at the moment of starting, when the spring controlled

page_text: pistons are in their lower position, a communication exists between the pipe connecting
the two cylinders and the pipe passing to the top of the compound piston cylinder..
Care must therefore be taken that the cock before referred to in the former of these
pipes is previously closed in order to prevent the steam from acting upon the top
surface of the upper compound piston, whereby the valve would be prevented from
opening.
When a rupture of the steam pipe has occurred and the apparatus has acted, the
main stop-valve is then closed, the communication between the cylinder containing
the spring controlled pistons and the boiler is stopped by closing an appropriate cock
and the cock before referred to in the pipe between the two cylinders is shut.
When
the repair has been effected, the working conditions will be the same as they were
initially.
If at the moment of opening the main stop valve, the valve in the main steam pipe
controlled by this apparatus were resting upon its seat, the lifting of this valve would
be automatically effected by reason of the holes provided therein. In fact the lower
compound piston would be slightly lifted, the steam would pass through the holes
provided in the aforesaid valve and as soon as the pressure below the valve becomes
sufficient, the valves and connected pistons would rise and the normal state of things
would be thus re-established.
Finally in order to permit of closing the valve in the main steam pipe at any
moment and at the slightest irregular noise in the machinery, a cock is inserted
between the pipe which connects the spring piston cylinder to the boiler, and
the pipe which connects the two cylinders. A workman provided with a proper key
can, by opening this cock, effects an immediate closing of the valve in the main
steam pipe, because the steam of the boiler is thereby sent directly into the compound
piston cylinder at the top of the upper compound piston.
In case a number of boilers are working together, my safety device is placed upon
each steam pipe connecting the boiler to the main steam pipe, and prevents in a
reliable manner the explosion from being transmitted from one boiler to the other, in
case an explosion of one of the same should occur. In fact as soon as an explosion
takes place, the pressure falls instantaneously in all the steam pipes and the different
valves close instantaneously and thus cut off all communication between the several
boilers and between each of them and the atmosphere.
I reserve to myself to apply my safety device to any steam boiler or battery
of steam boilers, and in general to any installation utilizing a fluid under pressure.
I moreover expressly reserve to myself to replace at will the ordinary main stop
valve by any other means of closing and to construct each of these devices of any
appropriate material, and in any suitable form and dimensions.
Dated this 7th day of September 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Apparatus for Preventing the Escape of Steam
from Steam Boilers in case of Rupture of the Steam Pipe, and
applicable to other Vessels Containing Fluid under Pressure.
I, LOUIS MARIUS VALENTIN BLANC, of 12 Rue du Gabon, Paris, in the Republic
of France, 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 :-
My invention relates to an automatic device intended to prevent the occurrence of
accidents consequent upon the bursting of steam pipes in installations of marine

page_text: or other boilers, by cutting off all communication between the boiler and the
atmosphere immediately upon the bursting of a pipe.
In the accompanying drawings
Figure 1 is a general view of my safety device or automatically closing valve
in sectional elevation.
Figure 2 is a detail view of a portion of the device upon a larger scale. Upon
the main steam pipe a leading from the boiler C to the machinery is first arranged
the ordinary stop valve b, after this a valve box d upon which are fitted the
cylinders ef of unequal diameters, which serve as a cover for the said valve box.
The valve g arranged in the box d, allows the passage of the steam from the
boiler to the pipe a when raised, and completely interrupts such passage of the steam
when it is resting upon its seat.
The valve moves as a whole with the pistons p, pl which are mounted upon
the same rod and slide easily in the cylinders e and f. These pistons can be moved
directly by hand by means of the handle h but they are also moved, at the
proper moment, by the steam coming from the boiler C, the handle then serving
only to indicate the position of the valve g by means of a scale marked upon it.
Upon the pipe a is also arranged, at a short distance from the valve-box d, a
cylinder in which moves a piston k rigidly connected with the two drop valves k¹²,
and from which lead two pipes 1, 1', of which leads directly to the boiler C and
is governed by the steam-cock 2, while the other pipe communicates with the
upper portion of the cylinder f. The cylinder j is also provided with an, orifice m
communicating with the atmosphere, and has arranged upon it a second cylinder P
in which a spiral spring R is located. The spring R acts directly in a downward
direction upon the piston k and the drop valves ¹, 2 by means of the rod 7, as is
clearly shewn in the drawings.
The resistance of this spring is calculated in such a manner as to be always
inferior to the force exercised by the steam coming from the boiler at full
pressure. For a boiler pressure of 22 lbs., for example, the spring employed should
be capable of resisting a pressure of about 16 to 18 lbs.
Now when steam at full pressure passes along the pipe a, the piston k and with
it the drop valves k', k² is lifted; the drop valve having thus left its seat the
pipe is placed in free communication with the air by means of the opening m,
whilst the drop valve being pressed upon its seat the steam in the pipe
cannot pass above the piston k. If on the other hand the pressure in the pipe a
suddenly falls, as a result of a fracture, the spring R causes the piston kand
with it the valves ¹² to descend, the drop valve 2 rests upon its seat and cuts
off the pipe from communication with the atmosphere, the drop valve ¹ leaves
its seat and places the pipes and in communication.
Finally, as accessories, a three way cock is arranged in the pipe near the
cylinder, a waste pipe t is provided in the lower portion of the cylinder and
openings are bored in the valve g to permit of the lifting of this valve,
should it have been allowed to remain upon its seat when the stop-valve ↳ was
opened. The action of the device is as follows.
When the machinery is being started the piston and valves are in their
lower position, the cock for admitting steam to the pipe is closed, and the
cock places the pipe 1, and consequently the upper face of the piston p', in
communication with the atmosphere.
First the valve g is raised by hand by means of the handle and the stop-
valve is then opened. As the pipe a now contains steam at full pressure the
resistance of the spring R is overcome and the piston k with valves k¹² is raised.
The cock is turned so as to place the pipe in communication with the
cylinder and the steam cock 12 of the pipe 7 is opened.
The upper face of the piston p' is thus in communication with the atmosphere
by means of the pipe 1, the cylinder j and the opening m, but the steam which
now fills the pipe is not able to pass above the piston k into the cylinder j as
the valve is closed.

page_text: The lower face of the piston p, which is rigidly connected with the piston
being acted upon by the pressure of the steam, it follows that the valve will
remain raised and the supply of steam to the engine will take place in the ordinary
manner.
If, however, a fracture should occur in the steam pipe a, the pressure beneath
the piston will suddenly fall and the said piston together with the valves k', k²
will descend under the action of the spring R, communication between the
pipe and the atmosphere is interrupted by the closing of the valve k³, the pipes
and being placed in communication owing to the opening of the valve
steam coming into the pipe thus passes into the pipe and so acts upon the
upper face of the piston p'.
; the
The diameter of the piston being greater than the diameter of the piston p,
both pistons descend and the valve is instantly closed. All communication
between the boiler C and the pipe a is cut off and the possibility of an accident
is prevented.
When a pipe has burst and the device has acted, the stop valve is closed,
the supply of steam to the pipe is stopped by closing the cock and the cock r
is so turned as to place the pipe in free communication with the air. When
the necessary repairs have been effected the conditions are the same as when the
engines were originally started.
If, at the moment of opening the stop-valve b, the valve а should have been
allowed to remain upon its seat, the lifting of the said valve will take place auto-
matically, owing to the openings with which it has been provided. This effect
will be produced by means of the piston p, which rests upon the valve and prevents
the steam from reaching the openings by passing round the guide rod of the valve,
which piston will be slightly raised at first, the steam will then pass through the
openings and, when the pressure beneath the valve g is sufficient, the whole
assemblage of parts will be raised and the normal conditions will be established.
Finally in order to permit of the closing of the valve g at any moment and on the
occurrence of the slightest unusual noise in the working of the machinery, a cock r¹ is
interposed between the pipes and as represented in Figure 1 of the drawings.
A workman provided with a key can by opening this cock, bring about the instan-
taneous closing of the valve g since the steam from the boiler is then conducted into
the cylinder above the piston p.
In the case of a series of boilers, my safety device arranged upon each steam pipe,
before the collecting conduit absolutely prevents an explosion being transmitted from
one boiler to another should an explosion of one of them take place. Because,
immediately upon the occurrence of an explosion, the pressure falls instantly in all the
steam pipes and the various valves thereupon close, thus cutting off all communication
between the boilers and between each one of them and the atmosphere.
My automatically and optionally acting safety device is capable of being applied to
any installation in which a fluid under pressure is the motive force.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. An automatically acting safety device for instantly cutting off all communication
between a steam generator and the atmosphere upon the bursting of a pipe, such
device essentially consisting of a valve arranged upon the steam pipe after the usual
stop valve, which first mentioned valve is rigidly connected with an assemblage of two
differential pistons which remain raised during the normal working of the engine but
which fall instantly and so close the valve should a fracture occur by the action of a
special piston arranged upon the steam pipe which causes the upper face of the first
mentioned assemblage of pistons to be put in communication with the atmosphere
when the steam is in the pipe at full pressure, but which conducts steam taken
directly from the boiler by means of a special pipe upon the upper face of the said
assemblage of pistons in such a manner as to cause such assemblage to descend when

page_text: the pressure has fallen in the main steam pipe consequent upon the bursting of a pipe,
substantially as above described and set forth.
2. In a safety device as in Claim 1, a valve g connected in such a manner as to be
capable of play by means of a guide rod to an assemblage of two differential
pistons p, p located in one box, the whole being capable of being lifted from without
by means of a handle h when starting the engine, such valve being provided with the
openings t t which allow the passage of the steam onto its lower face and as a result
causes it to rise should it have not been already raised by means of the handle h
previous to opening the stop-valve b.
3. In a safety device as in Claim 1, an arrangement for automatically controlling
the safety valve g comprising a piston k rigidly connected with two drop valves k¹ k³
which piston works in a cylinder j and is submitted on its lower face to the pressure
of the steam in the main steam pipe a and upon its upper face to the action of a
spring R the strength of which is slightly inferior to the force of the steam at full
pressure, in such a manner that the piston remains raised under normal working
conditions and depressed if the pressure should fall in the pipe a consequent upon
a fracture, substantially as above described and set forth.
Data in 81 dar of Iun 1806
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.