An Improved Safety Appliance for Boilers and other like Vessels.
Year: 1892

page_text: Date of Application, 16th Apr., 1892
Complete Specification Left, 3rd Oct., 1892-Accepted, 5th Nov., 1892
PROVISIONAL SPECIFICATION.
An Improved Safety Appliance for Boilers and other like
Vessels.
I JAMES JOHN LARKIN of East Jarrow in the County of Durham, Mechanical
Engineer do hereby declare the nature of this invention to be as follows:-
Vessels used for generating or storing fluid such as for example steam acids
inflammable explosive or poisonous gases are generally provided with one or more
pipe or pipes for drawing off from the boiler or vessel the fluid contained or
generated therein but such pipe or pipes may act as a channel or channels through
which the said fluid may re-enter the said boiler or vessel.
My invention has for its object to prevent the violent entrance of any such fluid
into the boiler or vessel from which it is desired to exclude the said fluid as for
example in the case where a vessel or boiler has to be entered by persons for
inspection cleaning or repairs.
Stop cocks non-return and other valves have been employed for effecting the
object of my invention but they are liable to accidents causing leakage and do not
prove satisfactory in operation.
My invention consists in interposing at any convenient part in the pipe or pipes
and either inside or outside the said boiler or vessel an opening provided with a
cover. The said opening is arranged to look outwards from the boiler or vessel so
that on removal of the said cover any fluid flowing in the direction towards the
boiler or vessel would be interrupted at the point where the cover had been
removed and would tend to flow out of the opening in a direction away from the
boiler or vessel.
When the opening is formed in the pipe or pipes situated outside the boiler or
vessel a deflecting plate may be arranged in the said pipe or pipes to cause the
fluid to flow in a direction away from the boiler or vessel when the cover has been
removed.
The cover may be screwed on or bolted or fixed in any convenient way so as to
effect a tight joint.
The said cover may be formed of suitable metal curved or flat or may if desired
consist of a valve kept close by springs weights levers or other suitable means.
In the latter case the valve may act as a safety valve as well as serving the
purpose of this invention.
The pipe or pipes with the cover or covers may be placed in such a position
relative to the manhole or manholes and it may have such connection with the
manhole door or doors so that the said manhole door or doors cannot be removed
until the said cover or covers has or have also been removed.
Dated this 16th day of April 1892.
J. H. JOHNSON & CO.,
47, Lincoln's Inn Fields, London, Agents.
J. H. JOHNSON & CO.,
47, Lincoln's Inn Fields, London, Agents.
COMPLETE SPECIFICATION.
An Improved Safety Appliance for Boilers and other like
Vessels.
I JAMES JOHN LARKIN of East Jarrow in the County of Durham Mechanical
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 :-
Boilers or vessels used for generating or storing fluid such as for example, steam,

page_text: '
acids, or inflammable, explosive, or poisonous gases, are generally provided with a
pipe or pipes for drawing off from the boiler, or vessel, the fluid contained or
generated therein but such pipe or pipes may act as a channel or channels through
which the said fluid may re-enter the said boiler or vessel.
My invention has for its object to prevent the violent entrance of any such fluid
into the boiler or vessel from which it is desired to exclude the said fluid, as for
example in the case of two or more steam boilers passing their steam into a common
steam pipe when it is desired to shut off the steam from one of the boilers so
that it can be entered for inspection cleaning or repair whilst the other or others
of the boilers remains or remain in operation.
Stop cocks or non-return or other valves have been employed for effecting the
said object, but they are liable to accidents, cause leakage, and do not prove
.satisfactory in operation.
My invention consists in interposing at any convenient part in the pipe, or pipes
or in the shell, or body, of the boiler, or like vessel in proximity to the said pipe
The said
or pipes, an opening or passage provided with a removeable cover.
.opening or passage is arranged to open outwards from the boiler or vessel so that
on removal of the said cover any fluid flowing in the direction towards the interior
of the boiler or vessel, would be interrupted at the point where the cover had
.been removed and would flow out of the opening in a direction away from the
boiler or vessel. When the opening is formed in the pipe or pipes situated outside
the boiler or vessel a deflecting plate or deflecting plates may be arranged in the
said pipe or pipes to cause the fluid to flow in a direction away from the boiler
or vessel when the cover has been removed.
The cover may be formed of suitable metal curved or flat and it may be screwed
on, or bolted on, or fixed, in any convenient way so as to effect a tight joint or it
may if desired consist of a valve kept close by springs, weights, levers, or other
.suitable means and may then act as a safety valve as well as serving the purpose
of this invention.
The pipe or pipes with the cover or covers may be arranged in such a position
relatively to the manhole or manholes as to admit of the cover or covers being
connected with the manhole door or doors or their securing devices so that the
said manhole door or doors cannot be removed until the said cover or covers has,
or have, been removed.
I will describe with reference to the accompanying drawings means for carrying
out my invention but I do not restrict myself to the details illustrated as variations
may be made therein without departing from the nature of my said invention. In
the following description I will assume the vessel to which my invention is applied,
to be one of two or more steam boilers connected by a common. steam pipe it being
understood that the invention may be applied in a similar manner to vessels for
storing acids, inflammable, explosive or poisonous gases and the like where there
is any danger of injurious fluid entering a boiler or vessel from which it is desired
to exclude it.
Figures 1 and represent in vertical section and horizontal section respectively
a safety device constructed according to my invention. I have shewn with it
an arrangement for preventing the man-hole door being removed till the cover
of my improved device is removed but I do not limit myself to the use of such
an arrangement with my device.
Figure 3 shew's an arrangement for connecting the man-hole door or doors to the
safety device more suitable in cases where the said man-hole or man-holes is or
are situated at some distance from the safety device.
Figures 4 and 5 shew modifications of the arrangement for securing the man-
hole door.
Figure 6 shews a modification in the arrangement of my safety device.
Figure 7 shews another modification thereof and
T
• home the refates dosies combined with a anfety valve

page_text: boiler, B the manhole by which access can be had to the interior of the boiler
and B¹ the manhole door or cover fixed in position in the ordinary manner by
means of bolts or studs a passing through bars or bridges C and fixed by nuts b.
c is an opening in the shell A through which steam passes from the boiler to the
steam distributing pipe D into which pipe D the steam from another boiler or from
other boilers also passes. Between the opening cand the distributing pipe DI inter-
pose a safety device constructed according to my invention and consisting of a short
pipe or passage E divided by a transverse partition F into two chambers e e¹ there
being openings ff in the pipe or passage E above and below the partition F and
leading respectively into the two chambers e e¹. Bolted to the pipe or passage E
so as to enclose the openings, ff¹ is a hood or cover G which when fixed in position
completes a passage or communication between the two chambers e e' so that steam
from the boiler on its way to the distributing pipe D passes in a circuitous direction
through the pipe or passage E as shewn by the arrows. The steam distributing
pipe D may be provided as shewn at H with a non-return valve or non-return
valves to cut off when desired the communication between one boiler and another.
When access to the interior of the boiler is required the valve H should be closed
and the hood or cover G removed from the openings ff whereupon any steam
that may be in the boiler will pass therefrom through the opening f' into the
atmosphere. The manhole door B' may then be removed to obtain an entrance to
the interior of the boiler.
Should the valve H be left partly open or be defective so as to admit into the
chamber e steam from the other boiler or boilers in connection with the pipe D the
said steam will not enter the boiler A as it will be deflected by the partition F
through the opening into the atmosphere.
The hood or cover G may be so connected to or combined with the manhole door
or with the nuts by which the man-hole door is secured in position as to render it
impossible for the said manhole door to be opened before removing the hood or
cover G from the openings ff in the pipe or passage E. For this purpose there
may be formed in one with the hood or cover G a cap or cupped projection I which
when the cover G is fixed in position covers or encloses the nuts which secure
the manhole door B' in position so that the said nuts cannot be loosened before the
hood or cover G is removed. In cases where the manhole is situated at such a
distance from the tube E that it would not be convenient to secure the manhole
door by means of a projection from the hood or cover as in Figures 1 and 2 the
arrangement shewn in Fig. 3 may be employed which consists in providing the
manhole door with a cover K hinged to the boiler shell at k. To an eye i on this
cover is connected one end of a wire or other connector M, its other end being
secured to the hood or cover G. The length of the connector M and its place of
attachment should be such that when the hood G is fixed in position the said
connector will prevent the cover K from being raised to obtain access to the
fastenings of the manhole door. Instead of the cover K being hinged to the shell
of the boiler and made to extend over the manhole door as shewn in Fig. 3 it may
consist of a small hood or cover to cover the fastenings 6 only and it may be hinged
to the bars or bridges C as shewn in Fig. 4. Or instead of hinging the cover K to
the boiler shell or to the bridges C as described the said cover may be detached
and the flexible connector M after passing through an eye on the manhole door
เ
be secured to the interior of the cover K as shewn in Fig. 5 so that the strain on
the connector M when the hood or cover G is fixed in position will prevent the
cover K from being raised to obtain access to the nuts 6 or other fastenings of the
manhole door thus preventing the manhole door from being opened until the hood
or cover G has been removed. In cases where the manhole is situated in a plane
at right angles to or different from that in which the hood or cover G is situated
the flexible connector M may be conducted over suitably arranged guide rollers so
as to operate in the manner described to prevent the manhole door from being
opened before the hood or cover G is removed. Although I have shewn the

page_text: .
:
device for preventing the removal of the manhole door as covering both the
securing nuts it may cover only one if desired.
In the modified arrangement of the safety device illustrated by Fig. 6 a pipe E
is fixed inside the boiler at the opening c the said pipe being curved so that the
open end thereof faces another opening c³.
Surrounding the opening on the exterior of the boiler is a neck or collar N
provided with a close fitting hood or cover G which cover may be connected to the
manhole door by a connector M in the manner hereinbefore described. Inside the
boiler shell A and enclosing the open end of the pipe E is a chamber O communi-
cating with both the opening e* and the perforated pipe P situated in the steam
space of the boiler. If desired the chamber O may be made in one with the pipe E
and the neck or collar N may be dispensed with and the cover G be fixed to a
seating on the boiler shell. The steam from the interior of the boiler passes through
the perforations p into the pipe P and thence as indicated by the arrows through the
When it is desired to have
chamber and pipe E to the distributing pipe D.
access to the interior of the boiler the hood or cover G is first removed from the
neck or collar N so that any steam remaining in the boiler may escape before the
manhole door is opened and so that any steam that may pass from the other boiler
or boilers towards the boiler through the pipe E will not enter the boiler but will
pass through the openings into the atmosphere. Fig. 7 shews an arrangement
somewhat similar to that last described the chamber O and internal perforated
steam pipe P being omitted. The pipe E is connected to the interior of the shell A
at the opening c but instead of communicating with another opening in the same
plane as in Fig. 6 it communicates and passes through an opening situated at a
right or other angle to the opening c, the said opening c and the open end of the
pipe being surrounded by a neck or collar N provided with a cover G the said
cover being, if desired, connected to the manhole door by the connector M as
herein before described. Steam from the interior of the boiler passes through the
pipe E to the distributing pipe D as indicated by the arrows but when the cover G
is removed from the neck or collar N any steam from the distributing pipe entering
the pipe E will pass therefrom through the opening c³ into the atmosphere. In the
arrangement illustrated by Fig. 8 (in which my invention is combined with a safety
valve) the valve G also serves the purpose of the hood or cover G hereinbefore
described. The casting E' constituting the valve box is fixed to the shell of the
boiler over the opening c and is provided with a seating g for the valve G. The
valve may be acted upon by a spring h as shewn or by dead weight or a weighted
lever if desired. The pressure of the spring is maintained by a cross head m secured
to the casting E' by bolts n and nuts oo. The valve stem g³ passes through an
opening in the crosshead m and may be connected to the man-hole door by means
of a connector as herein before described with reference to the hood or cover G.
Formed in one with or connected to the casting E' is a pipe or passage E one end
of which is in communication with the distributing pipe D the opposite end entering
the casting E' below the valve G and being curved so that the open end faces the
said valve. A space is left between the interior of the casting E' and the pipe E for
the passage of steam from the interior of the boiler through the pipe E to the
distributing pipe D. In the case of excess of pressure in the boiler above the
When access
strength of the spring h the valve G will operate as a safety valve.
to the interior of the boiler is required the valve G can be removed or opened
thereby allowing any steam that may be in the boiler and also any steam that may
enter the pipe E from the distributing pipe D to escape into the atmosphere through
the valve seat g. I have shewn an arrangement for making the cover G act also
as a safety valve but I do not limit myself to the arrangement shewn.
q are drain pipes or passages through which water of condensation may pass from
the pipes or passages E. The said drain pipes or passages are of course provided
with cocks or means by which they can be closed if they be outside the boiler.
Any desired number of man-hole doors may be connected to a single hood or

page_text: cover G in the manner substantially as hereinbefore described so that neither of the
said man-hole doors can be removed before the hood or cover G is detached conse-
quently the liability of injury to persons who enter the boiler or other vessel to
which my invention is applied is entirely prevented.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A safety appliance for steam boilers and other vessels for containing fluids
(such for example as acids or inflammable, explosive, or poisonous gases or the like,
for preventing the entrance of steam or other fluid into the boiler or vessel when
the said boiler or vessel has to be entered by persons for inspection, cleaning or
repairs substantially as herein before described.
2. An appliance for preventing the entrance of steam to steam boilers or steam
or other fluid to a vessel from which it is desired to exclude such steam or other
fluid the said appliance consisting of a pipe or passage through which steam or other
fluid flows from the boiler or other vessel, the said pipe or passage having an
opening or openings therein fitted with a removable hood or cover and a partition
or diaphragm so arranged inside the pipe or passage that when the hood or cover is
removed any steam or other fluid flowing in the pipe or passage towards the interior.
of the boiler or other vessel will be caused to flow through the opening or openings
in the pipe or passage into the atmosphere substantially as herein before described
with reference to Figures 1. 2. and 3 of the accompanying drawings.
3. In a safety appliance for steam boilers and other like vessels a pipe or passage
arranged in the interior of the boiler or vessel through which pipe or passage steam
or other fluid passes from the said boiler or vessel to the distributing pipe the open
end of the said internal pipe or passage being opposite to or passing through an
opening in the boiler or other vessel the said opening being fitted with a removable
hood or cover which when removed allows any steam or fluid flowing through the
internal pipe towards the interior of the boiler or vessel to pass into the atmosphere
substantially as herein before described with reference to Figure 6 and Figure 7 of
the accompanying drawings.
4. In a safety appliance for steam boilers and other like vessels in combination
with a safety valve, a pipe or passage so arranged with reference to the safety
valve that when the valve is removed any steam or other fluid flowing through the
said pipe or passage towards the interior of the boiler or other vessel will pass into
the atmosphere through the opening which was controlled by the valve sub-
stantially as hereinbefore described with reference to Figure 8 of the accompanying
drawings.
5. A safety appliance for steam boilers and other like vessels the said appliance
consisting of a pipe or passage through which steam or other fluid passes from
the interior of the boiler or other vessel and an opening or openings in the
said pipe or passage or in proximity thereto provided with a removable hood or
cover substantially as and for the purpose hereinbefore described in combination
with means for connecting the said hood or cover to the man-hole door or man-
hole doors by which access is had to the interior of the boiler or other vessel
in such a manner that the said man hole door or man hole doors cannot be removed
without first removing or detaching the said hood or cover substantially as herein-
before described.
6. The safety appliance for steam boilers and other like vessels substantially as
hereinbefore described and illustrated by Figures 12 and of the accompanying
drawings whether or not the hood G be connected to the man hole door or doors
for the purpose described.
7. The combination and arrangement of parts constituting a safety appliance for
steam boilers and like vessels substantially as hereinbefore described and illustrated
by Figure 6 of the drawings in combination, or not, with means for connecting the
cover G with the man hole door or doors for the purpose described.

page_text: IT.
8. The combination and arrangement of parts constituting the improved safety
appliance hereinbefore described and illustrated in Figure 8 of the drawings in
combination or not with means for connecting the valve Ġ with the man-hole door
or doors for the purpose described.
Dated this 3rd day of October 1892.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.