Improvements in Devices for Preventing Shocks Due to the Starting or Sudden Stoppage of the Flow of Liquids in Pumps, Tubes, Pipes, Conduits, or the like.
Year: 1896

page_text: Date of Application, 6th Aug., 1896
Complete Specification Left, 27th Apr., 1897-Accepted, 5th June, 1897
PROVISIONAL SPECIFICATION.
Improvements in Devices for Preventing Shocks Due to the Starting
or Sudden Stoppage of the Flow of Liquids in Pumps, Tubes,
Pipes, Conduits, or the like.
A communication by JEAN PIERRE SERVE, of Caluire et Cuire (Rhône), in the
Republic of France, Engineer.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E: of The Agency for
Foreign Patent Solicitors of 6, Lord Street, Liverpool and 6, Bank Street,
Machester both in the County of Lancaster, 118, New Street, Birmingham in
the County of Warwick and 322, High Holborn in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
'
This invention relates to that class of device employed for preventing shocks
called water hammers, due to the starting or sudden stoppage of the flow of
liquids in pumps, tubes, pipes, conduits or the like, and has for its object to provide
means for obtaining this result in a more efficacious manner than by the use of air
reservoirs generally employed in which the air is rapidly absorbed by the liquid with
which it is in direct contact.
The invention consists essentially in the use of elastic chambers which are placed
inside the pump and the pipes or liquid conduits, such chambers being formed by a
casing of flexible and impervious material enclosing either the air or other gas
compressed at a pressure in proportion to that of the liquid or flexible material
containing interposed air, in such a way that the gas is not in direct contact with
the liquid, and so that the chamber thus formed may easily yield and afford an
elastic support to the liquid at the moment of its starting and of its sudden
stoppage.
The name of hydro-reducer has been given by the inventor to these elastic
chambers, the arrangement and mode of fitting of which depend upon the various
applications which may be made thereof, and which will now be described in this
specification.
In order to realise the application of the invention to pumps with plunger pistons,
there is interposed in the joint at the bottom of the pump, which is preferably
somewhat enlarged at this point, a disc or sheet of india-rubber or other flexible
material which is provided with a pouch of conical or rounded form in which air
may be compressed to a pressure which may be desired by means of a small conduit,
which is tightly closed by screwing up the joint with the addition of india-rubber
solution, in order to ensure the hermetic closing of this joint. The pouch or
pocket is held in place in the interior of the pump by means of a grating of
perforated metal having the same form as the pouch. The bottom plate of the
pump is suitably rounded or dished in such a way as to reserve behind the india-
rubber disc a chamber which may be filled with compresed air by means of an
opening provided with a closing valve, or which may be simply filled with spongy
india-rubber formed of a great number of irregular alveoles filled with air in order
to impart to it a great elasticity:
It is understood that at each stroke of the plunger, the gas or elastic material

page_text: contained in the chamber furnishes an elastic support to the liquid forced back, which
may flow then without a sudden shock through the orifice leading into the valve box
of the pump.
It is understood that the orifice leading to the valve box may be placed at the end
of the pump barrel and in' this case the cushioning arrangement will be placed
laterally in the body or barrel of the pump.
It is obvious that in the arrangement herein before described, it is not necessary to
increase the dimensions of the part of the pump containing the cushioning device and
that the air chamber arranged at each side of the india-rubber disc may have
suitable forms, or may be for instance semi-spherical.
There may also be arranged on one of the sides of the india-rubber disc a perforated
grating in order to admit of air being injected into the external pocket to a greater
pressure than that which is introduced into the internal pocket.
Finally, for greater simplicity there may in certain cases be employed an elastic
disc or plate without an internal pocket, or even a simple indiarubber ball filled
internally with compressed air or spongy india-rubber, the disc or plate like the ball
being maintained as before in the interior of the body of the pump by means of a
grating of perforated sheet metal.
In the case of a double acting pump, the end thereof through which the piston
rod passes must be arranged in a special manner. The cover bearing the stuffing
boxes is provided with a sleeve projecting into the interior of the barrel of the
pump which is suitably increased in diameter at this point, and it is on this sleeve
that the india-rubber cushion, filled as hereinbefore mentioned with spongy india-
rubber or better still with compressed air, inserted by means of a small conduit
passing through the joint of the pump, is fitted. It is of advantage in this case to
provide a part of the chamber or cushion in contact with the sleeve, with several
layers of fabric or wire gauze in order to prevent it bending under the action of the
liquid acting on its surface.
When the invention is to be applied directly to pipes or mains in which water is
subjected to sudden movement, the cushioning devices are arranged in such a way as
to be capable of being interposed in the joints of the pipes in as large a number as
may be desired for the object to be attained.
The arrangement preferably employed consists of two cylindrical concentric
casings of metal, the inner one of which is perforated and has a diameter equal to,
or larger than that of the pipe for carrying the liquid; the other casing has a small
pipe or nozzle for the injection of air which is provided with an air tight closing
valve. Between these two casings is interposed an india-rubber tube, the ends of
:which are hent back in such a way as to engage between the flanges of the two metallic
casings, so that when these flanges are pressed together the apparatus forms
a solid piece enclosing a tight annular chamber which is filled with compressed air
at the desired pressure and which may be easily fitted between two successive pipes
of the conduit.
In this manner the india-rubber tube remains pressed by the compressed
air against the perforated inner pipe and at the moment of a stoppage or sudden
⚫ starting of the flow of the liquid this flexible tube affords an elastic resistance to
the liquid, thus avoiding any sudden shock and any deleterious shaking or bursting
of the pipe.
" It is of course understood that the flexible tube instead of being of india-
rubber may be made of any elastic material, such as leather, impervious canvas, or
the like, and that it may be strengthened at certain points, or have undulations
- which facilitate its extension.
The device may also be arranged in such a way that the elastic chamber is
directly interposed in the joint of two successive pipes. In this case the ends of
these pipes are provided with enlargements in which is lodged a ring or hollow plug
of indiarubber filled with compressed air by means of a tube or nozzle with a valve
and which is maintained internally, as before, by means of a grating or perforated
pipe.

page_text: When the device is especially intended for use in the mains of a household
water-supply, the flexible indiarubber piece is arranged in the form of a bell and
is maintained between two metallic casings of the same form, the inner one being
perforated and the other provided with an opening for the introduction of
compressed air. This bell encloses the air chamber, fits on the extended end of
the pipe, and is contained in an enlargement of the adjacent pipe, so that the liquid
is then forced to follow a bell shaped course. The elastic action of the cushioning
device thus formed, may be further completed by adding to the next pipe a flexible
ring filled with compressed air as has been herein before shown.
Finally, the hydro-reducer may also be formed of a pipe, having for instance the
same diameter as the supply pipe and provided at its periphery with several
funnel-shaped pieces with which it communicates by means of perforations. In
these funnels, hollow cones of india-rubber filled with compressed air are arranged,.
the plates or covers for closing the funnels being either flat or preferably suitably
dished or rounded in order to allow of a second elastic chamber being forined which
may be filled with flexible india-rubber or compressed air if so desired.
Dated this 5th day of August 1896.
WM. P. THOMPSON & Co.,
Agents..
Improvements in Devices for Preventing Shocks Due to the Starting
or Sudden Stoppage of the Flow of Liquids in Pumps, Tubes,
Pipes, Conduits, or the like.
A communication by JEAN PIERRE SERVE, of Caluire et Cuire (Rhône), in the
Republic of France, Engineer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 322 High Holborn in the County of Middlesex,
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 relates to that class of device employed for preventing shocks
called water han.mers, due to the starting or sudden stoppage of the flow of liquids
in pumps, tubes, pipes, conduits or the like, and has for its object to provide means
for obtaining this result in a more efficacious mauner than by the use of air
reservoirs generally employed in which the air is rapidly absorbed by the liquid
with which it is in direct contact.
The name of hydro-reducer has been given by the inventor to the elastic
chambers designed by him for the above purpose, the arrangement and mode of-
fitting of which chambers depend upon the various applications which may be made
thereof, and which will now be described in this specification.
Figure 1 is a longitudinal section of a pump with plunger pistons provided or
fitted with my improvements;
Figures 2, 3, 4 and 5 are views in section showing various elementary
arrangements of devices for preventing shocks in pumps ;
Figure 6 is a sectional view showing the application of the invention to
double acting pump;
Figure 7 is a longitudinal section of a device for preventing shocks in pipes;

page_text: Figures 8 and 9 are detail views;
Figure 10 is a longitudinal section of another arrangement for preventing shocks
in pipes;
Figure 11 is a longitudinal section of a means for preventing shocks in the mains
of a household water supply;
Figure 12 is a transverse section of another modification of a device for preventing
shock in pipes.
In order to realise the application of the invention to pumps with plunger
pistons, as in Figure 1, there is interposed in the joint at the bottom C of the
pump A, which is preferably somewhat enlarged at this point, a disc or sheet D of
indiarubber or other flexible material which is provided with a pouch a of conical
or rounded form in which air may be compressed to a pressure which may be
desired by means of a small conduit 6 which is tightly closed by screwing up the
joint with the addition of india-rubber solution in order to ensure the hermetic
closing of this joint. The pouch or pocket a is held in place in the interior of the
pump by means of a grating E of perforated metal having the same form as the
pouch. The bottom plate C of the pump is suitably rounded or dished in such a
way as to reserve behind the india-rubber disc D a chamber d which may
be filled with compressed air by means of an opening e provided with a closing
valve, or which may be simply filled with spongy india-rubber formed of a
great number of irregular alveoles filled with air in order to impart to it a
great elasticity.
It is understood that at each stroke of the plunger B, the gas or elastic material
contained in the chambers a and d furnishes an elastic support to the liquid forced
back which may flow then without a sudden shock through the orifice leading
into the valve box of the pump.
It is understood that the orifice f leading to the valve box may be placed at the
end of the pump barrel A and in this case the cushioning arrangement will be
placed laterally in the body or barrel of the
pump.
The arrangement shown in Figure 2 is the same, only the body of the pump is
not enlarged at its end, and the pocket a has the form of a hemisphere. In the
same way the chamber d may be filled with compressed air or with spongy
indiarubber g as shown in the figure.
In the arrangement shown in Figure 3 the chamber a is separated from the
plate D by means of a perforated metal grating F interposed in the joint.
In this manner it is possible to inject into the chamber d compressed air to
a greater pressure than that which is introduced into the internal chamber a.
In the arrangement shown in Figure 4, the chamber a is dispensed with, and the
elastic support for the liquid is formed by a simple elastic plate D held in
place internally by a perforated sheet metal grating E, the chamber existing
between this plate D and the bottom C being, as previously, filled with spongy
indiarubber g or compressed air introduced by means of an opening e provided
with a retaining valve.
Finally in the simpler modification shown in Figure 5 the elastic support is
furnished to the liquid by means of a ball G filled with air or spongy indiarubber,
and which is maintained interposed between the grating E and the bottom C which
assumes exactly a corresponding form.
In the case of a double acting pump, Figure 6, the end thereof through which
the piston rod passes must be arranged in a special manner. The cover C bearing
the stuffing boxes H is provided with a sleeve h projecting into the interior of the
barrel A of the pump which is suitably increased in diameter at this point and it
is on this sleeve h that the india-rubber cushion I, filled as herein before mentioned
with spongy india rubber or better still with compressed air inserted by means of
a small conduit 6 passing through the joint of the pump, is fitted. It is of advantage
in this case to provide a part of the chamber or cushion I in contact with the
sleeve with several layers of fabric or wire gauze i in order to prevent it bending
under the action of the liquid acting on its surface.

page_text: When the invention is to be applied directly to pipes or mains in which water is
subjected to sudden movement, the cushioning devices are arranged in such a way
as to be capable of being interposed in the joints of the pipes in as large a number
as may be desired for the object to be attained.
The arrangement preferably employed is shown in Figure 7, and consists of two
cylindrical concentric casings of metal, the inner one k of which is perforated and
has a diameter equal to, or larger than that of the pipe for carrying the liquid
the other casing has a small pipe or nozzle m for the injection of air which is
provided with an air tight closing valve. Between these two casings is interposed.
an india-rubber tube K, the ends of which are bent back in such a way as to
engage between the flanges n n of the two metallic casings, so that when these
flanges are pressed together the apparatus forms a solid piece enclosing a
tight annular chamber o which is filled with compressed air at the desired
pressure and which may be easily fitted between two successive pipes of the
conduit.
In this manner the india-rubber tube K remains pressed by the compressed air
against the perforated inner pipe k and at the moment of a stoppage or sudden
starting of the flow of the liquid this flexible tube K affords an elastic resistance
to the liquid, thus avoiding any sudden shock and any deleterious shaking or
bursting of the pipe.
It is of course understood that the flexible tube K instead of being of
india-rubber may be made of any elastic material, such as leather, impervious
canvas, or the like, and that it may be strengthened at certain points, or have
undulations which facilitate its extension, as in Figures 8 and 9.
The device may also be arranged in such a way that the elastic chamber is.
directly interposed in the joint of two successive pipes as in Figure 10. In this
case the ends of these pipes L are provided with enlargements in which is lodged a
ring or hollow plug M of indiarubber filled with compressed air by means of a tube.
or nozzle m with a valve and which is maintained internally as before, by means of
a grating or perforated pipe k.
When the device is especially intended for use in the mains of a household water
supply, as in Figure 11, the flexible indiarubber piece N is arranged in the form
of a bell and is maintained between two metallic casings of the same form, the-
inner one p being perforated and the other 7 provided with an opening m for the
introduction of compressed air. This bell enclosing the air chamber o, fits on
the extended end of the pipe L, and is contained in an enlargement P of
the adjacent pipe L' so that the liquid is then forced to follow a bell shaped
course. The elastic action of the cushioning device thus formed, may be further.
completed by adding to the next pipe L' a flexible ring M filled with compressed air-
as has been hereinbefore shown.
Finally the hydro-reducer may also be formed as in Figure 12 of a pipe e having-
for instance the same diameter as the supply pipe and provided at its periphery
with several funnel-shaped pieces R with which it communicates by means of
perforations r. In these funnels R, hollow cones of india-rubber S filled with.
compressed air are arranged, the plates or covers T for closing the funnels being
either flat or preferably suitably dished or rounded in order to allow of a second.
elastic chamber u being formed which may be filled with flexible india-rubber or
compressed air if so desired.
Having now particularly described and ascertained the nature of the said inven-..
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
1. In combination with a pump; a plate or disc of flexible and impervious..
material provided on one side with a pouch or chamber filled with compressed
air; a grating of the same form as said pouch to maintain it in place in the
pump; and a chamber filled with compressed air formed on the opposite face of

page_text: the flexible plate by the bottom of the pump; substantially as and for the purpos:
set forth.
2. In combination with a pump; two sheets of flexible material each so
supported by metallic gratings as to form between them, a chamber intended to
receive compressed air and so placed within the pump as to form between the
second sheet and the bottom of the pump, a second chamber in which air may be
compressed at a pressure superior to that in the first chamber, substantially
as herein before described and for the purpose set forth.
3. In combination with a double acting pump; an air cushion formed of flexible
and impervious material interposed between a grating and the bottom of the pump,
and fitted by a central cylindrical passage over an internal sleeve formed on the
cover and giving passage to the piston rod; said central cylindrical part being
provided internally with metallic fabrics, substantially as described and for the
purpose set forth.
4. In combination with a water pipe or conduit; a tube of flexible and
impervious material interposed between an unperforated external metal pipe
and a perforated internal pipe, and having its ends secured hermetically between
the joints or flanges of said metallic pipes, so as to form between it and
the unperforated external metal pipe, a chamber intended to receive air compressed
to the desired pressure, for the purpose and in the manner hereinbefore set
forth.
5. In combination with a pipe or conduit; an elastic chamber in the form of a
bell intended to be filled with compressed air, and which consists of a bell-shaped
piece of flexible and impervious material, so maintained between two rigid parts of
similar form, the interior one of which is perforated, whilst the external one is
unperforated, and adapted to be fitted on a prolongation of a pipe or conduit for
liquid in movement, as to force such liquid to take a bell-shaped course and to
finally flow into an external metallic casing fitting on the following pipe, as and for
the purpose hereinbefore set forth.
6. In combination with a pipe, an elastic chamber formed of a hollow ring of
flexible and impervious material, filled with compressed air and interposed in the
joint of two successive pipes, suitably enlarged at their adjacent ends, and a
perforated tube supporting internally the central part of the hollow ring, in the
manner and for the purpose herein before indicated.
7. In combination with a pipe or conduit, chambers of conical shape formed
of flexible and impervious material, filled with compressed air and retained in
suitable casings formed or arranged on the periphery of the pipe; the casings
of said chambers being in communication with the interior of the pipe by means of
· perforations formed in said pipe, as and for the purpose set forth.
Dated this 26th day of April 1897.
WM. P. THOMPSON & Co.,
Agents.