IMPROVED MEANS AND APPARATUS FOR THE SUPPLY OF HIGH PRESSURE HYDRANTS OR STAND PIPES
Year: 1878

page_text: LETTERS PATENT to James Henry Greathead, of No. 8, Victoria Chambers,
Westminster, in the County of Middlesex, and Montagu Durancé Martindale,
of No. 1, Beech View Villas, Anerley, in the County of Surrey, for the Inven-
tion of "IMPROVED MEANS AND APPARATUS FOR THE SUPPLY OF HIGH
PRESSURE HYDRANTS OR STAND PIPES."
Sealed the 7th February 1879, and dated the 21st November 1878.
PROVISIONAL SPECIFICATION left by the said James Henry Greathead and
Montagu Durancé Martindale at the Office of the Commissioners of Patents on
the 21st November 1878.
JAMES HENRY GREATHEAD, of No. 8, Victoria Chambers, Westminster, in the
County of Middlesex, and MONTAGU DURANCE MARTINDALE, of No. 1, Beech View
Villas, Anerley, in the County of Surrey. "IMPROVED MEANS AND APPARATUS FOR
THE SUPPLY OF HIGH PRESSURE HYDRANTS OR STAND PIPES."
In cases where a high pressure service is not available in the pipes and mains of
the water supply of a town or district for the purpose of extinguishing fires it is
necessary to rely almost entirely upon the use of fire engines for that purpose. The
object of the present Invention is to provide in such cases means by which all the
advantages of a high pressure supply can be secured without employing fire engines
and without establishing a general supplementary high pressure service on an
extensive scale or interfering with existing low pressure supply.
For this purpose we provide a system of small pipes which are charged with
water at a high pressure from an elevated cistern or accumulator. We introduce a
nozzle from one of these high pressure pipes into the hydrant stand pipe or other
branch of the low pressure main from which it is desired to obtain a discharge at
pressure sufficient for fire extinction. By causing a jet of the high pressure fluid to
issue from the nozzle into the current of low pressure fluid furnished by the main
LD 1

page_text: the velocity of the latter is increased, and the combined jet may then be employed
to command the height desired. For the purpose of regulating the pressure of the
combined jet above referred to we find it advantageous to provide an adjustible
valve worked by a piston or flexible diaphragm, subject to the pressure of the jet
in such a manner that when that pressure exceeds a certain amount the high
pressure jet is reduced or entirely cut off.
It is to be understood that in parts of a town or district where the ordinary
pressure of the mains is sufficient for fire extinction, it is not necessary to apply the
high pressure service above referred to, which would therefore be provided on a
moderate scale for only those portions of the mains or pipes where the pressure is
insufficient for the maximum height required. This provision, without interfering
with the ordinary uses of these mains or pipes, thus renders their supply available
for the greater pressures that are occasionally required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Henry Greathead and Montagu Durancé Martindale in the Great
Seal Patent Office on the 20th May 1879.
JAMES HENRY GREATHEAD, of No. 8, Victoria Chambers, Westminster, in the
County of Middlesex, and MONTAGU DURANCE MARTINDALE, of No. 1, Beech View
Villas, Anerley, in the County of Surrey. "IMPROVED MEANS AND APPARATUS FOR
THE SUPPLY OF HIGH PRESSURE HYDRANTS OR STAND PIPES."
In cases where a high pressure service is not available in the pipes and mains of
the water supply of a town or district for the purpose of extinguishing fires it is
necessary to rely almost entirely upon the use of fire engines for that purpose. The
object of the present Invention is to provide in such cases means by which all the
advantages of a high-pressure supply can be secured without employing fire engines
and without establishing a general supplementary high pressure service on an exten-
sive scale or interfering with existing low pressure supply.
For this purpose we provide a system of small pipes which are charged with water
at a high pressure from an elevated cistern or accumulator. We introduce a nozzle
from one of these high pressure pipes into the hydrant stand pipe or other branch
of the low pressure main from which it is desired to obtain a discharge at pressure
sufficient for fire extinction. By causing a jet of the high pressure fluid to issue
from the nozzle into the current of low pressure fluid furnished by the main, the
velocity of the latter is increased, and the combined jet may then be employed to
command the height desired. For the purpose of regulating the pressure of the
combined jet above referred to we find it advantageous to provide an adjustable
valve worked by a piston or flexible diaphragm, subject to the pressure of the jet
in such a manner that when that pressure exceeds a certain amount the high pres-
sure jet is reduced or entirely cut off.
It is to be understood that in parts of a town or district where the ordinary
pressure of the main is sufficient for fire extinction, it is not necessary to apply the
high pressure service above referred to, which would therefore be provided on a
moderate scale for only those portions of the mains or pipes where the pressure is
insufficient for the maximum height required. This provision, without interfering
with the ordinary uses of these mains or pipes, thus' renders their supply available
for the greater pressures that are occasionally required.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is a vertical section of a hydrant arranged according to our Invention. A
is the branch from the main pipe supplying water at moderate pressure, its quantity
being determined by a sluice or other suitable valve governing the passage to the
pipe A in the usual way; B is a branch from a pipe of comparatively small size
supplied with water at high pressure. The supply by the branch B is also governed
by a sluice or other valve; the branch B bending upwards, terminates in a nozzle
b, directed into the ascending limb of the hydrant, and beyond this nozzle may be
fixed one or more trumpet mouthed guide tubes C, as shewn in Fig. 1, for the pur-
pose of obtaining several successive impulses from the central stream. The ordinary
hose or pipe being screwed on to the hydrant at D, the apparatus is worked in the
following manner-Water at the low pressure is admitted by the branch A to fill
the hydrant; water at the high pressure is then admitted by the branch B, and the
stream of this water issuing at high velocity by the nozzle b imparts a portion of
its velocity to the low pressure water supplied by A, thereby producing in the hose
a pressure greater than that of the low pressure supply and less than that of the
high pressure supply. By properly proportioning the volumes of low and high
pressure water, an intermediate pressure can be obtained sufficient to command a
jet of considerable height, such as is usually required for fire extinction. Thus by

page_text: the expenditure of a comparatively small quantity of very high pressure water con-
veyed by pipes of small dimensions, jets of large volume are obtained from the
ordinary low pressure supply without subjecting the low pressure pipes to such
pressure as would be required to command the jets and without interfering with
the ordinary uses of those pipes. Fig. 2 represents a vertical section of a stand pipe
similarly fitted with a high pressure nozzle according to our Invention. The low
pressure branch A and the high pressure branch B are both in this case made
separable from the service pipes which supply them and are attached thereto by
screwed unions when required for use. The nozzle may be fitted with a cone
adjustable by a screw E, to regulate the high pressure stream; or the high pressure
stream may be governed automatically by the pressure in the discharge pipe D; by
the arrangement shewn in Fig. 2ª a small cylinder E¹ is made to communicate by a
passago e with the discharge pipe D. The cylinder is fitted by a piston F, pressed
on by a spring, the force of which can be adjusted by a screw nut f. The piston
rod is linked to one arm of a lever G, to the opposite arm of which is linked the
cone valve fitting the nozzle b. When the pressure in D is sufficient to move the
piston Fin opposition to the spring, the passage through the nozzle b is more or less
throttled by the advance of the cone within it, and the high pressure stream being
thus reduced in volume, the pressure in D resulting from its action is likewise
.reduced; a flexible diaphragm may obviously by substituted for the piston F.
Fig. 3 represents a longitudinal section of a similar jet arrangement, according to
our Invention, applicable to fire engines. It consists of a hydrant pipe having a
branch A connected by hose or otherwise to a low pressure pipe or to auy neigh-
bouring supply of water at low pressure. The branch B is connected to the
discharge of the fire engine pumps, and a hose is screwed on to the mouth of the
pipe at D. The high pressure discharge of the fire engine giving motion to the low
pressure supply creates in the hose an intermediate pressure, as already described,
and thus pumps discharging a comparatively small volume of water at a very high
pressure are made available for producing jets of larger volume at lower pressure.
Having thus described the nature of our Invention and in what manner the same
is to be performed, we claim,
Rendering a low pressure water main available for supplying a fire hydrant or
stand pipe by the application of a high pressure jet therein, substantially as herein
described.
In witness whereof, I, the said James Henry Greathead, have hereunto set
my hand and seal, this Twentieth day of May, in the year of our Lord One
thousand eight hundred and seventy nine.
J. H. GREATHEAD. (L.S.)