Improvements in Apparatus for Preventing the Bursting of Water Pipes by Freezing.
Year: 1899

page_text: Date of Application, 25th May, 1899-Accepted, 1st July, 1899
COMPLETE SPECIFICATION.
Improvements in Apparatus for Preventing the Bursting of Water
Pipes by Freezing.
I, NEVIL MONROE HOPKINS, a Citizen of the United States, residing at No. 183,
Jefferson Place, in the City of Washington, District of Columbia, U.S.A., Elec-
trician, 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:
In my British Patent, No. 27,628, of December 31, 1898, I have shown a series
of expansion chambers applied to a water-pipe, and so arranged that the freez-
ing water or ice expands into the chambers without causing the pipe itself to
expand or burst.
The expansion chambers are filled with air, and are air-tight, the water nor-
mally being for the most part excluded from the chambers by the air which is
compressed by the water if it tends to enter too far into the chambers.
I have found, however, that when the flow of water is constant, long continued
and rapid, the air in the chambers is partially, if not wholly, withdrawn, owing
to the aspirating effect of flowing water.
According to my present invention, I provide means for supplying an addi-
tional quantity of air to the chambers so that they may always be filled to such
an extent as to exclude water therefrom under ordinary conditions, but which
is compressed to make room for freezing water and ice when required.
In the accompanying drawings-
Figure 1 shows a water-pipe system with my improvements applied;
Fig. 2 shows a detail, on an enlarged scale, of part of the system.
The main supply pipe, A, is connected at a to a service pipe, B, that is fur-
nished with faucets, C, at different points. D indicates two of the improved
expansion chambers, shown in my British Patent of December 31, 1898, above
referred to, and E indicates a modified form of expansion chamber.
In a system such as thus far described, there is liability of the water rising and
filling the expansion chambers, especially when the flow is constant, long con-
tinued and rapid. To overcome this objection I provide means for supplying an
additional quantity of air to the chambers. There are several ways in which
this may be accomplished.
At F I have shown by dotted lines a pump for forcing air into the main supply
pipe, A. This pump may be located at any point in the main, either at the
pumping station or remote therefrom, or it may be applied to the service pipes
of a building. Air forced into the pipe by the pump will travel with the water
toward the expansion chambers, and will float upwards and rise into them and
become compressed therein, and thus exclude the water.
The preferred means for supplying air to the chambers is, however, shown at G,
which is a contrivance adapted to automatically admit air when water is flowing
in the pipe. A vessel, g, is formed with an opening, g¹, provided with an internal

page_text: valve-seat fitting a valve, g³, carried by a float, g. The casing is connected to
the pipe, B, by a passage, g², opened and closed by a cock, 9. Lugs or rails, 96,
either on the float or on the bottom of the inside of the vessel prevent the float
from dropping too far so as to close the passage, g². Preferably the pipe, B, at
this point is a separate section provided with a nozzle, a, extending past the
passage, g², and into a sleeve, ¹, flared at opposite ends.
By this arrangement, when the cock, g³, is open and water is flowing in the
pipes, air will be drawn in past the valve, g³, through the opening, 92, and into
the service pipe. It will pass along the pipe with the water, and will rise in the
expansion chambers.
By thus supplying the chambers with an additional amount of air, I have
completely overcome the difficulties experienced in some cases with the use of the
invention covered by my patent before referred to.
The drawings merely illustrate one way of embodying my invention. The
expansion chambers should be located at such points as to meet the requirements
of each case, and the devices for admitting or supplying air to the system may
be varied in construction and location, according to circumstances.
While I, of course, prefer to use air for the expansion chambers, any other suit-
able gas may be substituted.
The modified form of expansion chamber shown at E is one which I preferably
employ for vertical pipes, the chamber having its mouth arranged in line, or sub-
stantially in line, with the direction of flow or pressure in the water pipe.
The vertical water pipe may be provided with any suitable number of expansion
chambers arranged at suitable distances apart. The most convenient way of applying
the expansion chambers to the vertical pipe is that illustrated in the drawing, in
which the expansion chamber, E, is shown as formed in a casting, H, provided with
couplings, h, for connecting its opposite ends to the water-pipe.
I arrange the chamber, E, in such manner that it shall be in line with the
direction of flow or pressure in the water-pipe indicated by the arrow, so that
when ice forms the pressure will be direct into the chamber and will not be
impeded by shoulders or the like.
The chamber, E, is air-tight and is closed except at its mouth, e, which is
arranged directly over the water pipe, and in line with the direction of flow or
pressure. Preferably the chamber is oblong, its major axis being vertical. The
chamber may be curved or concave at its upper end, e¹, and at its lower end the
outer wall of the chamber is curved at e² to gradually merge into the neck, e³,
which is coupled to the water-pipe. The particular form of the chamber is not,
however, absolutely essential. The inner wall, I, of the chamber terminates at i,
and outside of this wall is a passage, J, for the flow of water from the water-pipe
below the casting to the water pipe above it. It will be observed that this
chamber or passage, J, is deflected laterally around the chamber, E. It is of
sufficient area in cross-section to permit the flow of water freely in the usual way.
By making the casting containing the chambers, E and J, oblong, and arranging
them vertically, and by arranging the ends of the chamber, J, in the same vertical
line, I obtain a compact construction enabling water-pipes to be placed close
together and also obtain a good form of expansion chamber into which the ice may
pass as quickly as it is formed. It will be understood that the air in the cham-
ber, E, keeps the water at about the level indicated, but when ice forms the air
is compressed to make room in the chamber for the expanding ice.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what I
claim is;
1. A water-pipe provided with an expansion chamber to receive freezing water
or ice, and devices for supplying a gas, such as air, to the chamber.

page_text: or ice, and a device connected with the water-pipe for supplying air to the water-
pipe from which it in turn passes to the expansion chamber.
3. A water-pipe provided with an expansion chamber to receive freezing water
or ice, and means for admitting or forcing air into the water-pipe.
4. A water-pipe provided with an expansion chamber to receive freezing water
or ice, an air inlet port for admitting air to the water-pipe, a valve controlling
this port, and a nozzle in the pipe extending past the port.
5. A water-pipe provided with an expansion chamber to receive freezing water
or ice, a vessel communicating with the water-pipe, and having an air inlet, a
valve controlling the air-inlet, a float to which the valve is attached, and a nozzle
within the water-pipe extending past the passage between the water-pipe and the
valve-chamber.
6. A water-pipe a section of which is provided with a chamber open at both
ends for the passage of water, and having its ends in the same vertical line, and
another chamber for containing air and for receiving ice or freezing water and
having a mouth or opening in line, or substantially in line, with the direction of
flow or pressure in the water-pipe.
7. A water-pipe in which is interposed a casting provided with a vertically
arranged, air-containing chamber with a mouth at its lower end in line with the
direction of flow or pressure in the water-pipe, and a passage for water deflected
around the air-containing chamber, and having its ends arranged in the same
vertical line.
8. The combination of a water-pipe and an interposed, oblong casting provided
with an air-tight, vertical expansion chamber in line, or substantially in line,
with the direction of flow or pressure in the water-pipe, and having a deflected
passage around the chamber for the flow of water, the ends of which are arranged
in the same vertical line.
9. The water-pipe system, substantially as herein shown and described.
10. The expansion chamber for vertical pipes, substantially as herein shown and
described.