provement in Apparatus for Controlling the Pressure in Fluid Tanks or Reservoirs especially Hot Water Tanks in Dwellings.
Year: 1896

page_text: Date of Application, 30th Sept., 1890
Complete Specification Left, 29th June, 1897-Accepted, 28th Aug., 1897
Complete Specification Left, 29th June, 1897-Accepted, 28th Aug., 1897
PROVISIONAL SPECIFICATION
Improvement in Apparatus for Controlling the Pressure in Fluid
Tanks or Reservoirs especially Hot Water Tanks in Dwellings.
I, ERIK AUGUST BOLINDER, of 32, Kungsgatan, Stockholm, Sweden, Director, do
hereby declare the nature of this invention to be as follows:-
This invention relates to .apparatus for controlling the pressure in fluid-tanks
especially hot water tanks in dwellings.
It is customary to obtain hot water from the cold water-supply in dwellings by
means of a system consisting of a boiler or water-heater so placed in a cooking-range
that it is heated by the same fire as is used for cooking, baking etc., and so connected
with the water-supply pipes and with a tank that the cold water in its passage
through the said boiler or heater is heated and collects in the said tank whence
it is distributed throughout the house by means of a special system of hot water
piping.
With this system of obtaining hot water there is danger from explosion or
bursting of the water tank if so much hot water collects in the same that steam is
generated, since the pressure may then rise to such a degree that the tank will
burst.
The object of this invention is to provide a safety-apparatus so connected with the
hot and cold water systems that, when the pressure in the hot water tank rises a
certain degree above the pressure in the cold water system, the hot water is drawn
off until the allowed difference of pressure is restored.
In the accompanying drawing Figure 1 shows a vertical sectional view of such
a safety apparatus and Fig. 2 shows a similar view of a somewhat modified
apparatus.
Referring to the drawing by letters, a represents a mouthpiece of a pipe connected
with the hot water tank. Said mouth-piece is open at one end and the object of the
same is to guide a valve b which movably surrounds the end of said mouth-piece and
closes against a packing e laid around the said mouth-piece. A piston d fits tightly
but movably in a part of the valve casing e which is so connected with the said
valve b that they both move together. The mouth-piece a is provided with openings
or holes so placed that when the valve b opens the hot water can run out into the
casing e and thence by an outlet f to the wastepipe or some other place to which it
is allowed to run off, and the cold water pipes g leading to the bottom of the hot
water tank are so connected with the valve casing e that the cold water pressure acts
on the free end of the piston d. The relation of the surface of the piston d, on
which the cold water pressure acts, and the surface of the valve b, on which the hot-
water pressure acts, is so adjusted that the valve b opens when the difference between
the pressure in the hot water tank and the pressure in the cold water pipe exceeds
the allowed limit.
The operation of the apparatus is obvious. When the pressure in the hot water
tank on account of the generation of steam or expansion of the hot water rises above
the allowed limit the pressure of the hot-water on the valve b overcomes the cold-

page_text: cold-water pressure on the free end of the piston d and the valve b and piston d move
together so that the valve opens and the hot water runs off by the outlet f until the
proper difference of pressure is restored.
In that part of the valve-casing which is in communication with the cold water
pipes, may be placed an independent valve which opens only when the pressure in
the hot-water tank is lower than the pressure in the cold water supply pipes but this
valve may, of course, be placed independently in the cold water pipes.
The above described valve may be applied for the same purpose to a vessel for
steam, gas or the like, in which case the valve is dispensed with and the pipe y is
connected with the steam or gas supply-pipe.
The modified apparatus shown in Fig. 2, differs from the one already described
in that the valve b instead of moving around the mouth-piece moves inside the
same.
The mouth-piece may in this case suitably consist of two pieces between which the
packing-ring c is tightly held.
The apparatus and its application may of course be modified in many ways, well
understood by any person skilled in the art to which it appertains, without departing
from this invention. Thus for instance, instead of the holes h, grooves may be made
in the surfaces of the mouth-piece and valve in such a way that they serve the same
purpose as the said holes h.
Dated this 29th day of September 1896.
Improvement in Apparatus for Controlling the Pressure in Fluid
Tanks or Reservoirs, especially Hot Water Tanks in Dwellings.
I, ERIK AUGUST BOLINDER, of 32 Kungsgatan, Stockholm, Sweden, Director, 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 improvements in apparatus for controlling the pressure
in tanks or reservoirs, especially hot water tanks in dwellings.
It is customary to obtain hot water from the cold water-supply in dwellings by
means of an attachment to a cooking-range of a water-heater, the so called water-
back, so placed in the cooking range that it is heated by the same fire as is used for
cooking, baking etc. and the lower part of which is connected with the coldwater
supply and bottom of a hot water tank, the so called boiler, and the upper part with
the top of said boiler and the system of hot water-piping in the house. The lower
part of the water-heater is sometimes connected only with the bottom of the tank
and the upper part of the water-heater with the middle of the boiler. In this
case the cold water pipe enters at the top and passes down nearly to the bottom of
the tank.
As is well known, the function of such an attachment is the following: The water
in the lower part of the tank enters the lower part of the water-heater, and in being
heated rises to the top of the heater, from whence it goes back to the tank and
collects in the upper part of the same, forcing the cold water in the lower part to
flow into the lower part of the water-heater to be heated in the same manner, so that
in a short time the tank will be full of hot water,

page_text: These hot water-heating attachments possess the disadvantage that, when the
water in the tank expands in being heated, the hot water is forced back into the
cold water pipes so that when cold water is wanted, it cannot be obtained until
the hot water is drawn off and that, when the water in the boiler becomes so hot that
steam is generated, there is danger from explosion or bursting of the tank if the hot
water is confined by the communication with the supply being cut off in one way or
other.
The object of this invention is to do away with the said disadvantages, and the
invention consists in providing a safety apparatus so constructed and connected with
the cold and hot water systems that it prevents the hot water from flowing back into
the cold water pipes but lets out the hot water or steam whenever the pressure in the
water heating attachment rises to a certain degree above the pressure in the cold
water pipes.
In the drawing left with the Provisional Specification Figure 1 shows a vertical
sectional view of such a safety apparatus and Fig. 2 shows a similar view of a some-
what modified apparatus.
Referring to the drawing by letters, a represents a mouthpiece of a pipe connected
with the upper part of the hot water tank. Said mouth-piece is open at one end and
the object of the same is to guide a valve b which movably surrounds the end of
said month-piece and closes against a packing e laid around the said mouth-piece. A
piston d fits tightly but movably in a xart i of the valve casing e, which piston is so
connected mechanically with the said valve 6 that they both move together. The
mouth-piece a is provided with openings or holes h, so placed that, when the valve b
opens, the hot water can run out into the casing e and thence by an outlet to the
waste pipe or some other place to which it is allowed to run off, and the cold water
pipes leading to the bottom of the hot water tank are so connected with the valve
casing e that the cold water pressure acts on the free end of the piston d. The
relation of the surface of the piston d, on which the cold water pressure acts, and
the surface of the valve b, on which the hotwater pressure acts, is so adjusted that
the valve 6 opens when the difference between the pressure in the hot water tank
and the pressure in the cold water pipe exceeds the allowed limit.
In that part of the valve-casing e which is a part of the connection between the
piston daud the tank, is placed an independent check-valve l. The object of the
said check-valve is to prevent the pressure in the tank from acting upon the piston d
or forcing the water back in the cold water supply pipes but to allow the cold water
to replace the hot water in the system, whenever the pressure in the hot water
systern is lowered by hot water being drawn. This valve need not necessarily be a
part of the safety apparatus, but may be placed in the cold water pipe somewhere
between the safety-apparatus and the hot water tank, outside the valve-casing.
The operation of the apparatus is now obvious. When the pressure in the hot
water boiler, on account of the generation of steam or expansion of the hot water
rises above the allowed limit, the pressure of the hot-water on the valve overcomes
the cold water pressure on the free end of the piston d and the said valve and piston
move together so that the valve opens and the hot water runs off by the outlet (pipe) f
until the proper difference of pressure is restored.
The above described safety-apparatus may be applied for the same purpose to a
vessel for storing steam, gas or the like, in which case the valve is dispensed with
and the pipe g is connected with the steam or gas supply-pipe.
The modified apparatus shown in Fig. 2 differs from the one already described in
that the valve & instead of moving around the mouth-piece moves inside the same.
The mouth-piece may in this case suitably consist of two pieces between which the
packing-ring c is tightly held.
The apparatus and its application may of course be modified in many ways, well
understood by any person skilled in the art to which it appertains, without departing
from this invention. Thus, for instance, instead of the holes h grooves may be made
in the surface of the mouth-piece and valve in such a way that they serve the same
purpose as said boles h

page_text: I am aware that safety apparatus have been used on hot water tanks, and I do not
claim this in its broadest sense.
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. A safety-apparatus for water-heating attachment for ranges, consisting of a
differential-valve or piston, movable in a cylindrical part of a valve-casing and on the
smaller end-surface of which the pressure of the boiler acts and on the larger end-
surface of which the supply pressure acts, said valve or piston being so placed in the
said casing as to normally cover an outlet to the drain, except when the pressure on
the small end-surface of the piston is able to overcome the pressure on the large end
of the same, when the piston will move so as to place the said boiler in communica-
tion with the said drain outlet by uncovering the latter, substantially as and for the
purpose set forth.
2. In a safety-apparatus for water heating attachment for ranges, the combination
of a hollow valve inovable in a cylindrical part of a valve-casing and with one end
normally engaging with a valve-seat, a mouthpiece serving as a guide for the said
valve, a piston moving in the said cylindrical part of the valve-casing and
mechanically connected with the other end of said valve so as to move with the same,
an outlet from said cylindrical part of the valve casing between the said valve-seat
and piston, said valve being in communication with the upper part of the boiler
and the piston being in direct communication with the cold water supply pipe, and
through a check valve (which prevents the water from flowing back from the boiler)
in communication with the lower part of the boiler, substantially as and for the
purpose set forth.
Dated this 28th day of June 1897.
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62 Saint Vincent Street, Glasgow, Agents for the Applicant.