An Improved Safety-valve for Prevention of Kitchen Boiler Explosions.
Year: 1896

page_text: Date of Application, 17th Jan., 1896
Complete Specification Left, 14th Oct., 1896-Accepted, 5th Dec., 1896
An Improved Safety-valve for Prevention of Kitchen Boiler
Explosions.
ALEXANDER MCFARLANE and GEORGE WHITFIELD Rivet Manufacturers
Dunston on Tyne Co. Durham do hereby declare the nature of this invention to
be as follows:-
An inverted gun-metal valve, with spindle passing through a stuffing box, with
a spiral spring on top is attached to the boiler at front of kitchen range so as to be
under constant observation. The spring is set with just sufficient power above
feed cistern pressure to keep valve closed, any over-pressure instantly overcomes
the spring and allows the over-pressure to blow through the valve, and valve closes
again when pressure is relieved.
It can also be tested at any time to try if in proper order by simply pressing a
button attached to spindle. Further in case of pipes being frozen and any undue
pressure getting up in boiler it is at once blown out through valve and gives timely
warning.
Dated this 16th day of January 1896
ALEX. MCFARLANE.
GEORGE WHITFIELD.
An Improved Safety-valve for Prevention of Kitchen Boiler
Explosions.
We, ALEXANDER MCFARLANE, and GEORGE WHITFIELD, both of Dunston-
on-Tyne, in the County of Durham, Rivet Manufacturers, 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 consists in an inverted valve, that is to say a valve which is below
its seating and is held upwards against its seat, the spindle of which passes through
a stuffing box and carries above the latter a spiral spring tending to lift the valve
and hold it against its seat. This device is attached to the boiler or to a pipe in
connection therewith usually at the front of kitchen range so as to be under constant
observation, the spring is intended to be set with just sufficient power above feed
cistern pressure to keep the valve closed. Any over pressure instantly overcomes
the spring and allows outlet past the valve, and the valve closes again when the
pressure is relieved.
The valve can also be tested at any time to try if it is in proper order by simply
pressing down the spindle.
Suitable nuts or other means are provided for adjusting the spring and
regulating the pressure of the valve against its seat. The upper surface of the
valve is in communication with the boiler, therefore the pressure on the under side

page_text: of the valve due to the spring must be sufficient to keep the valve closed against
that of the boiler under ordinary conditions. Should the pressure in the boiler
rise from any cause above the normal pressure the spring will be overcome and the
valve will open thus giving relief. If the device is connected to the boiler below
the water level, by pressing the end of the spindle the valve can be used as a
draw off tap, since the water will then run out below through a suitable nozzle or
pipe as long as the spindle is depressed. The valve may be of any suitable
form and the spindle may be elongated through the valve and guided if thought
necessary.
Such a valve is shown in the annexed drawing in vertical section, A is the
spindle, B the valve, C the valve seating, D the casing, E a branch pipe in
connection with boiler, F the gland, G checknut, and H the adjusting nut or cap
for the gland F, J is the spring, K adjusting nut or button for the spring, La
checknut therefor, M shows the casing constructed to serve as a guide for the
spindle, N is the draw off pipe.
The pressure of valve B against its seating C due to compression of the
spring J must be sufficient to keep the valve closed against pressure in E on the
top of the valve in ordinary circumstances. If the pressure in E should from any
cause exceed this then the valve B will be opened and the pressure relieved. By
pressing down the spindle A it may be ascertained if the device is in order and
water may be drawn off by pipe N.
Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The combination of a spindle partly in a valve casing and partly outside with an
inverted valve on the part in the casing and with a spring on the part out of the
casing tending to keep the valve closed against its seat, and with means of its
adjustment substantially as described.
Dated this 14th day of October 1896.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, London, Agents for Applicants.