IMPROVEMENTS IN SAFETY-VALVE PLUGS FOR WATER HEATERS OR BOILERS."
Year: 1881

page_text: LETTERS PATENT to Alexander Morison Taylor, of Lenzie, in the County of
Dumbarton, North Britain, Engineer, for an Invention of "IMPROVEMENTS
IN SAFETY-VALVE PLUGS FOR WATER HEATERS OR BOILERS."
PROVISIONAL SPECIFICATION left by the said Alexander Morison Taylor
at the Office of the Commissioners of Patents on the 23rd April 1881.
ALEXANDER MORISON TAYLOR, of Lenzie, in the County of Dumbarton, North
Britain, Engineer. " IMPROVEMENTS IN SAFETY-VALVE PLUGS FOR WATER
HEATERS OR BOILERS."
This Invention has for its object the construction of simple, reliable, and
inexpensive safety-valve plugs for water heaters or boilers, an important application
of the Invention being for preventing the explosion of kitchen boilers through the
stoppage of the supply pipes by frost.
In carrying out the Invention, a plug of brass or other suitable metal is formed
with an external screw thread and can be screwed into a plain screw-tapped hole
made in the boiler shell. The plug is made with a passage through it, having an
internal shoulder to serve as a valve seat, and also with a guide eye connected to
it by arms or ribs, so as to project from the inner side of the plug. A disk-shaped
or mushroom-shaped valve made in one piece with or fixed on a central spindle, is
provided for closing the passage; and the spindle passes inwards through the guide
eye, and has a weight or spring applied to it on the inside to keep the valve closed
against the ordinary internal pressure, but allowing it to open whenever the internal
pressure becomes excessive from any cause. When the valve is loaded with a
weight, the plug must be fixed in the top or other horizontal surface; but when a
spring is used, the plug may be fixed in a horizontal, vertical, or inclined surface.
An ordinary helical spring may be used, such spring being strung on the spindle
and acting between the guide eye and a nut fixed on the inner end of the spindle.
With the construction described the spindle, the guide, and the loading appliance
are inside of the heater or boiler, and thus protected from accidental injury or
tampering. The valve may be made so as when closed to be flush with the outer
face of the plug; and in new boilers or heaters a recessed part may be formed to
receive the plug, so that it may be flush with the outer surface.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Morison Taylor in the Great Seal Patent Office on the
19th October 1881.
ALEXANDER MORISON TAYLOR, of Lenzie, in the County of Dumbarton, North
Britain, Engineer. "IMPROVEMENTS IN SAFETY-VALVE PLUGS FOR WATER
HEATERS OR BOILERS."
My said Invention has for its object the construction of simple, reliable, and
inexpensive safety-valve plugs for water heaters or boilers, an important application
of my Invention being for preventing the explosion of kitchen boilers through the
stoppage of the supply pipes by frost.
In carrying out my Invention, a plug of brass or other suitable metal is formed
with an external screw thread, and can be screwed into a plain screw-tapped hole
made in the boiler shell. The plug is made with a passage through it and with a
valve seat; and it is fitted with a valve having a spindle which extends into the
boiler. The valve is loaded by a spring or weight applied to the spindle and placed
inside of the boiler. When the valve is loaded by a directly applied weight, the
plug must be fixed in the top or other horizontal surface of the boiler; but when a
spring is used, the plug may be fixed in a horizontal, vertical, or inclined surface.
The valve may be made so as when closed to be flush or nearly so with the outer
face of the plug; and in new boilers or heaters a recessed part may be formed to
receive the plug so that it may be flush with the outer surface.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append a Sheet of explanatory Drawings,
to be hereinafter referred to and representing modifications and applications of my
improved safety-valve plug.
On the accompanying Sheet of Drawings Figure 1 is a plan and Figure 2 a
vertical section of a modification of my safety-valve plug, as it may be fitted to an
existing boiler. Figures 3 and 4 are a plan and a sectional elevation showing how
the safety-valve plug may be fitted to new boilers in a manner to have no parts
projecting beyond the general outer surface of the boiler. Figures 5 and 6 are
vertical sections showing my safety-valve plug as applied to kitchen boilers.
The plug A is formed with an external screw thread, and can be screwed into a
plain screw-tapped hole made in the boiler shell B. A flange or head which is six-
sided or otherwise shaped for the application of a screw-key, is formed on the plug
which is screwed into its place, so that the head forms a tight joint. The plug A
is made with a passage C through it, and with an internal shoulder or valve seat D,
and also with a guide eye E connected to it by arms or ribs, so as to project from
the inner side of the plug. A disk-shaped or mushroom-shaped valve F made in
one piece with or fixed on a central spindle G is provided for closing the passage C,
and the spindle G passes inwards through the guide eye E, and has a helical
spring H applied to it inside to keep the valve F closed against the ordinary internal
pressure, but allowing it to open whenever the internal pressure becomes excessive
from any cause. A nut I is screwed on the inner end of the valve spindle G, and
the spring H acts between it and the guide eye E. As shown in Figures 1 and 2,
the safety-valve plug A is fixed in a flat boiler shell B, and the head slightly
projects, but not to an extent likely to expose it to injury. It may however in
new boilers be fixed in a recess formed for it in the boiler shell, as, shown in
Figures 3 and 4, so as to have no part projecting beyond the general outer surface.
A weight such as is indicated by dotted lines in Figure 4 may be substituted for
the spring H when the plug can be fixed with the valve spindle in a vertical
position; but when the helical spring H is used the plug may be fixed in the top

page_text: of the boiler as shown in Figure 5, or in the front as shown in Figure 6, or in any
other convenient position.
With the construction described, the spindle G, the guide E, and the loading
appliance H, are inside of the boiler or heater, and thus protected from accidental
injury or tampering.
Having thus particularly described my said Invention, and the manner of
performing the same, I have to state that what I believe to be novel and original,
and claim as the Invention secured to me by and in terms of the hereinbefore
in part recited Letters Patent is,-
The construction and application of safety-valve plugs for water heaters or boilers,
substantially in the improved manner hereinbefore described.
In witness whereof, I, the said Alexander Morison Taylor, have hereunto set
my hand and seal, this Seventeenth day of October, in the year of our
Lord One thousand eight hundred and eighty-one.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
A. M. TAYLOR. (L.S.)