Im- PROVEMENTS IN SAFETY VALVES
Year: 1872

page_text: LETTERS PATENT to John Jordan and Alfred Paul, Engineers, of
Liverpool, in the County of Lancaster, for the Invention of "Im-
PROVEMENTS IN SAFETY VALVES."
Sealed the 11th February 1873, and dated the 13th December 1872.
PROVISIONAL SPECIFICATION left by the said John Jordan and
Alfred Paul at the Office of the Commissioners of Patents, with
their Petition, on the 13th December 1872.
We, JOHN JORDAN and ALFRED PAUL, Engineers, of Liverpool, in
the County of Lancaster, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN SAFETY VALVES," to be as follows:-
These improvements are designed for the purpose of causing safety
valves to lift a full distance, so that the steam boiler or boilers to which
such safety valves are fitted may be at once relieved by a full discharge
instead of as at present by a limited lift and discharge.
By these improvements the steam pressure in a boiler or boilers
cannot accumulate beyond the point at which the safety valve is set to
discharge, and this point reached the safety valve is caused to open full

page_text: bore, and the steam is at once let away down to any desired pressure at
which the valve closes. The use of ordinary safety valves does not
prevent the rapid rise of pressure, and fire doors have to be opened and
dampers closed to keep down the steam if the ordinary exit for steam
should happen to be shut.
In order to fully explain the nature of this Invention we would
observe that the ordinary rule used to find the area for safety valves is
to allow one square inch of area for two square feet of fire-grate area.
We find less than one-third of this rule area amply sufficient to
discharge all the steam that can be made upon the rule grate surface or
that forced firing can give off from the grate area. To accomplish the
full opening of the safety valve or valves we,-
Firstly. In the case of a single valve being used weight it to the
pressure to which the boiler is to be worked. Above the valve and
attached to it is a piston fitting with an easy fit in an open tapped
chamber. This chamber is perforated below the piston and above the
valve, so that when the valve lifts the steam escapes from the boiler into
the chamber, and thence through the perforations into the atmosphere
at or near the boiler pressure. The pressure of the steam in the chamber
then acts upon the under side of the piston, which is made rather
larger than the valve, and forces the valve and piston up against a stop,
thus furnishing a full discharge through the perforations in the chamber
and also through the upper edge of the chamber under the piston.
When the steam falls say five or more pounds below the blowing point
the valve at once shuts down and closes.
Secondly. We perforate the piston instead of perforating the chamber,
or we perforate the piston and the chamber in order that escape may be
had when the valve lifts, and that the valves may be adjusted at all
times when the steam is up.
Thirdly. We use two or more valves in combination, as follows, viz.,
we make one of them in the manner described above, and by means of
a cross head or lever attach the other safety valves of the common kind,
and which are made to lift by being in connection with the above-
described lifting valve, when the full opening of all the valves is secured
in the manner described above.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said John Jordan and Alfred Paul in the Great Seal
Patent Office on the 13th June 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JoHN
JORDAN and ALFRED PAUL, Engineers, of Liverpool, in the County of
Lancaster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of December, in the
year of our Lord One thousand eight hundred and seventy-two, in
the thirty-sixth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said John Jordan and Alfred.
Paul, Her special licence that we, the said John Jordan and Alfred
Paul, our executors, administrators, and assigns, or such others as
we, the said John Jordan and Alfred Paul, our executors, adminis-
trators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SAFETY
VALVES," upon the condition (amongst others) that we, the said John
Jordan and Alfred Paul, our executors or administrators, by an
instrument in writing under our, or one of our, or their, or
one of their hands and seals, should particularly describe and ascer-
tain the nature of the said Invention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after the
date of the said Letters Patent.
NOW KNOW YE, that we, the said John Jordan and Alfred Paul,
do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described
and ascertained in and by the following statement in writing, and on
reference being had to the accompanying Drawings, that is to say:-
These improvements are designed for causing safety valves to lift or
open a full or any desired distance above their seats, so that the steam
boiler or boilers to which they may be fitted may be at once relieved by a
full or clear discharge of steam instead of as at present by a limited lift
and discharge.

page_text: By these improvements the steam pressure in a boiler or boilers
cannot accumulate beyond the point at which the safety valve is set to
discharge, and this point reached the safety valve is caused to open full
bore, and the steam is at once let away down to any desired pressure.
The use of ordinary safety valves does not prevent the rapid rise of
pressure, and fire doors have to be opened and dampers closed to keep
down the steam if the ordinary exit for steam should happen to be
shut.
In order to fully explain the nature of our Invention we would
observe that the ordinary rule used to find the area for safety valves is
to allow one square inch of area for two square feet of fire-grate area.
We find less than one-third of this rule area amply sufficient to dis-
charge all the steam that can be made upon the rule grate surface or
that forced firing can give off from the grate area.
Such being the nature and object of our said Invention for "Im-
provements in Safety Valves' we will now proceed to describe more in
detail the manner in which the same is to be or may be performed or
carried into practical effect, and in order that the same may be
distinctly understood we have annexed hereunto one Sheet of Drawings
illustrative thereof, and have marked the same with figures and letters
of reference corresponding with those in the following explanation

page_text: without the latter; and Figure 8 reprosents an example of the improved
valve used as a lifter to one or more common safety valves.
g is the main thoroughfare for the steam from the boiler; a is the
safety valve; b is the piston either attached to or forming part of said
safety valve; c are guide snugs for valve and piston; d is the chamber
between valve face and piston into which chamber steam first escapes
when the pressure just overcomes the load on valve; e, openings in
chamber for partial escape of steam from chamber d; f, openings in
piston also for partial escape of steam from chamber d; i, spindle
carrying load on valve; no load is shewn, but the load may be applied in
the usual manner by either springs or dead weight; k, space outside
chamber d when valve is enclosed; is the eduction pipe from space k;
m is a lever by which our improved self-acting lifting safety valve
relieves the load upon common safety valves when so used; n is an
adjusting screw for self-acting valve; o is a tozzle between common.
valve a¹ and load lever.
The mode of operation is as follows:-When the pressure of steam in
the boiler acting through the main thoroughfare y upon the under side
of the valve overcomes the load, the valve lifts (the same as a common
safety valve) and the steam escapes into the chamber d, whence partial
escape is provided through the openings e and f. The partial escape
causes pressure to be exerted in the chamber d and upon the under side
of the piston.
The united effort of the boiler pressure exerted upon the under side of
the valve, and of the chamber pressure upon the under side of the
piston causes the valve and piston to lift until the piston rises above
the top of the chamber, where it remains until the free escape of steam
lowers the pressure in the boiler, when the load causes the valve and
piston to fall into its seat and shut. In the process of closing, the
piston again enters the chamber, thus closing the free escape of steam
over the top thereof. The openings e and ƒ then serve to allow the
diminishing volume of steam to escape as the valve closes.
Having now described the nature and object of our said Invention for
Improvements in Safety Valves," together with the manner in which
the same is to be or may be performed or carried into practical effect, we
would remark in conclusion that what we consider to be novel and original,
and therefore claim as the Invention secured to us by the herein-before

page_text: in part recited Letters Patent is, the use and construction of a self-acting
lifting safety valve, capable of opening to any desired extent by means
of a piston and chamber furnished with holes for the partial escape of
steam, substantially as described.
In witness whereof, I, the said Alfred Paul (on behalf of the
said John Jordan and for myself) have hereunto set my hand
and seal, this Tenth day of June, in the year of our Lord One
thousand eight hundred and seventy-three.