Improvements in connection with Gauges for Indicating the Pressure of Compressed Gases in Closed Vessels.
Year: 1890

page_text: Date of Application, 13th Feb., 1890
Complete Specification. Left, 13th Nov., 1890-Accepted, 13th Dec., 1890
PROVISIONAL SPECIFICATION.
Improvements in connection with Gauges for Indicating the Pressure
of Compressed Gases in Closed Vessels.
I, WILLIAM MORTON JACKSON of The Manchester Oxygen Company, Great
Marlborongh Street, Manchester in the County of Lancaster Chemist do hereby declare
the nature of this invention to be as follows:--
My said invention has reference to gauges employed to ascertain the pressure
existing in closed vessels containing compressed gas such for example as oxygen,
hydrogen or other heating, illuminating, or otherwise useful gases as is well under-
stood. It is frequently necessary to test the pressure in such vessels and for this
purpose a gauge is attached to or mounted on the vessel and placed in communication
therewith. As is well known when gas or air is placed under pressure latent heat is
developed, the said heat becoming more sensible the higher the pressure is raised.
Therefore when a gauge is connected to a vessel containing gas under pressure and
the valve is suddenly opened, the air or other gas occupying the tube becomes
suddenly compressed and correspondingly heated to such a degree that if the mixture
in the tube is combustible, it is ignited and an explosion frequently occurs with the
result that the gauge tube or both gauge tube and gauge are often destroyed and the
operator is subjected to considerable danger. This risk of explosion is greatly
increased in the case of a gauge being used to test pressure in chambers containing
different gases.
For example if a gauge which has been used to test pressure in a
vessel containing hydrogen or coal gas or other olefiant gas, is afterwards used to
test a vessel containing compressed oxygen the mixture of hydrogen or coal gas and
air remaining in the gauge tube forms an explosive gas which when suddenly com-
pressed and heated by the after admission of the compressed oxygen from the chamber
to be tested, is extremely liable to explode and in the combination of oxygen with an
olefiant gas or with oil deposited in the tube the explosion is of a very violent
nature.
With the object of preventing such accidents, I introduce into the foot or other
part of the shank or connecting tail piece of the gauge a suitable check or diffusing
medium to prevent the too sudden passage of the gas from the chamber to the gauge
so that the pressure in the gauge rises gradually and the latent heat developed, has time
to pass into the atmosphere or to be absorbed by the material of the gauge tube or
gauge so that no considerable heat is developed in the gauge and the risk of
explosion is averted. It will of course he evident that the aforesaid checking means
might assume various forms, but in a form which I at present find and consider to be
useful screw or otherwise fix a seating or plug into the foot of the connecting shank
of the gauge. Through the centre of this plug I drill a fine hole and upon the plug
I lay a number of alternate discs or layers of copper wire gauze or perforated, metal
I then add another screwed
and felt cloth or other pervious textile or other material.
plug similarly drilled with a fine hole and compress the alternate discs or layers of
metal gauze and felt or other material between the two plugs.
When the connecting valve is opened the compressed gas passes through the
perforation in the first plug and then through the layers of material between the plugs,
finally passing through the base plug to the gauge tube. The aforesaid layers or
discs of metallic and other material retard the speed and pressure of the gas even
when the gas is suddenly turned full on from the cylinder but does not affect or
prevent the ultimate admission of the full pressure in the cylinder to the gauge so as
to give a true indication of the pressure. The number and area of the said retarding
discs are governed by circumstances. I do not however confine myself to the
particular checking means described as other forms might be employed; for example

page_text: I might use one or several perforations of sufficient fineness, or I might provide a
passage governed by a needle valve or a chamber packed with sponge, slag wool
asbestos or other material which would act as a drag or brake upon the pressure or
current of gas proceeding to the gauge and so prevent overheating of the gas or
mixture in the gauge tube and consequent explosion as bereinbefore set forth.
Dated this 12th day of February 1890
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.
COMPLETE SPECIFICATION.
Improvements in connection with Gauges for Indicating the Pressure
of Compressed Gases in Closed Vessels.
I WILLIAM MORTON JACKSON of The Manchester Oxgyen Company, Great Marl-
borough Street, Manchester in the County of Lancaster, Chemist, 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 and
accompanying drawings:-
:-
My said invention has reference to gauges employed to ascertain the pressure
existing in closed vessels containing compressed gas, such for example as oxygen,
hydrogen or other heating, illuminating or otherwise useful gases as is well under-
stood. It is frequently necessary to test the pressure in such vessels and for this
purpose a gauge is attached to or mounted on the vessel and placed in communication
therewith. As is well known when gas or air is placed under pressure latent heat is
developed or rather concentrated the said heat becoming more sensible the higher
and the more suddenly the pressure is raised. Therefore when a gauge is connected to a
vessel containing gas under pressure and the valve is suddenly opened, the air or
other gas occupying the tube becomes suddenly compressed and correspondingly
heated to such a degree that if the mixture in the tube is combustible or if by
accident any oily matter has been left in the tube it is ignited and an explosion
frequently occurs with the result that the gauge tube or both gauge tube and gauge
are often destroyed and the operator is subjected to considerable danger. This risk
of explosion is greatly increased in the case of a gauge being used to test pressure in
chambers containing different gases. For example if a gauge which has been used
to test pressure in a vessel containing hydrogen or coal gas or other olefiant gas, is
afterwards used to test a vessel containing compressed oxygen, the mixture of
hydrogen or coal gas and air remaining in the gauge tube forms an explosive gaseous
mixture which when suddenly compressed and heated by the after admission of the
compressed oxygen from the chamber to be tested, is extremely liable to explode and
in the combination of oxygen with an olefiant gas or with oil deposited in the tube
the explosion is of a very violent nature.
With the object of preventing such accidents I introduce into the foot or other part
of the shank or connecting tail piece of the gauge a suitable check or diffusing
medium to prevent the too sudden passage of the gas from the chamber to the gauge
so that the pressure in the gauge rises gradually and the latent heat developed by
the increase of pressure has time to pass into the atmosphere or to be absorbed by the
material of the gauge tube or gauge so that no considerable heat is developed in the
gauge and the risk of explosion is averted. It will of course be evident that the
aforesaid checking means might assume various forms but in the annexed sheet of
drawings I have illustrated the form which I have proved to be most efficient. Fig. 1
of the drawings is a view of a pressure gauge, part of the tail piece a being drawn
in section to show the application of my invention. The tail piece a is bored as
shown in the drawings so as to communicate with the gauge tube. The hole is screwed
for a certain distance from the foot and into this threaded part I screw or otherwise
fix a seating or plug b. Thorough the centre of this plug I drill a fine hole as
shown and next the plug I lay a number of alternate discs or layers c of copper wire

page_text: gauze or perforated metal, and felt, cloth or other pervious textile or other material.
I then insert another screwed plug d similarly drilled with a fine hole and compress
the said layers of metal gauze and felt or other material between the two plugs b and d.
By adjusting the compression of the layers the passage of the gas pressure can be
regulated to any required velocity. The two plugs and the packing between are
shown to a larger scale for the sake of clearness in Fig. 2. The top of one of the
plugs or d is shown at Fig. 3 with the sawgate for screwing them down into
position. When the stop valve between the compressed gas cylinder and the gauge
is opened the compressed gas passes through the perforation in the first plug d and
then through the layers. c of material between the plugs, finally passing through the
base plug to the gauge tube. The aforesaid layers c or discs of metallic and other
material retard the speed and pressure of the gas even when the gas is suddenly
turned full on from the compressed gas cylinder, but does not affect or prevent the
ultimate admission of the full pressure in the cylinder to the gauge so as to give a
true indication of the pressure. The number and area of the said retarding layers
or discs are governed by circumstances. I do not however confine myself to the
particular checking means described as other forms might be employed; for example
I might use one or several perforations of sufficient fineness, or I might provide a
passage governed by an adjustable needle valve as shown in Fig. 4 or a chamber
such as that illustrated at Figs. 1 and 2 packed with sponge, slag wool, asbestos or
other material which would act as a drag or brake upon the pressure or current of
gas preceeding to the gauge and so prevent overheating of the gas or mixture in
the gauge tube and consequent explosion as hereinbefore set forth. I have not
illustrated the mode of connecting the gauge to the compressed gas cylinder that
being common knowledge and not affecting my invention. Although I have in the
foregoing description and drawings referred to the pressure reducing or braking
means as incorporated with the gauge or a part thereof, I might make it as a
separate part and apply it at any point in the tubing or connections between the
compressed gas cylinder and the gauge.
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. As an adjunct to gauges used for indicating and testing the pressure of com-
pressed gases in closed vessels interposing compressed layers or packing of suitably
pervious material or materials in the conduit connecting the gauge to the compressed
gas cylinder so as to act as a diffusing medium or drag or brake upon the passage of
the gas and thus prevent the pressure in the gauge tube from rising too rapidly
with the objects and substantially as described and shown.
2. In a gauge used for indicating and testing the pressure of compressed gases in
closed vessels the adjustable needle valve e for the purposes and substantially as herein-
before described and as illustrated.
Dated this 19th day of November 1800.
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.