Improvements in Pneumatio Testing Apparatus.
Year: 1897

page_text: Improvements in Pneumatio Testing Apparatus.
I, ALFRED APPs, Scientific Instrument Maker, of 433, Strand, in the County of
|London, do hereby declare the nature of this invention to be as follows;-
-
This invention relates to apparatus for testing casks, drums, cans, boilers and
other receptacles by exhaustion or compression, so as to ascertain, whether they
are and will remain water-, air-, or steam-tight, and has for its object, to avoid
all unnecessary complications, such as separate tubular connections with a pressure
gauge.
For this purpose I employ a pump made of brass or other suitable material,
and of such a capacity, that a man can conveniently work it as an exhaust pump
antil a vacuum of about 3 lbs. per square inch, or until a corresponding degree
of compression above the atmospheric pressure has been produced. This permits
of the single stroke of the pump withdrawing about 100 cubic inches. of gas or
air or compressing by a similar.quantity. To obtain this double action, the valves
aro arranged at each end, as well as in the centre, so as to work either way in.
conjunction with inlet or outlet openings controlled by a key with passage through
a single tube to the vessel joined up at the end by a flexible or other tube, the
main attachment being previously made in the vessel to be examined. To avoid
damage, there are no exposed tubes outside the body of the pump, the communica-
tion being preferably through the piston fitted with double acting packing
appliances and through the compound pump frame.
To ensure very rapid action and freedom from damage, a caged-in double action
barometer gauge is fitted to the top of the pump, so that the operator can see at
each stroke exactly what exhaust or compression is produced, and in a few seconds
can test a large vessel. As a delicate gauge is always affected by change of
barometric pressure due to weather, the adjustment to zero is made before com-
mencing the test.
Dated this 2nd day of April 1897.
Improvements in Pneumatic Testing Apparatus.
I, ALFRED APPS, Scientific Instrument Maker, of 433, Strand, in the County of
London, do hereby declare the nature of this invention and in what manner the
Price 8d.1

page_text: same is to be performed, to be particularly described and ascertained in and by the
following statement:-
This invention relates to apparatus for testing casks, drums, cans, boilers and
other receptacles by exhaustion or compression, so as to ascertain, whether they
are and will remain water, air, or steam-tight, and has for its principal object,
to avoid all unnecessary complications, such as separate tubular connections with
a pressure gauge.
For this purpose I employ a pump made of brass or other suitable material
in the manner hereafter described and of such a capacity, that a man can con-
veniently work it as an exhaust pump, until a vacuum of about 3 lbs. per square
inch, or a corresponding degree of compression above the atmospheric pressure
has been produced. This permits of the single stroke of the pump withdrawing
about a hundred cubic inches of pas or air, or compressing by a similar quantity.
In the accompanying drawings:-
1
Fig. 1 is a vertical section of a testing apparatus embodying my invention,
the sectional plane of the upper half being, however, placed at right angles
to that of the lower half; Fig. 2 is a section along line y -y of Fig. 1; Fig. 3
is an underside view; Fig. 4 a plan showing the pressure gauge, Fig. 5 a horizontal
section through the controlling plugs or stopcocks, Figs. 6 and 7 show the ends of
the flexible pipe L, which connect the testing pump with the vessel M to be
tested.
A is the cylinder of the pump, B the piston, C the inlet valve, 1) the outlet
valve, E the intermediato valve mounted on the piston.
As shown, valves are arranged at both ends of the cylinder, and also on the
piston, which is perforated. The vessel to be tested is connected with the pump
by a flexible tube L (Figs. 6 and 7) attached at f to a small intermediate
chamber F, which communicates with the valve boxes of the pump through
passages f, c, and, controlled by three-way stop-cocks H, H., H₂, the passage c
leading to the valve C and the passage d to the valve D situated in a valve
box D'.
The intermediate stop-cock H₂ serves to cut off all communication between the
intermediate chamber and the interior of the pump. The stop-cocks H, and H,
are placed at right angles, so that, while one is open towards the chamber F, the
other is open towards the atmosphere, and vice versa, according as the pump is
to be used for exhaustion or for compression.
The pump cylinder A is surrounded at a short distance by a concentric jacket A',
so as to form an annular space, which communicates at one end with the valve
chamber of the valve D, and at the other end with the passage d.
On the pump is mounted in a convenient position a double-acting pressure
gange I adapted to indicate either vacuum or pressure, and connected with a thin
tube passing through the interior of the annular cylinder jacket and thence
directly to the intermediate chamber F, so as to indicate the pressure or vacuum
existing in the latter. The jacket thus serves to protect the tube i.
The suction valve C, discharge valve D, and intermediate valve E may be of
known construction, but the valve box of the valve D is preferably provided with
a tubular guard and with a lid, to facilitate access.
If it be desired, to ascertain whether the pipe or a section of the pipe connecting
the chamber F with the vessel M to be tested, has any leakage, the said vessel is
screwed off, the outer end of the pipe or of the section to be tested is temporarily
closed with an air-tight plug or disc and then the test applied by means of
the pump and pressure gauge. For applying the disc ', the tube L together with
the coupling nut L' must be screwed off the piece F, then the disc introduced
into the interior of the nut, and the latter, together with the tube L Borewed ou
again.
As a delicate gauge is affected by changes of atmospheric pressure due to the

page_text: weather, the adjustment to zero is made, before commencing the test, by means of
a key, which acts on the pressure gauge as the usual setting screw of an aneroid,
but has an air-tight packing.
If the stop-cocks H₁, H₂, Н, are placed as shown by Fig. 5, the pump will
act as follows:-
During the upstroke of the piston B provided with a handle the suction
valve C is open, and air flows from the atmosphere through the stop-cock H',
and passage into the cylinder A; the valve E is closed and the delivery valve 1)
open air will therefore flow from the upper end of the cylinder A through the
valve into the jacket surrounding the cylinder, and pass through the passage d
and stop-cock H into the intermediate chamber F and thence into the vessel,
which is to be tested by compression.
During the subsequent downstroke of the piston B, the valves C and D will
close, the valve E will open, and air flow from the lower part of the cylinder A
through the openings of the piston into the upper part.
If the stop-cocks H, and H, are turned 90°, the passage d will communicate
through the stop-cock H, with the atmosphere, while the passage e communicates
through the stop-cock I, with the passage and chamber F. The pump will
therefore draw air from the vessel connected with the chamber F, and deliver it
into the atmosphere; that is to say, it will act as an exhaust pump.
If the controlling stop-cock H, be turned 180°, it will close the passage fl
and cut off all communication between the interior of the pump and the vessel
to be tested.
The intermediate chamber F need not form a distinct compartment, but may
simply be part of the passage f leading from the stop-cock H₁ to the pipe joint f.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is--
1. The combination of a testing pump having an intermediate chamber between
the interior of the pump and the vessel to be tested, with a controlling stop-cock
adapted to shut off the said intermediate chamber from the pump, and a double-
acting pressure gauge communicating with the said chamber, substantially as
described.
2. The combination of a testing pump having an annular jacket and an inter-
mediate chamber between the interior of the pump and the vessel to be tested,
with a controlling stop-cock situated between the said chamber and the interior
of the pump, and a pressure gauge connected with the said chamber by a pipo
protected by the cylinder jacket, substantially as described.
3. In a testing apparatus of the type described, a connecting pipe or section
of pipe provided with a temporary plug or stop-dise for testing the said pipe or
pipe section, substantially as described.
4. A testing pump provided with a jacket communicating at one end with the
discharge valve box and at the other with an outlet passage provided with a
controlling stop-cock, substantially as described.
5. Pneumatic testing apparatus comprising in its construction a jucketed
cylinder. a discharge valve communicating with the jacket, controlling stop-
cocks, and a double-acting pressure gauge, the whole being arranged and adapted
to operate substantially as described.
Dis 1ot dow of Tonu 1898
FAIRFAX & WETTER,
Agents, 37 and 39, Essex Street, Strand, London,