Note: Descriptions are shown in the official language in which they were submitted.
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The invention relates to pressurizing of a
vessel from a selected supply gas at high pressure where
the vessel is to be pressurized with precision predeter-
mined value somewhat above atmospheric pressure.
As a self-contained unit, the invention is
adaptable for use in remote locations where external
sources of power, such as electrical, mechanical, or bat-
tery power is unavailable or inconvenient. Moreover, the
invention is useful for gas pressure regulation under sta-
tic conditions, even for use with toxic or corrosive gases.
It is a principal object of the inventlon to
regulate with a self-contained system the pressure and ~:
kind of gas in a pressurized vessel, such as a pressurizing
tank, pressurized room, chamber, duct, or the like, where
the pressurizing gas is supplied from a pressurized source,
the pressure of which furnishes the only source of power
required for operation.
The above and other objects of the invention .
are met by a gas pressure regulation system for maintaining
a predetermined pressure of gas in a vessel comprising:
a supply of pressurized gas, a pressure reducing regulator
positioned downstream from the gas supply, the pressure ~;
reducing regulator including a connection thereon having
first and second outlets, a safety relief valve providing
a redundant safety relief in the event the reducing regu-
lator fail~, the safety relief valve being downstream from
the first outlet, a pressure gauge downstream from the
; safety relief valve, a first connecting line for supplying
the supply of pressurized gas to the pressure reducing
regulator, the safety relief valve, the pressure gauge
and to the pressurized vessel downstream from the pressure
gauge, the gas being supplied to the vessel at a pressure
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higher than the predetermined pressure into a first inlet
connection with the vessel, and a control means for sensing
the predetermined pressure in the vessel through a second
inlet connection with the vessel separate from the first
inlet connection, the control means comprising a gauge
regulator downstream from the second outlet from the re-
ducing regulator, a controlled leak means connected to an
outlet of the gauge regulator, a safety valve downstream
from the gauge regulator for providing redundant safety
relief should internal relief in the gauge regulator fail,
a second connecting line from the second outlet to the
gauge regulator, the safety valve and from the safety
valve to a pilot regulator for supplying control gas through
the pilot regulator, the pilot regulator positioned down-
stream from the safety valve and having adjustable flow
means for adjusting the flow therethrough into the second
inlet connection into the vessel, whereby the pressure of
control gas in the second connecting line is determined
by the gas pressure balance between the controlled leak
means and the pilot regulator, the control means further
including a,diaphragm regulator positioned between the
pressure gauge and the first inlet connection for control
of the rate of flow of gas in the first connecting line
to the inlet connection from the reducing pressure regu-
lator, and a gas adjusting line communicating between the
second connecting line and the diaphragm regulator where-
by the flow of supply gas to the first inlet connection
is controlled in response to the pressure of control gas
- in the second connecting line.
The invention will be further explained in
detail with reerence to the accompanying drawings in
which:
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Figure 1 is a schematic representation of a
precision gas pressure regulator of the present invention.
Figure 2 is a perspective view of the arrange-
ment of Figure 1 in a compact self-contained unit.
Figure 3 is a perspective view of the arrange-
ment of Figure 2 from the opposite side.
In Figure 1, supply gas is furnished from tank
10 at a supply gas pressure of typically up to about 1,000
Psig, connected through inlet line 12 to high pressure
reducing regulator 14, which has a built in internal re-
lief valve. Regulator 14 is preferably altered by drilling
and tapping a 1/4 inch NPT (national pipe thread) connec-
tion 42 in the body of regulator 14 to serve as a supply
pressure for gauge regulator 16 through connecting line
18. Pressure is reduced by reducing regulator 14 to
about 10 Psig in line 20, which is connected to safety re-
lief valve 22, ordinarily set to relieve pressure at about
15 Psig, thereby providing a redundant safety relief
should internal relief in reducing regulator 14 fail.
Relief valve 22 is connected by line 24 to pressure gauge
26, which is conveniently adapted to measure pressures
ranging from 0 to 30 Psig. Shut-off valve 28 is provided
to permit gauge 26 to be checked or changed.
Gas then flows through line 30 through dia-
phragm-type regulator 32, which is a spring to open dia-
phragm-type regulator altered by plugging its internal
pressure sensing port and providing an external pressure
connection from line 34. Gas from line 30 flows through
regulator 32 and into outlet line 36 and through opening
38 into vessel 40, diaphragm regulator 32 being held open
by the internal spring of the regulator. Accordingly, gas
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flows into vessel 40, which can be a tank, chamber, duct, or room which is
undergoing pressurization.
The supply pressure coming from connection 42 on reducing regulator
14 is piped through line 18 to inlet 44 of gauge regulator 16, which is a
1/4 inch NPT 0-5 Psig regulator having a built in filter, condensate trap,
and internal relief valve. Gauge regulator 16 is ordinarily set for 1.0
Psig outlet pressure. Connected to outlet 4~ of gauge regulator 16 is a
special 1/4 inch NPT pipe street tee 48. Inlet 50 of tee 48 is provided
with a small orifice plate 52, soldered in place. The hole comprising this
orifice can vary in diameter from a number 80 drill size up to a number 65
drill size, the exact diameter depending on several factors, such as the
speed of response needed for adjustment of the pressure in vessel 40, which
i8 determined in part by the volume of vessel 40. Further, the hole diameter
in orifice plate 52 depends on the size of diaphragm regulator 32, which
can vary from 3/4 inch NPT to 4 inch ~PT and is sized to fit the volume re-
quirements of the particular use intended. Small safety valve 54 is located
in branch 56 of tee 48. Safety valve 54 is ordinarily set for about 2.0 Psig
to provide redundant safety relief should internal relief in gauge regulator
16 fail.
The small volume of gas coming through tee 48 is piped through
lines 58 and 34 to the external pressure connection of diaphragm regulator
32, and is also piped through line 60 to the inlet side 62 of pilot regulator
66. Pilot regulator 66 is altered as follows:
Pilot regulator 66 is a diaphragm-type regulator installed in an
inverted position. A lead weight of approximately 2 ounces is attached to
the diaphragm assembly of pilot regulator 66. Since pilot regulator 66 is
installed inverted, this weight acts to create a downward force on the
entire diaphragm. The diaphragm and lead weight are opposed by a
lightweight adjustable spring, and thus when the spring is compressed,
a point of equilibrium is reached between the weighted diaphragm assembly
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and the opposing spring force. Further compression of this spring
therefore increases the pressure setting. Further, a slanting drain hole
is drilled through the body and diaphragm case of pilot regulator 66.
This hole is then counterbored to accept and "0" ring to seal between the
body and diaphragm case. Since pilot regulator 66 is installed inverted,
any condensate which might normally collect on the diaphragm surface or
within the diaphragm case is automatically drained through this hole to
the outlet of the regulator.
In some intended uses, vessel 40 may contain toxic, radioactive
or corrosive material which might back up in line 68 and affect the
operation of the system. In such instances, a small hole can be drilled
through the seat of regulator 66, preferably approximately about a number
75 drill size, to provide a constant flow or calibrated leak rate even
when pilot regulator 66 is closed. Thus, this constant gas flow provides
a purge to sweep toxic or corrosive gases from the sensing system.
The outlet side of pilot regulator 66 is the sensing connection
and is connected by sensing line 68 to vessel 40, which is the tank, duct,
chamber, or room undergoing pressurization. This connection 70 is separate -
from connection 38, and line 68 is constructed to avoid low spots, traps,
or seals. Line 68 is preferably sloped at least 1/2 inch per foot so as to
be self-draining.
It is apparent from Figures 2 and 3, showing an assembled unit
comprising each of the components identified in Figure 1, that the entire
sy~tem is characterized by a high degree of portability and because of its
self-contained nature can be easily and conveniently connected, moved, or
carried to a location of use. Inasmuch as an external source of electrical
or mechanical energy is unnecessary for operation of the apparatus, no con-
nections to a source of electrical power, battery, or mechanical drive is
needed. The incoming arrow shown in Figure 2 represents the inlet line 12
of Figure 1, and will be ordinarily connected to a source of gas lO, not
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shown in Figure 2 or in Figure 3. The arrow showing gas exiting the system
in Figures 2 and 3 represents flow of gas toward vessel 40 through connection
38.
It can be seen that a high degree of compactness and portability
results with use of the present invention, coupled with a high degree of
precision and safety in actual use.
The following examples illustrate the action of a complete system,
but it is not contemplated or intended to limit the generality of the inven-
tion thereby:
EXAMPLE I
In the system illustrated in Figures 1-3, as described herein,
the spring compression in pilot regulator 66 is adjusted to balance at a
pressure of a 0.5 inch water column by adjusting the balance between the
lightweight adjustable spring and lead weight acting on the diaphragm to
produce a balance point at a pressure of 0.5 inches of water. As described
above, the outlet of pilot regulator 66 enters vessel 40 at a separate con-
nection 70 from the connection 38 from outlet 36.
As the supply of gas from source 10 passes through the apparatus
in the manner described above, a 10 Psig flow of gas passes through dia-
2~ phragm regulator 32 into line 36 and into vessel 40, resulting in a build-up
or accumulation of pressure. This pressure increase is sensed through con-
nection 70 and line 68. As the pressure in vessel 40 approaches 0.5 inch
water column, pilot regulator 66, which is set for 0.5 inch water column
closes and when a pressure in vessel 40 of 0.5 inch water column is reachéd,
pilot regulator 66 shuts completely. At this point, build-up of pressure
coming through tee 48 begins. Inasmuch as no flow through line 60 is pos-
sible, the diaphragm of diaphragm regulator 32 begins to compress the spring
of diaphragm regulator 32 to initiate closing thereof. Final build-up of the
1.0 Psig pressure in line 34 locks the valve seat of diaphragm regulator 32
to completely shut off flow from line 30 to outlet line 36. As long as the
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pressure in vessel 40 is held to the 0.5 inch water column level, no flow
through line 36 into vessel 40 will occur.
EXAMPLE II
Whenever pressure within vessel 40 drops below the 0.5 inch water
column setting, this drop is sensed through line 68 to pilot regulator 66,
in response to which regulator 66 begins to open. Since the orifice area
within regulator 66 is in excess of the area of tee 48, the pressure within
lines 60, 58 and 34 drops to zero with respect to atmospheric pressure.
The spring in diaphragm regulator 32 opens diaphragm regulator 32 and allows
flow from line 30 through regulator 32 into line 36 until the pressure within
vessel 40 has again reached preset value and diaphragm regultor 32 is closed
in the manner described above for Example I.
Although the complete system of the present invention has been
described as an off-on device, the system has proportional or throttling
characteristics, even though the proportional band or throttling range is
narrow. The regulating system of the present invention does not exhibit
the droop characteristics inherent in most reducing regulators. Thus, if
the withdrawal of pressure from pressurized vessel 40 proceeds at a given
fixed rate, the regulating system of the present invention will attain an
equilibrium point of balance at which inlet flow through outlet line 36 is
equal to the outlet flow from vessel 40 and the pressure within vessel 40
is maintained at a preset pressure within a very close tolerance. For
example, with use of the present invention, the pressure within vessel 40
can be set as low as about 0.25 inch water column and as high as about 2
inch water column over atmospheric pressure, with control of the pressure
in vessel 40 within limits of about _ 0.02 inch water column.
