Note: Descriptions are shown in the official language in which they were submitted.
CA 02299145 2009-05-08
PRESSURE TESTING APPARATUS AND TESTING METHOD
FOR PROPANE TANK SYSTEMS
Field of the Invention
The present invention relates to propane tank systems and, more particularly,
to a testing assembly and testing method for enabling repair personnel such as
a
driver- serviceman to readily check for leakage of propane gas from such a
system.
Background of the Invention
Propane gas leaks can obviously cause serious problems. For example, fires
resulting from such leaks can cause both property damage and personal injury
including, in extreme cases, death. Thus, a very real need exists for an
approach in
testing for such leaks that will effectively protect the homeowner-users of
propane
gas. Such protection would also be of substantial benefit to the companies
that
serve such homeowner-users particularly in the area of reducing the spiraling
costs
of lawsuits involving the leakage of gas into the home of a customer from the
propane system. This leakage is often from appliances that have inadvertently
been
left on at the time of a gas
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outage in the propane tank. In any event, whatever the cause of such leakage,
it is
obviously very important to be able to readily determine when there is leakage
from the
system.
There are strict rules associated with the assembly and servicing of propane
systems. The current rules are set out in NFPA Pamphlet 58. Considering the
rules that
bear on the issues involved with the present invention, NFPA Pamphlet 58,
Section 3-
2.10 states that "After assembly, piping systems (including hose) shall be
tested and
proven free of leaks at not less than operating pressure." Section 4.2.1
states that
"Before gas is introduced into a system after being shut off, the entire
system shall be
inspected to determine that there are no open fittings or ends and all manual
valves at
outlets on equipment are closed and all unused valves at outlets are closed
and
plugged or capped." Section 4.2.2 states "Immediately after turning on the gas
the
piping system shall be tested to ascertain that no gas is escaping." In
addition, section
4.3.4 describes the proves for purging (emptying of air from) a system that
has been
opened and states "After the piping has been placed in operation, all
equipment shall be
purged and then placed in operation as necessary."
Section 4.1.4 of this pamphlet describes the methods of pressure testing and
states as follows: "(a) Test pressure shall be measured with a manometer or
with a
pressure measuring device designed and calibrated to read, record, or indicate
a
pressure loss due to leakage during the pressure test period. The source of
pressure
shall be isolated before the pressure tests are made. (b) The test pressure to
be used
shall be no less than 1 1/2 time the proposed maximum working pressure, but
not less
than 3 psig, irrespective of design pressure. Where the pressure exceeds 125
psig, the
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test pressure shall not exceed a value that produces a hoop stress in the
piping greater
than 50 percent of the specified minimum yield strength of the pipe. (c)
Systems for
undiluted liquefied petroleum gases shall withstand the pressure test in
accordance with
(b) above, or, for single-staged systems operating at a pressure of/2 psig or
less, shall
withstand a test pressure of 9.0 1/2 inch water column for a period of not
less than 10
minutes without showing any drop in pressure. If the source of pressure for
this test is a
liquefied petroleum gas container, the container service valve shall be
checked for
positive shutoff with leak detector solution prior to the test, or shall be
disconnected
from the system during the test. (d) Test duration shall be not less than 1/2
hour for each
500 cubic feet of pipe volume or fraction thereof. When testing a system
having a
volume less than 10 cubic feet or a system in a single-family dwelling, the
test duration
shall be permitted to be reduced to 10 minutes. Fora piping system having a
volume of
more than 24, 000 cubic feet, the duration of the test shall not be required
to exceed 24
hours." Finally, Section 4.1.2 (exception) states that "Fuel gas shall be
permitted to be
used in piping systems operating at pressures of 0.5 psig."
At present, there is no way for a driver-salesman or a service person,
hereinafter
referred to for convenience as a repairman or repair personnel, to check for
leakage as
described above without interrupting the gas piping, a process that is very
time
consuming. Further, this process introduces unwanted air into the system and
thus
requires such air to be purged.
There are, of course, many systems which use permanent valves and gauges for
determining and/or controlling the pressure in the system. Reference is made
in this
regard to U.S. Patents Nos. 2,923,312 (Wagner), 4,332,273 (Boyce) and
4,338,793
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(O'Hern, Jr.) relating to refrigeration systems and to U.S. Patent No.
4,702,754
(Blocker) relating to natural gas or propane delivery systems and U.S. Patent
No.
4,183,078 (Sorrell) relating to a combination shut-off and test-injection
valve. Briefly
considering some of these patents, the Wagner patent discloses a valve tool
for
charging and discharging refrigeration systems including a tee-adapter for
testing gas
pressures. The Boyce patent disclosed a leak-proof connector including a valve
of the
Schrader (or Schroeder) type while the O'Hern, Jr. patent discloses an adapter
for a
refrigeration system which also uses a normally closed Schrader valve. The
Blocker
patent discloses a test adapter which permits pressure tests to be carried out
on
delivery systems for fuel gas, i.e., propane or natural gas.
Reference is also made to U.S. Patent No. 5,070,962 (Peterson, Jr.) which
discloses a split valve test plug for use in a high pressure pipe line to
sense pressure or
temperature using a test probe and gauge. The plug valve includes a valve
housing
which is threaded into a tapped threaded opening in the pipe line.
Summary of the Invention
According to the present invention, an assembly kit and method are provided
which permit service or repair personnel to check a propane system for leaks
at the time
of introduction of propane into the system and which eliminates the need for
the purging
described above after the test. The service person is also assisted in
ascertaining
whether the system is actually out of gas, requiring interruption of service,
in spite of the
reading(s) provided by the tank gauge(s) since such gauges may be inoperative
or may
be giving false readings.
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In accordance with a first aspect of the invention, a method is provided for
use by
propane tank service personnel in detecting escaping gas in propane tank
systems
including a regulator and a tank service valve connected together by a
standard
connector, the method comprising the steps of: replacing the standard
connector with a
permanent valve and connector assembly including first and second end
connections
and a branch connection portion, a valve unit disposed in said branch
connection
portion and including a valve stem actuable to open said valve unit, the
replacing step
including connecting said first and second end connections to the tank service
valve
and the regulator, respectively; and using a separate pressure gauge assembly
individually assigned to tank service personnel and adapted to be carried by
said
personnel for testing the pressure in the propane tank, said pressure gauge
assembly
including a pressure gauge; a valve assembly connector including means for
actuating
the valve unit when the valve assembly connector is connected to the valve
assembly,
said testing of pressure comprising connecting the valve assembly connector of
the
pressure gauge assembly to the branch connection portion of the valve assembly
to
actuate the valve unit and thus provide an immediate reading of the tank
pressure by
said gauge, using the reading of tank pressure in determining whether the tank
is out of
propane gas, and thereafter taking one or the other of the following two steps
depending on the determining step: if the tank is determined to not be out of
propane
gas, introducing gas into the tank as needed; and if the tank is determined to
be out of
propane gas, turning the tank service valve off, pressurizing the tank,
turning the service
valve on, introducing gas into the system to pressurize the system, thereafter
turning
the tank service valve back off again so as to isolate the gas introduced into
the tank,
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and reading the gauge pressure to determine whether gas is escaping from the
propane
tank system. It will be appreciated that because each tank service person
carries his or
her own gauge assembly, a separate gauge is not necessary for each propane
tank
system and one gauge assembly only is needed by each service person.
In a preferred, advantageous embodiment, the gauge includes an indicating
needle and further comprises a pressure scale and an ambient temperature scale
calibrated relative to said pressure scale so that the position of the needle
that provides
a reading of gauge pressure on the pressure scale also provides a reading of
the
corresponding minimum ambient temperature on the ambient temperature scale,
and
the determining step for determining whether the tank is out of propane gas
includes
determining the actual ambient temperature and comparing the actual ambient
temperature with the reading of said corresponding minimum ambient
temperature.
According to a second aspect of the invention, a kit is provided for use in a
propane tank system for enabling detection of escaping gas by tank repair
personnel,
the tank system including a standard connector connecting a regulator to a
tank service
valve, and the kit comprising: a valve and connector assembly for connection
between
the regulator and the service valve in place of the standard connector, the
valve and
connector assembly comprising a connector including end connections for
connection to
the regulator and the service valve, respectively, a main connector portion
between the
said end connectors, and a branch connector portion connected at one end
thereof to
the main connection portion, a valve unit disposed in the branch connector
portion and
including a valve stem actuable to open a connection to the main connector
portion; and
a separate pressure gauge assembly adapted to be carried by tank repair
personnel
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and including a pressure gauge, and a mounting means, connected to the
pressure
gauge, for providing connection of the pressure gauge to the branch connector
portion
of the valve assembly, and for, when connected to said branch connector
portion,
providing actuation of the valve stem so that, in use with the tank service
valve open,
the pressure gauge provides a reading of the tank pressure and, in use with
the system
pressurized and the tank service valve closed, the gauge provides an
indication of the
presence of a leak or open line in the propane tank system.
The gauge preferably includes an indicating needle and further comprises
includes a pressure scale and an ambient temperature scale calibrated relative
to said
pressure scale so that the position of the needle that provides a reading of
gauge
pressure on the pressure scale also provides a reading of the corresponding
minimum
ambient temperature on the ambient temperature scale.
The valve unit advantageously comprises a Schrader valve (also referred to as
a
Schrader-Bridgeport valve). Further, the means disposed at the other end of
the hose
of the gauge assembly preferably includes a finger pressure operated screw-on
connector. The latter feature enables the gauge assembly to be connected to
the
system without the use of wrenches or the like.
Preferably, the main connector portion includes at least one flexible portion.
Advantageously, the at least one flexible portion comprises a pigtail section.
In one preferred embodiment, the branch connector portion is welded to the
main
portion. Advantageously, the main connector portion includes a pigtail section
and the
branch connector portion is welded to the pigtail section.
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In another preferred embodiment, the connector includes a straight pipe
connector and one of the end connectors comprises left-hand threading on the
straight
pipe connector for connection to the service valve.
In yet a further embodiment, the branch connector portion includes a quick
coupling valve unit and the mounting means of said pressure gauge assembly
includes
a cooperating quick coupling connector.
In accordance with yet another aspect of the invention, a kit is provided for
use in a
propane tank system for enabling detection of escaping gas by tank repair
personnel, the
tank system including a standard connector connecting a regulator to a tank
service valve,
and the kit comprising: a valve and connector assembly for connection between
the
regulator and the service valve in place of the standard connector, the valve
and connector
assembly comprising a connector including end connections for connection to
the
regulator and the service valve, respectively, a main connector portion
between the end
connectors and including an outlet hole therein along its length, and a branch
connector
portion connected at one end thereof to the main connector portion and
terminating in a
free end, the branch connector portion comprising a saddle valve unit directly
connected to
the main connector portion over the outlet hole and including a valve stem
actuable to
open a connection from the connector to the free end of the branch connector
portion, and
a separate pressure gauge assembly adapted to be carried by tank repair
personnel and
including a pressure gauge, and mounting means, affixed to the pressure gauge,
for
providing connection of the pressure gauge to said free end of the branch
connector
portion of the valve assembly, and for, when connected to said free end of the
branch
connector portion, providing actuation of the valve stem so that, in use with
the tank
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service valve open, the gauge provides a reading of the tank pressure and, in
use with the
system pressurized and the tank service valve closed, the gauge provides an
indication of
the presence of a leak or open line in the propane tank system.
Preferably, the saddle valve unit includes outwardly extending spaced legs
which fit
around the main connector portion and are welded or soldered to the main
connector
portion.
According to a still further aspect of the invention, a method is provided for
use by
propane tank service personnel in detecting escaping gas in a propane tank
system
including a regulator and a tank service valve connected together by a valve
and
connector assembly including first and second end connections connected to the
tank
service valve and the regulator, respectively, a branch connection portion,
and a valve unit
disposed in the branch connection portion and including a valve stem actuable
to open the
valve unit, the method comprising using a separate pressure gauge assembly
individually
assigned to tank service personnel and adapted to be carried by said personnel
for testing
the pressure in the propane tank, the pressure gauge assembly including a
pressure
gauge; a valve assembly connector including means for actuating the valve unit
when the
valve assembly connector is connected to the valve assembly, and the testing
of pressure
comprising connecting the valve assembly connector of the pressure gauge
assembly to
the branch connection portion of the valve and connector assembly to actuate
the valve
unit and thus provide an immediate reading of the tank pressure by said gauge,
using the
reading of tank pressure in determining whether the tank is out of propane
gas, and
thereafter taking one or the other of the following two steps depending on the
determining
step: if the tank is determined to not be out of propane gas, introducing gas
into the tank
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as needed; and if the tank is determined to be out of propane gas, turning the
tank service
valve off, pressurizing the tank, turning the service valve on, introducing
gas into the
system to pressurize the system, thereafter turning the tank service valve
back off again
so as to isolate the gas introduced into the tank, and reading the gauge
pressure to
determine whether gas is escaping from the propane tank system.
Preferably, the valve and connector assembly includes a main connection
portion
between the first and second end connections, an outlet hole is drilled into
the main
connector portion at an intermediate location therealong, and the valve unit
comprises a
saddle valve affixed to the main connector portion over the outlet hole.
In accordance with yet another important aspect of the invention, a kit is
provided
for use in a propane tank system for enabling detection of escaping gas by
tank repair
personnel, the tank system including a standard connector connecting a
regulator to a
tank service valve, and the kit comprising: a valve and connector assembly for
connection
between the regulator and the service valve in place of the standard
connector, said valve
and connector assembly comprising a connector including end connections for
connection
to the regulator and the service valve, respectively, a main connector portion
between said
end connectors, a branch connector portion connected at one end thereof to
said main
connector portion and terminating in a free end, and a monolithic manifold
block,
connected in said main connector portion between two sections thereof, for
connecting
said main connector portion to said branch connector portion, the manifold
block including
a through bore in which is received facing end portions of the two sections of
the main
connector portion and a further bore extending orthogonally to, and connected
to, the
through bore, the further bore including a drilled hole portion of smaller-
diameter than the
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remainder of the further bore located adjacent to, and in communication with,
the through
bore, the further bore receiving therein, and being connected to, a valve unit
including a
valve stem actuable to open a connection from the connector to the free end of
the branch
connector portion, and a separate pressure gauge assembly adapted to be
carried by tank
repair personnel and including a pressure gauge, and mounting means, affixed
to said
pressure gauge, for providing connection of said pressure gauge to the free
end of the
branch connector portion of the valve and connector assembly, and for, when
connected
to said free end of said branch connector portion, providing actuation of said
valve stem so
that, in use with the tank service valve open, the gauge provides a reading of
the tank
pressure and, in use with the system pressurized and the tank service valve
closed, the
gauge provides an indication of the presence of a leak or open line in the
propane tank
system.
According to yet another aspect of the invention, a kit is provided for use in
a
propane tank system for enabling detection of escaping gas by tank repair
personnel, the
tank system including a standard connector connecting a regulator to a tank
service valve,
and the kit comprising: a valve and connector assembly for connection between
the
regulator and the tank service valve, said valve and connector assembly
comprising first
and second end connectors for providing communication with the regulator and
the service
valve, respectively, and a monolithic manifold block, said manifold block
including a
through bore and at least one further bore extending orthogonally to, and
connected to,
said through bore, one of said bores including a drilled hole portion of
smaller diameter
than the remainder of said one bore located adjacent to, and in communication
with, the
other bores, said one bore receiving therein, and being connected to, a valve
unit including
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a valve stem actuable to open a connection to the bores of the manifold block,
these other
bores including a threaded end portion and the end connectors including
threaded end
portions adapted to be received in the threaded end portions of the other
bores, the kit
further comprising a separate pressure gauge assembly adapted to be carried by
tank
repair personnel and including a pressure gauge, and mounting means, affixed
to said
pressure gauge, for providing connection of the pressure gauge to the valve
unit such that,
when the gauge is connected to said valve unit, the valve stem is actuated so
that, in use
with the tank service valve open, the pressure gauge provides a reading of the
tank
pressure and, in use with system pressurized and the tank service valve
closed, the gauge
provides an indication of the presence of a leak or open line in the propane
tank system.
Preferably, the assembly further comprises a flow control valve unit, adapted
to be
connected, in use of the kit, between the tank service valve and the manifold
block, for,
when actuated, isolating the tank service valve.
In accordance with a further aspect of the invention, a connector assembly is
provided for direct or indirect connection to the tank service valve of a
propane tank
system, the connector unit comprising a unitary monolithic manifold connector
block
including a through bore having opposite threaded ends and at least one
further bore,
extending orthogonally to, and connected to, the through bore, the at least
one further bore
having a threaded end, and one of said bores including a drilled hole portion
of smaller
diameter than the remainder of the associated bore, the assembly further
comprising a
valve unit including a threaded end received in said one bore, and a first and
second
threaded connectors adapted to be received in two of said threaded ends.
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In an advantageous embodiment, a flow control valve having a threaded end is
connected to one of said threaded ends between said manifold block and an
associated
one of said connectors, the associated connector being adapted to be connected
to the
tank service valve and the flow control valve, when closed, shutting off the
connection
between the tank service valve and the manifold block.
The at least one further bore preferably comprises a further through bore
extending
orthogonally to the first mentioned through bore and having threaded opposite
ends.
Advantageously, a pressure bleed valve is connected to one of the threaded
ends.
According to a further aspect of the invention, a pressure gauge test device
is
provided for testing mobile pressure gauges used by driver and service
personnel for
propane tank systems, the device comprising: a unitary monolithic connector
block
including first and second orthogonal through bores therein providing four
connection
ports, a male connector connected to one of said ports, a female connector
connected to a
separate one of said ports, a pressure gauge permanently connected to a
further one of
said ports, and a valve unit connected to another one of said ports and
including a valve
stem, actuated responsive to connection to the valve unit of a pressure gauge
to be tested,
for, when actuated, opening a connection to the bores in the manifold block.
Other features and advantages of the invention will be set forth in, or
apparent
from, the following detailed description of the preferred embodiment of the
invention.
Brief Description of the Drawings
Figure 1 is an exploded front elevational view of a pressure testing kit or
assembly constructed in accordance with a preferred embodiment of the
invention;
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Figure 2, is a top plan view of a propane tank incorporating the testing
assembly
of Figure 1;
Figure 3 is a front elevational view of the gauge of Figure 1;
Figure 4 is an exploded front elevational view of another embodiment of the
kit of
Figure 1;
Figure 5 is an exploded front elevational view of yet another embodiment of
the
kit of Figure 1;
Figure 6 is an exploded front elevational view of a further embodiment of the
kit
of Figure 1;
Figure 7 is an exploded front elevational view of still another embodiment of
the
kit of Figure 1;
Figure 8 is an exploded front elevational view of yet another embodiment of a
part of the kit of Figure 1; and
Figure 9 is a front elevational view of the embodiment of Figure 8, as
assembled;
Figures 10, 11 and 12 are an end elevational view, a front elevational view
and a
top plan view, respectively, of still another embodiment of the invention; and
Figure 13 is a front elevational view of the embodiment of Figure 8, as
assembled with a valve unit and installed;
Figure 14 is a front elevational view of an alternative implementation of the
embodiment of Figures 10 to 12;
Figure 15 is a perspective view of a further implementation of the basic
embodiment shown in Figures 10 to 12;
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Figure 16 is an exploded side elevational view of an embodiment similar to
that
of Figure 15, as adapted to be connected to a tank service valve and including
an
optional flow control valve;
Figure 16(a) is a perspective view of the flow control valve of Figure 16; and
Figure 17 is a front elevational view of a pressure gauge test device in
accordance with yet another embodiment of the invention.
Description of the Preferred Embodiments
Referring to Figure 1, there is shown an exploded front elevational view of
the
propane tank leakage detection kit or assembly of the invention. The overall
assembly,
which is generally denoted 10, basically comprises a valve assembly 12 which
is
adapted to be installed on the tank and a pressure gauge assembly 14 is
carried by
repair or service personnel and, as explained in more detail below, is adapted
to be
connected in line in the tank system and used in cooperation with valve
assembly 12 to
provide an indication or measurement of the gas pressure within the tank.
Before considering the two assemblies 12 and 14 in more detail, reference is
made to Figure 3 which shows the assembly 10 about to be used to measure the
pressure with a propane tank 16 of a propane tank system generally denoted 18.
The
propane tank system 18 includes a tank valve 20 located at the top of tank 16
generally
centrally thereof, a flexible "pigtail" connector 22 which connects tank valve
20 to a
regulator 24 and an outlet connector 26 which connects regulator 24 to the
house
piping, i.e., the piping into the house at which the tank system 18 is used.
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It will be understood that tank valve 20, regulator 24 and connector 26 are
conventional, and that a conventional system would include a connection,
typically in
the form of a pigtail connector, between the tank valve and regulator.
However, in
accordance with a preferred embodiment of the present invention, the
conventional
connection between valve 20 and regulator 22 is replaced by a connector 22
which is
constituted by or incorporates a valve assembly 12 corresponding to that shown
in
Figure 1 and which cooperates with a pressure gauge assembly 14 which is shown
in
Figure 2 and which also corresponds to that shown in Figure 1.
Referring again to Figure 1, valve assembly 12 includes a tee connector 28
which includes a central branch forming a male flare connection 28a adapted to
receive
therein a valve unit or valve 30. Valve 30 is preferably a conventional
Schrader valve
such as the valves which are conventionally used in refrigeration systems.
Such a valve
is described in, for example, in U.S. Patent No. 4,338,793 to O'Hern, Jr.
referred to
above. The valve 30 includes a valve stem or operator 30a which controls
opening and
closing of the valve 30 in a conventional manner. A knurled valve cap 32 fits
over the
male connection 28a when the valve is not connected to gauge assembly 14. The
base
of tee connector 28 is fitted in line into a flexible connector 34 so that,
with valve 30
closed, a direct or through connection is provided thereby between tank valve
20 and
regulator 24. At opposite ends of flexible connector 34 are conventional end
connections 36 and 38 including male unions 36a and 38a. It is to be
understood that
apart form connection therein of a valve unit therein the flexible connection
34 and end
connections 36 and 38 are entirely conventional and themselves form no part of
the
invention. The elements are considered to be part of valve assembly 1-2
because, in
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accordance with a preferred embodiment of the invention, the entire existing
standard or
conventional connection between tank valve 20 and regulator 24 is replaced by
valve
assembly 22 rather than inserting a valve unit in the existing connection.
Further, the
end connections 36 and 38 (and particularly the latter) can take different
forms
depending on the nature of the existing connection in the propane system.
Turning now to the gauge assembly 14, this assembly includes a gauge 40 with a
main connector 40a, an intermediate connector element 42, and a hose 44 with a
first
female flare union 46 at the end thereof proximate to gauge 40 and a second
female
flare union 48 at the opposite end thereof. Union 48 includes an actuator pin
or member
(not specifically shown) which provides actuation of valve stem 30a and thus
opening of
valve unit 30 when union 48 is screwed on the male flare connection 28a of tee
connector 28.
The face of gauge 40 is shown in more detail in Figure 3. Gauge 40 is a
pressure
gauge and in the illustrated embodiment, a measurement band or scale 50
provided
around the outer periphery of the gauge indicates the measured gauge pressure
in
pounds per square inch, while an inner, concentric, part-circular measurement
band or
scale 52 provides an indication of the corresponding ambient temperature in
degrees F.
In the latter regard, the temperature scale 52 is calibrated to provide an
indication of the
minimum ambient temperature for the corresponding pressure reading so that, as
shown, for a measurement of 40 psi gauge the temperature should be no higher
than
about 20 F while for measurement of 50 psi gauge the temperature should not be
higher than roughly about 52 F. These pressure-temperature relationships have
been
previously determined for propane tanks and by incorporating the relationships
into
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gauge 40, a repairman, knowing the ambient temperature, is provided with a
direct
indication as to whether the tank 16 may be out of fluid. Thus, considering
the position
of the needle 54 of gauge 40 shown in Figure 3, the ambient temperature
corresponding
to the pressure reading (of about 75 psi) is about 48 F so that the actual
ambient
temperature is higher, the tank 18 is possibly out of liquid.
It is to be understood that the indication provide by gauge 40 essentially
concerns the rate of vaporization of the liquid so that when the ambient
temperature
reading corresponding to the gauge pressure is lower than the actual ambient
temperature, an indication is provided that the vaporization rate in the tank
16 is
insufficient. It will be appreciated that there can be more than one cause for
this so that
the tank may not actually be empty. For example, the situation may be one
wherein the
liquid in the tank is being used at a very high rate when the pressure
measurement is
made or one where the tank is too small and a larger tank is thus required. In
any event,
the pressure measurement and the corresponding calibrated value of the ambient
temperature as compared with the actual temperature alert the repairman to a
possible
problem, including the possibility that the tank is empty.
Considering the overall operation of the assembly 10 of Figures 1 to 3, to
install
the valve assembly 12, the repairman simply replaces the existing, typically
flexible
connection between tank valve 20 and regulator 24 with valve assembly 12. With
the
valve assembly in place, to make a pressure measurement, cap 32 is removed
from tee
section 28 and the end connector or hose 44 is screwed onto tee section 28 so
as to
actuate valve 30 and open a path to gauge 40. A reading is then taken to
determine
whether the tank is out of liquid. As discussed above, even if a pressure
reading is
18
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CA 02299145 2000-02-23
obtained, the repairman will be alerted to the possibility that the tank is
out of liquid if the
corresponding calibrated ambient temperature reading on scale 52 is less than
the
actual ambient temperature. Assuming that some filling of the tank 16 is
required, the
tank is pressurized and the tank valve 20 is closed. At this point, gauge 40
is checked
again to determine whether there is a leak. If gauge 40 provides a steady
reading, there
is no leak downstream thereof. On the other hand, if there is a significant
fall in pressure
and, in particular a fall in pressure within the limits of sections 54 and 58
of the NFPA
Pamphlet referred to above, it can be safely assumed that there is a leak in
the system
or an open appliance valve. The gas supply valve should then be left off, the
customer
notified and repairs made, as required.
Although the use of the gauge shown in Figure 1 is generally preferred because
of the ease of reading thereof, such a gauge may not be necessary in locations
such as
the sub-tropics where the temperature remains substantially constant during
the work
day and thus a conventional pressure gauge would be suitable. Further,
although this
would be more cumbersome, a chart or table showing vapor pressure of propane,
such
as that set forth below, can be used in combination with a conventional
pressure gauge
to relate temperature and pressure.
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TABLE 1
VAPOR PRESSURES OF PROPANE
130 F....... 257 psig 20 F.........40 psig
120 F....... 225 psig 10 F......... 31 psig
110 F....... 197 psig 0 F.........23 psig
100 F ....... 172 psig -5 F......... 20 psig
90 F.......149 psig -10 F......... 16 psig
80 F....... 128 psig -15 F......... 13 psig
70 F.......109 psig -20 F......... 10 psig
65 F....... 100 psig -25 F........... 8 psig
60 F.........92 psig -30 F........... 5 psig
50 F......... 77 psig -35 F........... 3 psig
40 F.........63 psig -40 F........... 1 psig
30 F......... 51 psig -44 F........... 0 psig
Referring to Figure 4, a first alternative embodiment of the invention is
shown. In
this embodiment, a straight pipe brass connector 60 is used to connect the
overall valve
and connector assembly 62 to the a conventional tank valve, indicated at 64.
Connector
60 includes conventional left-hand threading 60a for making this connection.
The
threading 60b at the other end of connector 60 is used to make a connection
with the
main body of a one piece female tee connector 66.
The other end of the main body of tee connector 66 is adapted to be connected
to the threaded end 68a of a pigtail connector 68 which includes a pigtail
portion 68a
and which connects to the regulator (not shown in Figure 4).
In this embodiment, a needle valve unit 70, including a valve control member
70a
and male threads 70b and 70c at opposite ends thereof, is connected to the
branch
connector portion of tee connector 66. The valve control member 70 controls
opening
and closing of the associated valve of valve unit 70, i.e., this is not
effected
automatically as in the previous embodiment.
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CA 02299145 2000-02-23
A pressure gauge 72 is screwed onto valve unit 70 when a pressure
measurement is to be made whereas a cap 74 can be screwed onto valve unit 70
at
other times. As set forth above, pressure gauge 72 can be a pressure gauge
such as
that shown in Figure 3 or can be a conventional (e.g., 300 psig) pressure
gauge for use
with a chart or table which corresponds to Table 1 above relating temperature
and
vapor pressure and which would be adapted to be carried by the service
personnel.
Referring to Figure 5, a further embodiment of the invention is shown. This
embodiment uses a number of components in common with the embodiment of Figure
4
and these components, viz., the straight pipe connector 60, the tee connector
66 and
the pigtail connector 68, have been given the same reference numerals. This
embodiment differs from that of Figure 4 in that the tee section also includes
a female,
liquid petroleum approved, quick coupling valve unit 76 which is adapted to be
screwed
by means of threading 76a onto the branch connection portion of tee connector
66.
Valve unit 76 is essentially conventional and includes an associated valve
(not shown in
Figure 5) which is actuated when a male connector element 78a of a
conventional male
quick coupling unit 78 is inserted into the female receptacle 76a of coupling
unit 76.
Screw threadings 78b enable male unit 78 to be connected to complementary
threadings 80a of a pressure gauge 80 which, again, can be the gauge of Figure
3 or a
more conventional gauge. Thus, a gauge reading can be provided by coupling
male unit
78 with the associated gauge 80 screwed thereon, to the female valve unit 76
in the
general manner of the embodiment of Figure 1.
Turning to Figure 6, yet another embodiment of the invention is shown. In this
embodiment, the connector portion of the valve and connector assembly
comprises
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CA 02299145 2000-02-23
connector element 82, which is similar to the connector element of the
straight pipe
connectors 60 of Figures 4 and 5 and which includes corresponding threading
82a for
connection to the tank valve (not shown in Figure 6), and a pigtail connector
84, which
is connected at its free end to the regulator (not shown). Further, instead of
providing a
separate tee connector as such, a tee or branch connection is provided by
welding a
Schrader valve unit 86 to the pigtail connector section 84. The core of the
Schrader
valve of unit 86 is indicated at 88 and valve unit 88 includes a conventional
free end
connector 88a adapted to be received in a swivel nut 90 with a depressing stem
(not
shown) for actuating the Schrader valve. A flange adapter 92, affixed to
swivel nut 90,
enables connection to a gauge 94 which, again, can be either of the two basic
types
discussed above.
Referring to Figure 7, still another embodiment of the invention is shown.
This
embodiment differs from those discussed above in that a direct hookup or
connection to
the regulator is provided and is particularly useful with systems employing
liquid
petroleum cylinders or bottles. A brass straight pipe connector 96 with
conventional left-
handed threading 96a for connection to the tank valve (not shown in Figure 7)
also
includes suitable threading 96b at the other end of the straight pipe section
96c of
connector 96 for providing the direct connection to the cylinder regulator
(not shown).
Similarly to the embodiment of Figure 6, a Schrader valve unit 98 is welded to
the
straight pipe section 96c and includes a valve core 100, and a swivel nut 102
for
actuating the Schrader valve is also provided. A flexible hose 104 connects
nut 102 to a
second female swivel nut 106 which differs from swivel nut 102 in that nut 106
does not
22
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CA 02299145 2000-02-23
include an actuating stem. A further connector 108, including a male flare
108a and a
female adapter 108b, is used to connect hose 106 to a suitable gauge 110.
Referring to Figures 8 and 9, there is shown yet another embodiment of the
invention. This embodiment is similar to that of Figures 6 and 7 in that a
valve
connection is again made directly to the pipe connection to the tank valve
(rather than
using a tee connector), but in this embodiment a "saddle" valve unit,
indicated at 110, is
used to make the direct connection. As shown in Figure 8, a hole 112 is
provided, e.g.,
by drilling, in a pipe connector 114. The latter may be a straight connector
or a pigtail
connector and includes an end connector 116 with conventional left hand
threading
116a. Ina specific exemplary implementation, connector 114 is either 1/4" or
3/8" by
12" copper pigtail tube.
The legs 11 Oa of saddle valve unit 110, which are skewed in Figure 8 for
purposes of illustration, fit around connector 114 and the saddle valve unit
110 is
soldered or welded directly onto connector 114 over the drilled hole 112. A
knurled end
cap or valve cap 118, generally corresponding to end cap 32, is connected to
the free
end of valve unit 110.
An advantage of the embodiment of Figures 8 and 9 over those of Figures 6 and
7 is that a stronger connection is provided between the valve assembly and the
connector piping. Valve unit 110 preferably incorporates a Schrader valve but
can
employ another type of valve as discussed above. It will be understood that a
meter
would also be part of the overall kit or assembly and would, in use, be
connected to the
valve 110 after the cap 118 was removed, as described above in connection with
the
other embodiments.
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CA 02299145 2000-02-23
Referring to Figures 10 to 13, still another preferred embodiment of the
invention
is shown. In this embodiment, a manifold block 120, best seen in Figures 10 to
12, is
used to make the valve connection to pipe connector to tank valve. As
illustrated, block
120 includes orthogonal bores 122 and 124, with a bore 124 extending
completely
through the block 120 between the sides thereof. Bore 124 comprises a first
diameter
portion 124a adjacent each of the sides which steps down to a second, smaller
diameter portion 124b between the side portions 124a. Bore 122 includes a
cylindrical
portion 122a, a tapered portion 122b and a small diameter portion 122c which
communicates with the central portion 124b of bore 124. The small diameter
portion
122c is the #54 orifice required by NFPA specifications or a smaller orifice.
Referring to Figure 13, the manifold block 120 is shown in the fully assembled
state thereof mounted between sections 126a and 126b of pigtail pipe connector
126
connected to an end connector 128 with conventional left hand threading 128a.
In
contrast the "saddle valve" embodiment of Figures 8 and 9, wherein the saddle
valve
unit 110 which includes the Schrader-Bridgeport housing LP valve core and end
cap
118, is attached to the pigtail 114 by soldering, brazing or the like and the
required small
hole 112 (the #54 orifice mentioned above or a smaller orifice) is drilled
into the tubing
through the center of the valve housing, attachment of the manifold block 120
involves a
different procedure. This procedure includes cutting the pigtail 126 (into
sections 126a
and 126b), deburring the cut end surfaces and the attaching the cut ends, by
welding,
brazing or the like, to the respective side bore portions 124a and 124b of
bore 124.
Further, a valve core housing 130 is then inserted into bore 122 and attached
to the
block 120, again by welding, brazing or the like. The very small diameter bore
or hole
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CA 02299145 2000-02-23
122c (#54 orifice or smaller) is drilled at this time. This procedure, i.e.,
later drilling of
hole 122c ensures that the welding or brazing operation will not result in
obstruction of
the hole 122c. Thereafter, the valve core (not shown in Figure 13) is inserted
into
housing 130 and an end cap 132 attached.
Figure 14 shows an alternative, presently preferred implementation of the
embodiment of Figures 10 to 13. In this embodiment, the countersunk
cylindrical portion
124b of bore 124 is eliminated and the side portions 124a are in direct
communication.
The facing ends of the side portions 124a are tapered or angled (at a 59
angle in a
specific, non-limiting example) as shown.
Referring to Figure 15, a further embodiment of the manifold block of the
invention
is shown. In contrast to specific implementation of the embodiments of Figures
10 to 14
that is shown in Figure 13, i.e., wherein the block 120 includes three
drilled, female
connections for making a soldered connection to appropriately sized copper
tubing (e.g.,
1/4 inch or 1/8 inch thick) with suitable connections at either end (e.g.,
M.POL and F.POL
or M.POL and M.NPT connections) and a pressure valve housing (e.g., a Schrader-
Bridgeport valve), and a drilled orifice of a suitable size (e.g., a #54
orifice or smaller) in
the pressure valve connection, the manifold block 134 includes three, or four,
as in the
embodiment illustrated in Figure 15, bores 136, 138, 140 and 142 with
corresponding
threaded (drilled and tapped) female connections 136a, 138a, 140a and 142a at
the ends
thereof. The bores 136, 138, 140 and 142 form a cross tee bore configuration,
generally
denoted 144, within block 134. A first, female connector 146 (e.g., a F.POL x
M.NPT
connector) is connected to bore 136 and a second, male connector 148 (e.g., a
M.POL x
M.NPT connector) is connected to threaded bore 138. An optional bleeder valve
150 is
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CA 02299145 2000-02-23
connected to optional threaded bore 140. A valve unit 152 (e.g., a
conventional Schrader
valve, i.e., a Schrader-Bridgeport valve) is connected to threaded bore 142.
Bore 142
includes a reduced diameter orifice 146 which is preferably a #54 orifice or
smaller. This
embodiment eliminates the pigtail associated with the block 120 of Figure 13
and enables
the block 134 to be directly connected in place in the system. Otherwise, the
block 134 is
similar to the block of Figures 11 to 14, apart from the optional bleeder
valve 150 and
optional associated bore 140. Bleeder valve 150 is a conventional bleeder
valve and
performs a standard pressure bleed function.
Referring to Figure 16, there is shown a further embodiment of the invention
related
to those of Figures 11 to 15. In Figure 16, a conventional tank service valve
156
(corresponding, e.g., to tank valve 20 of Figure 3) including an inlet
connection 156a
threadably receiving a male connector 158 (e.g., a M.POL x M.NPT connector)
generally
corresponding to connector 148 of Figure 15. In an exemplary, non-limiting
embodiment,
connector 158 is a M.POL (CGA 510) element with a 7/8 inch hex nut and 1/4
inch
M.NPT.
A three-port manifold block 160 (generally corresponding to block 134 of
Figure 15,
without bleeder valve bore 140) includes a first threaded port or bore 160a
which either
receives the threaded end 158a of connector 158 or, as illustrated receives
the threaded
end 162a of an optional, generally conventional flow control valve unit 162,
preferably in
the form of a shut-off ball valve, which is shown in more detail in Figure
16(a). In the
illustrated embodiment employing shut-off valve unit 162, flow control or shut-
off valve unit
162 receives the threaded end 162a of connector 158 and is used, through the
operation
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CA 02299145 2000-02-23
of control handle 162b (see Figure 16(a)), to shut off the connection to tank
service valve
156.
A valve unit 164 (e.g., a Schrader-Bridgeport valve corresponding to valve
unit 152
of Figure 15) is connected to a further bore or port 160b of block 160 which
includes a #54,
or smaller, orifice 160c.
A female connector 166 is screwed into a further port or bore 160a which is
formed
in block 160 and which is coextensive with bore 160a, i.e., is part of the
same through
bore.
The shut-off valve 162 can be used to isolate the tank service valve 156 so as
to
enable confirmation of leakage at valve 156. In addition, shut-off valve 162
can also be
used to provide a means for servicing the associated tank (e.g., corresponding
to tank 16
of Figure 3) without interrupting service. Such servicing could include valve
replacement,
painting of the tank, tank exchange and the like. To accomplish this without
interrupting
service, a further LP tank (not shown), carried, e.g., on the truck of the
service person,
would be connected to valve unit 164 of manifold block 160 to provide LP
service while, at
the same time, flow control valve 162 would be closed to disconnect the M.POL
connection provided by connector 158 to the tank service valve 156 and thus to
the tank
(not shown) being serviced. With connector 158 unscrewed from the tank service
valve
156, the corresponding tank can be removed for whatever servicing, repair or
replacement
that is necessary. It will be understood that, normally, service must be
interrupted and the
regulator, pigtail, and associated parts removed, to enable such things to be
done,
whereas the invention eliminates the need for such service interruption and
part removal.
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CA 02299145 2000-02-23
Referring to Figure 17, a further embodiment of the invention is shown, The
device
shown in Figure 17, which is generally denoted 170, is a gauge tester and is
based on the
manifold block embodiments described above. Gauge tester device 170 includes a
"cross
tee" manifold block 172 having four ports, as in the embodiment of Figure 15.
A male
connector 174 (e.g., a M.POL x 1/ inch (or larger or smaller) M.NPT or
soldered like
connector component) is connected to a first port, a female connector 176
(e.g., a F.POL x
'/. inch (or larger or smaller) M.NPT or soldered like connector component) is
connected to
a second port, a pressure valve housing 178 (e.g., a Schrader-Bridgeport
valve) 178 is
connected to a third port and a pressure gauge 180 (e.g., a 300 psi gauge) is
permanently
connected (e.g., soldered) to a fourth port. The gauge tester device 170 is
adapted to be
used at LP dealer service centers to test the accuracy in the pressure
readings provided
by the mobile gauges used by driver and service personnel. Such a test
pressure gauge
(not shown) would be connected to valve housing 178 for testing. Although a
four port
device is shown which is particularly adapted for use in "in service" or "in
use" applications,
a three port embodiment, wherein the female port (POL) is eliminated, is
preferred for
"isolated" testing.
Although the present invention has been described to specific exemplary
embodiments thereof, it will be understood by those skilled in the art that
variations and
modifications can be effected in these exemplary embodiments without departing
from the
scope and spirit of the invention.
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