U.S. patent number 3,693,652 [Application Number 05/016,387] was granted by the patent office on 1972-09-26 for liquefied gas tank distributor valve units.
This patent grant is currently assigned to Gurtner S.A.. Invention is credited to Jacques Iung.
United States Patent |
3,693,652 |
Iung |
September 26, 1972 |
**Please see images for:
( Certificate of Correction ) ** |
LIQUEFIED GAS TANK DISTRIBUTOR VALVE UNITS
Abstract
A distributor unit for liquefied gas tank, which comprises the
whole or part of a tank filling gauge, an output limiter, and
possibly a service member, a pressure-reducing device comprising a
body and a cover enclosing a resilient diaphragm responsive to the
expanded gas pressure and to the action of a compensator spring
co-acting with a control knob, and a valve member of the
pressure-reducing device actuated by said diaphragm, a pressure
indicator being also provided, this unit consisting of a vertical
grouping, into a single assembly, of said filling gauge, said
output limiter and said pressure reducing device or other service
member, said pressure indicator being incorporated in this
assembly.
Inventors: |
Iung; Jacques (Paris,
FR) |
Assignee: |
Gurtner S.A. (Paris,
FR)
|
Family
ID: |
21776861 |
Appl.
No.: |
05/016,387 |
Filed: |
March 4, 1970 |
Current U.S.
Class: |
137/557;
137/505.34; 137/517 |
Current CPC
Class: |
F16K
17/30 (20130101); Y10T 137/7818 (20150401); Y10T
137/8326 (20150401); Y10T 137/7869 (20150401) |
Current International
Class: |
F16K
17/30 (20060101); F16K 17/20 (20060101); F16k
017/30 () |
Field of
Search: |
;137/329.1,322,329.2,329.4,495,454.5,498,505.12,505.34,517,522,505.42,523,557
;285/322,373,420 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Nelson; M. Cary
Assistant Examiner: Matthews; David R.
Claims
I claim:
1. A distributor unit for a liquefied gas tank, which comprises a
substantially vertically arranged assembly comprising a tank
filling gauge, an output limiter, a pressure-reducing device
comprising a body and a cover, a resilient diaphragm mounted within
and between said body and cover responsive to gas pressure, a
compensator spring mounted in said cover to bias said diaphragm
against said gas pressure, control knob means mounted in said cover
to control the force exerted by said spring, a valve member of the
pressure-reducing device which is connected to be actuated by said
diaphragm and to control gas flow through said unit, and a pressure
indicator connected to indicate gas pressure in said unit.
2. A distributor unit according to claim 1, further comprising a
base member incorporating said output limiter and said filling
gauge therein, said base member being clamped to a lower portion of
the body of the pressure-reducing device with which said pressure
gauge is connected, said control knob means permitting relieving
said resilient diaphragm from the force of said compensator spring
and closing the valve member through the dual action of the
pressure of the gas contained in the tank and of a return
spring.
3. A distributor unit according to claim 2, wherein said control
knob means further comprises a rod cooperating with said
compensator spring to transmit the force of said compensator spring
to said resilient diaphragm, thus ensuring the cut-off valve
function by closing the valve member of said device.
4. A distributor unit according to claim 2, further comprising a
split collar integral with said base member for clamping said body
to said base member in the desired angular but relative co-axial
portion.
5. A distributor unit according to claim 2, wherein said control
knob means comprises an adjustment screw, a distance piece
associated with said adjustment screw and said compensator spring
to limit the free stroke of said spring so that the minimum
compression thereof is slightly inferior to the calibrated value of
said spring when said control knob means is screwed out and said
valve member of the pressure device is closed, and permit the
opening of said valve member when the calibrated value is attained
in the fully screwed-in position of said control knob means.
6. A distributor unit according to claim 5, wherein said body of
said pressure-reducing device has a transverse partition forming
therein a chamber having a frustoconical bottom wall, said chamber
being closed by said resilient diaphragm.
7. A distributor unit according to claim 6, further comprising at
least one perforation in said partition permitting communication
between said chamber and a gas outlet neck, a slit formed in said
frustoconical bottom wall leading to an orifice permitting passage
of a portion of the valve member.
8. A distributor unit according to claim 7, further comprising
apertures in one of said valve members to permit flow, by gravity,
of any liquid particles, resulting from a recondensation of the
gaseous phase, towards the underlying tank.
9. A distributor unit according to claim 5, further comprising a
ball interposed between the adjustment screw and the
distance-piece, said distance-piece comprising upper and lower cups
receiving the ends of said compensator spring.
10. A distributor unit according to claim 2, further comprising a
chamber in said cover so dimensioned that said compensator spring
can expand completely to prevent it from exerting any force against
said resilient diaphragm of the pressure-reducing device in the
fully unscrewed condition of said control knob means, the gas
output being cut-off by the closing of the valve member of said
pressure-reducing device.
11. A distributor unit according to claim 2, further comprising a
dipper tube of the filling gauge which tube extends through the
base member in which it can slide and abut against a lower portion
of the pressure-reducing device, a safety valve rigid with said
dipper tube and adapted to close the fluid passage through said
base member, said safety valve being normally held in its unseated
position by the lower portion of the pressure-reducing device when
the latter is screwed in said base member, a return spring
connected to said dipper tube urging said safety valve to its
seated position when said pressure-reducing device is screwed out,
the stroke of said safety valve and the expansion of said return
spring being so calculated that the closed position of said safety
valve is attained before said pressure-reducing device is screwed
out completely.
12. A distributor unit according to claim 11, wherein said safety
valve is secured to said dipper tube of the filling gauge
externally of said base member, so as to seal the lower end of said
base member in the closed-valve position.
13. A distributor unit according to claim 11, wherein said safety
valve is secured to that portion of said dipper tube of the filling
gauge which extends within a bore of said base member so as to seal
the fluid passage through said base member in the closed-valve
position.
14. A distributor unit according to claim 13, further comprising an
outlet neck of the pressure-reducing device and an output limiter
disposed within said neck.
15. A distributor unit according to claim 14, wherein said output
limiter comprises a square-sectioned member formed with a coaxial
bore and slidably engaging the bore of said outlet neck, a stop
socket secured to the outlet end of said neck, and a spring housed
within the bores of said square-sectioned member and of said stop
socket to urge them away from each other in the open position of
said limiter.
16. A distributor unit according to claim 15, wherein the diameter
of the bore of said stop socket is smaller than the length of the
side of said square-secioned member so as to close the fluid
passage therethrough when said member engages said stop socket in
case of overpressure.
17. A distributor unit according to claim 2, wherein said body
further comprises a screw-threaded and hollow lower extension to be
screwed directly to a tapped boss of said tank, so as to include
said filler gauge, inlet valve, tank pressure gauge and output
limiter into said body.
18. A distributor unit according to claim 17, further comprising an
abutment forming socket within said screw-threaded and hollow lower
extension of said body, upstream of the valve member, and formed
with a tapped portion adapted to be engaged by a screw-threaded
upper portion of a dipper tube of the filling gauge, with axial
orifices permitting passage of gas therethrough and with radial
ducts permitting communication between the upper end of said dipper
tube and the atmosphere.
19. A distributor unit according to claim 18, further comprising a
coil compression spring disposed within said valve member slidably
fitted in said lower hollow screw-threaded extension of said body
of the pressure-reducing device, said last-named spring reacting
against said abutment socket and acting upon said valve member in
the closing direction in conjunction with the gas pressure from the
tank.
20. A distributor unit according to claim 19, further comprising a
rod rigid with the central portion of the resilient diaphragm, the
lower end of said rod engaging the upper end of said inlet valve
freely in mutual sliding fit.
21. A distributor unit according to claim 1, further comprising a
base member incorporating said output limiter and filling gauge
therein and which comprises a pressure-gas outlet orifice whereby
said base member can be used as a top valve system and as an
expansion device, and a set screw for closing said orifice and
permitting any desired relative angular positioning and the mutual
locking of the pressure-reducing device and said base member.
Description
The present invention relates in general to distributor-valve units
equipping notably liquefied gas tanks.
Such units mounted as a rule on liquefied natural gas tanks are
well known in the art and comprise a number of components or
elements. These consist more particularly of :
A. supervision instruments, such as the pressure gauge and the
filling gauge or the liquid-level indicator ;
B. service apparatus, such as the gaseous-phase cut-off valve ;
C. safety devices, such as an output limiter.
In the known devices, a pressure-reducing device is mounted
downstream of this unit in order to reduce the inner pressure of
the tank to a value consistent with a normal use in the
gas-operated apparatus connected thereto.
It is the object of the present invention to provide a distributor
unit of the type broadly set forth hereinabove which permits
greatly simplifying the installation by assembling vertically in a
same body the above-mentioned instruments, apparatus and devices
together with the pressure-reducing device, this arrangement being
advantageous notably in that possible recondensations of the
gaseous-phase can flow down by gravity into the liquefied gas
tank.
This distributor unit comprising the whole or part of the following
elements : an output limiter ; a filling gauge for indicating the
liquid level in the tank ; a service member ; a pressure-reducing
device comprising a body and a cover enclosing a resilient
diaphragm responsive to the pressure of the expanded gas and also
to the action of a compensator spring co-acting with a control
handle, and a valve member responsive to said diaphragm ; and a
pressure gauge, is characterized in that it is obtained by
assembling into a single and same unit the filling gauge, the
output limiter and the pressure-reducing device, the pressure gauge
being incorporated in this unit.
According to a specific form of embodiment of the present
invention, a base member encloses the output limiter and the
filling or liquid-level gauge, and is clamped to the vertical body
of the pressure reducing device, the pressure gauge being fitted to
said vertical body, the control handle of the pressure-reducing
device being adapted on the other hand to isolate the resilient
diaphragm of said device from the force of said compensator spring
and to close the valve member of said pressure-reducing device
under the dual influence of the gas pressure in the tank and of a
return spring.
According to a first modification of the form of embodiment broadly
set forth in the preceding paragraph, this distributor unit is
characterized in that the base member of this unit, which encloses
the output limiter and the filling gauge, comprises a pressure-gas
outlet orifice whereby this base member can be used without any
modification in conjunction either with a ON-OFF valve system or
with an expansion device, a needle valve closing this orifice in
this last case and permitting the orientation in any desired
coaxial angular position and the locking of said pressure-reducing
device in the selected position.
According to a second modification of the distributor unit, the
latter is characterized by the fact that the knob or handle
controlling the pressure-reducing device of said unit comprises an
adjustment screw, and that a distance-piece is associated with said
screw and also with the compensator spring for limiting the free
stroke of this spring, so that the minimum compression of this
spring is slightly under the calibrated value thereof when the
control knob or handle is screwed out and the valve member of the
pressure-reducing device is closed, and that this valve member can
be opened when the spring calibrated value is in the fully screwed
in position of said control knob or handle.
According to a third modification of the form of embodiment of the
distributor unit, the latter is characterized in that the inner
chamber of the cover of said pressure-reducing device, which
encloses said compensator spring, is dimensioned to permit the
complete expansion of said spring so that it cannot exert any
pressure on said resilient diaphragm of the pressure reducing
device when the control knob or handle thereof is in its fully
screwed out position, and that the output is cut off as a
consequence of the closing of the valve member of said
pressure-reducing device.
According to further modifications of the form of embodiment of
this invention, which permits removing the reducing device from
said base member of the unit without having to drain the tank, the
distributor unit is characterized in that the dipper tube of the
filling or liquid level gauge or indicator extends through the body
of said base member in which it can slide for abutting against a
lower portion of the pressure-reducing device, said dipper tube
rigid with a safety valve being adapted to cut off the fluid
passage through said base member, said safety valve being on the
other hand held in its open position by the lower portion of said
pressure-reducing device when the latter is screwed in said base
member, a return spring associated with said dipper tube being
adapted to move said safety valve to its closed position when the
control member (knob or handle) of the pressure-reducing device is
unscrewed, the permissible stroke of said safety valve and of said
spring being so calculated that said valve is closed before the
aforesaid control member is fully unscrewed.
According to a further modification of the form of embodiment of
this invention, which permits an easy access to the component
elements of said pressure-reducing device and to the other service
members for checking or replacement purposes, without having to
remove the pressure-reducing device completely or drain the tank,
this distributor unit is characterized in that the body of said
pressure-reducing device is screwed directly in a tapped boss of
the tank by means of a hollow screw-threaded shank, and
incorporates the filling or liquid-level gauge, the tank pressure
gauge and the output limiter.
Other features characterizing this invention will appear as the
following description proceeds with reference to the attached
drawing illustrating diagrammatically by way of example typical
forms of embodiment of the distributor unit according to this
invention. In the drawing :
FIG. 1 is a sectional view of the distributor unit ;
FIG. 2 is a side-elevational view, with parts broken away, showing
more particularly liquefied the gas outlet of the unit of FIG. 1
;
FIG. 3 shows on a larger scale the distributor unit according to a
first modification of the form of embodiment shown in the preceding
Figures ; in this arrangement, an ON-OFF distributor valve is
substituted for the pressure-reducing device ;
FIG. 4 is an elevational view of the unit shown in FIG. 3 ;
FIG. 5 is a sectional view showing a second modification of the
form of embodiment of a distributor unit, wherein the control
system for opening and closing the pressure-reducing device is
modified with respect to that shown in FIG. 1 ;
FIG. 6 illustrates in section a distributor body according to a
third modification of the form of embodiment, with another
modification of the pressure-reducing device control system ;
FIG. 7 is a sectional view showing a modified form of embodiment of
the distributor unit of FIG. 5, which comprises an output limiter
incorporated in the base member and a safety valve disposed
externally of this base member ;
FIG. 8 illustrates in section a modification of a distributor unit
of the type illustrated in FIG. 7, with an output limiter on the
downstream pressure side within the outlet nozzle of the
pressure-reducing device, and a safety valve within the base member
;
FIG. 9 is a sectional view of the limiter, the section being taken
along the line IX--IX of FIG. 8, and
FIG. 10 is a sectional view showing a modified form of embodiment
of the distributor unit of FIG. 8, wherein the body of the
pressure-reducing device is secured directly to a gas tank but
without safety valve.
Reference will first be made to FIGS. 3 to 10 of the drawing, in
which the component elements corresponding to those of FIGS. 1 and
2 are designated by the same reference numerals, while the
equivalent but different elements are designated by the same
reference plus 100. In FIG. 10, the reference numerals differing
from those of the preceding Figures are numbered from 201 on.
In FIGS. 1 and 2, the distributor unit illustrated comprises a base
member 1 containing the output limiter 2 and a liquid-level or
filling gauge 3 operating by liquid tapping, a pressure-reducing
device 4 clamped in said base member 1 and a pressure gauge 5
screwed in the body 6 of said pressure-reducing device.
The base member 1 is made advantageously of brass and comprises a
screw-threaded lower end or extension 7 adapted to engage a
corresponding tapped hole of the liquid gas tank (not shown). This
lower end comprises a suitable bore 8 receiving the output limiter
2 consisting of a valve member 9 urged by a spring 10, in the open
position, against a perforated washer 11 associated with a filter
12 and retained by a spring ring 13. In case the output exceeds a
predetermined limit value, the pressure differential due to the
throttling passage A between the upstream and downstream sides
causes the valve member 9 to engage its seat 14, thus cutting off
the gas passage towards the expansion chamber. A narrow leak
passage is provided at B to enable the return of the valve member 9
urged by return spring 10 to its open position after the removal of
the cause of an abnormal output. The liquid-level or filling gauge
3 consists of a dipper tube extending into the underlying tank and
also through the valve member 9 so as to have its upper
screw-threaded end screwed in a tapped hole 15 formed in the upper
portion of said base member 1. A transverse passage 16 connects the
hole 15 and the gauge tube 3 to a lateral bore 17 formed in a boss
18 of said base member 1. A screw plug 19 provided with a sealing
plastic gasket 20 is adapted, by engaging a tapped portion of boss
18, to close the passage 16. A small orifice 21 connects the bore
17 to the surrounding atmosphere.
When filling the tank, the plug 19 is slightly unscrewed so that
liquefied gas rises from the tank along the dipper tube 3 when the
liquid level has attained the desired value, so as to flow out
through the small orifice 21. Thus, the gauge will indicate the
filling of the tank with liquefied gas by tapping liquid
therefrom.
The upper portion of base member 1 comprises a bore 22 having a
tapped upper portion communicating through passages 23 with the
aforesaid bore 8 of the screw-threaded lower end or extension 7. A
bored cylindrical portion 24 of the body 6 of pressure-reducing
device 4, which is externally screw-threaded, engages said bore 22
of base member 1. A resilient sealing O-ring 25 is provided in a
groove formed in said cylindrical portion 24. A split collar 26 is
formed at the upper portion of the aforesaid base member 1, so that
the body 6 of the pressure-reducing device 4 can be clamped thereto
in any desired angular position, about their common axis, by means
of screw 27.
The body 6 of pressure-reducing device 4 comprises an upstanding
collar portion 29 formed with inner screw-threads engaged by a
corresponding threaded portion of the skirt of a cover 28. A
resilient diaphragm 30 is clamped with the interposition of a
gasket 31 between the lower edge of cover 28 and an inner shoulder
of body 6, to constitute an expansion chamber 32 adapted to be
connected via an integral screw-threaded neck 33 to the pipe line
or hose leading to the gas-operated apparatus (not shown).
The resilient diaphragm 30 has its central portion connected
through a disc 34 and a core 35 provided with an integral rod 36 to
a valve member 37 normally urged by a return spring 38 to its
closed position to prevent the passage of gas towards chamber 32 by
engaging a seat 39 when said diaphragm is released from the action
of a main coil compression or compensator spring 40.
This compensator spring 40 is enclosed in the cover 28 between a
lower cup 41 bearing against the disc 34 of diaphragm 30 and an
upper cup 42 retained by an adjustment member 43 screwed in the
upper bored and tapped portion 44 of cover 28. By screwing or
unscrewing the adjustment member 43 the force of spring 40 which is
exerted against the diaphragm 30 can be adjusted in order to
provide the proper calibration of the downstream gas pressure.
A control knob or handle 45 is screwed in a tapped hole 46 formed
in the upper portion 44 of cover 28. A cylindrical rod 47 extends
on the one hand through a hollowed central portion 48 of said knob
and is a free fit in the adjustment member 43 and on the other hand
through the lower cup 41 of spring 40. The upper end of said rod 47
is screw-threaded, carries a washer 49 and is engaged by a nut 50
so as to lock this washer 49 against the inner shoulder 51 of said
control knob 45; a flat lateral face 52 prevents the relative
rotation of said rod 47 and knob 45. The lower portion of rod 47
carries another washer 53 retained by a spring ring 54. When the
control knob 45 is screwed in as shown in FIG. 1 the lower end of
rod 47 extends into the cup 41, without contacting same, and the
main coil compression spring 40 is adapted to exert its pressure
through the medium of this cup against the diaphragm 30. When the
control knob 45 is screwed out, the rod 47 rises and its washer 53
engages the cup 41 of spring 40 so as to compress the latter, thus
relieving the diaphragm 30, so that the latter be now responsive
only to the force of return spring 38 which, in conjunction with
the gas pressure from the tank, closes the valve member 37.
A pressure gauge 5 is screwed in a tapped bore 55 formed in the
body 6 of the pressure-reducing device. A duct 56 connects this
pressure gauge to the main bore 57 of the cylindrical portion 24 of
body 6. Thus, the pressure gauge 5 will indicate the pressure of
the gas flowing out from the tank.
Referring now to FIGS. 3 and 4, it will be seen that the
distributor unit comprises, in all the three modified forms of
embodiment to be described hereinafter, a base member 101
containing an output limiter 2 and a filling or liquid level gauge
3 of the liquid tapping type, which is closed by a plug 19. This
base member comprises on one side of its upper portion a
screw-threaded cylindrical boss 58 formed with a tapped bore 59
communicating with the axial bore 22 also tapped in said base
member. In a first modified form of embodiment a screw-threaded
portion 60 of the body 61 of a stop valve 62 having a valve member
63 is screwed in said base member 101. The stop valve 62 is
actuated by means of a handwheel or knob 145 secured by a screw 64
to the stop valve. An annular gasket 65 is disposed between the
base member 101 and the stop valve body 61 to seal the joint
therebetween.
The bore 59 constitutes the gas outlet of bore 22 when the stop
valve 62 is open ; the cylindrical boss 58 is provided for
connecting the device to a gas supply pipe or hose.
A pressure gauge 5 (FIG. 4) is provided for checking the liquefied
gas pressure in the tank and communicates with the bore 22 of base
member 101.
In a second modification of the form of embodiment of a distributor
unit according to this invention shown in FIG. 5, the base member
101 of the preceding construction, which incorporates the output
limiter 2 and the filling gauge 3, is also used. As in the example
shown in FIG. 1, the body 106 of a pressure-reducing device 4 is
screwed in a tapped portion of the base member bore 22. A set screw
66 engaging a tapped portion of the orifice 59 constituting the gas
outlet in the first modification shown in FIG. 3 permits setting
the body of the pressure-reducing device in the desired angular
position and also locking same in the selected position. An O-ring
25 seals the joint between the base member 101 and the
pressure-reducing device 4.
The body 106 comprises on one side a screw-threaded neck 33 for
connecting same to a gas supply pipe or hose, and on the other side
a tapped bore 55 engaged by the screw-threaded shank of the
pressure gauge 5, this bore 55 being connected through a passage
156 to the expansion chamber 32 communicating with the outlet neck
33. The body 106 has screwed therein a top cover 128 engaging a
collar 29 of said body, s shown. A control knob 45 is screwed in a
tapped bore 46 formed in the upper portion 144 of said cover.
The valve member 37 of the pressure-reducing device is adapted to
slide in the main bore 57 of body 106 and responsive to a coil
compression spring 138 having its lower end supported by a suitable
perforated washer 67 retained by a spring ring 68. The valve member
37 is connected via a rod 36 to the central portion of the
resilient diaphragm 30 interposed between the body 106 and the
cover 128. This rod 36 is adapted to slide freely in a bore 69
formed in a transverse partition 70 of the body 106 of the
pressure-reducing device, this partition 70 forming with the body
106 and the diaphragm 30 a chamber 71 having a frusto-conical
bottom. This chamber communicates on the one hand through an
oblique slit 72 formed in said partition 70 with chamber 32 and
leading on the one hand into the axial bore 69 and on the other
hand via a hole 73 into the gas outlet nozzle or neck 33. Another
function of this slit 72 is to permit in conjunction with bore 69
the gravity flow of liquid particles recondensed in chamber 71
towards the liquefied gas tank through the apertures of valve
member 37 and limiter 2.
The resilient diaphragm 30 is submitted to the force of a
high-flexibility compensator spring 40 enclosed in the cover 128
between the lower cup 41 bearing on a disc 34 rigid with the
central portion of diaphragm 30 and an upper cup 42. A
distance-piece 74 extending freely through these lower and upper
cups limits the free length of spring 40. To this end, this
distance-piece 74 is formed with a shoulder 75 bearing against the
upper cup 42 and provided at its lower end with a washer 53
retained by a spring ring 54. This washer is adapted to engage the
lower cup 41 when the spring 40 is allowed to expand.
The aforesaid distance-piece 74 is formed at its upper end with a
cavity 76 receiving ball 77. A screw 78 engaging a tapped hole 48
of control knob or wheel 45 and adapted to be locked in position by
a nut 50 extends freely through the cover 128 in a hole 79 and
bears with its lower or inner end against the ball 77. This screw
78 permits moving the upper cup 42 in the axial direction in order
to adjust the force of the compensator spring 40. The screw 78 is
adjusted in such a manner that when the compensator spring 40 is
fully unstressed or free and the hand knob or wheel 45 screwed out
completely, the diaphragm 30 is compressed to a minimum value lower
than the calibrated gauge value of the pressure-reducing device,
but relatively close to this value.
The gauge value and therefore the output value are obtained by
compressing the spring 40 by means of the control knob 45, i.e., by
screwing in this control knob ; the exact gauge value is obtained
when the knob 45 abuts against the shoulder 80 of cover 128 and
valve 37 is unseated, as shown in FIG. 5.
The output of the pressure-reducing device is cut off when the hand
knob 45 is screwed out ; a pin 81 rigid with the hand knob and
movable in a groove 82 formed in cover 128 is then in abutting
relationship with the upper edge of said groove. The spring 40 will
then allow the valve member 37 to move to its seated position, thus
cutting off the gas supply.
In a third modification of the form of embodiment of the
distributor unit according to this invention, which is illustrated
in FIG. 6, the only difference from the structure of FIG. 5 resides
in the control system for opening and closing the gas output from
the pressure-reducing device.
This control system comprises essentially a compensator spring 40a
having a free or unstressed length smaller than the room available
in cavity 83 of cover 128a. This spring 40a bears with its lower
end against the disc 34 rigid with the central portion of resilient
diaphragm 30, and with its upper end against a collar 84 formed on
a rod 85 rigid with the control knob 45 and secured thereto by
means of a nut 50.
When the control knob 45 is screwed home as shown in the left-hand
portion of FIG. 6, the spring 40a assumes its calibration value and
moves the value member 37 away from its seat 39 so as to open the
output at a pressure corresponding to the gauged value.
When the control knob is fully unscrewed as shown at 45' in the
right-hand half of FIG. 6, the spring is expanded and assumes the
position 40'a in which it does not exert any pressure on the
diaphragm 30. Thus, the valve member 37 urged by its spring 38 can
re-engage its seat 39, thus discontinuing the gas output.
Moreover, it is obvious that to all the intermediate positions of
control knob 45 there correspond different gauge values and
therefore different gas pressures ; under these conditions, it is
clear that the pressure-reducing device provides not only the ON
and OFF functions but also the "adjustable pressure" function.
Of course, the base member 101 of FIGS. 3 to 6 may also be used in
the distributor unit of FIGS. 1 and 2, or in any other equivalent
unit.
Referring to FIGS. 7 to 9 illustrating a modified form of
embodiment of the distributor unit shown in FIG. 5, it will be seen
that this assembly comprises a base member 101 incorporating the
output limiter 2 and a filling or liquid level gauge 3 of the
output-tapping type, closed by a plug 19. Screwed in this base
member 101 is the pressure-reducing device 4 having its body 106
locked in the desired position by means of a set screw 66 engaging
a tapped orifice 58 formed in said base member.
The body 106 comprises an outlet nozzle or neck 33 for connecting
same to a gas supply system, and a tapped bore 55 in which a
pressure gauge 5 is screwed. A cover 128a is fitted to the top of
the body 106 and a control knob or wheel 45 is screwed in the upper
portion of the cover.
The valve member 37 of pressure-reducing device 4, which is
connected through a rod 36 to the central portion of the resilient
diaphragm 30, is adapted to slide in a central bore 57 of said body
106 and responsive to a compression spring 38. The lower end of
this spring engages a suitable perforated washer 67 retained by a
spring ring 68 at the lower portion of bore 57.
The filling gauge 3 consists of a dipper tube 103 extending freely
through the valve member 9 of output limiter 2. This tube has a
narrower portion extending within the body of base member 101 so as
to form a chamber 86 connected to a discharge duct 16. A hole 87
formed through the narrower portion of tube 103 permits the flow of
liquefied gas during the level gauging operation.
Screwed on the upper end of tube 103 is a socket 88 engaging the
lower face of the washer 67 disposed at the lower portion of the
pressure-reducing device. The portion of tube 103 which is immersed
in the tank (not shown) is secured, for example by means of weld
spots 91, to a valve member 9.
When the control knob 45 of pressure-reducing device 4 is screwed
in toward base member 101, the valve 9 is in its open position,
i.e., externally of said base member. When the pressure-reducing
device is unscrewed, the return spring 90 keeps the socket 88 rigid
with the tube 103 in engagement with the washer 67, thus causing
the valve member 9 to move towards the lower end of base member
101. Before the pressure-reducing device is screwed out completely,
the valve member 9 is seated, thus closing completely the bore 8 of
base member 101. Under these conditions, the pressure-reducing
device can be removed as a unit, without having to drain the tank
beforehand.
In FIG. 8 illustrating a modification of the form of embodiment of
the distributor unit of FIG. 7, the dipper tube 103 of the liquid
gauge is rigid with the valve member 9, for example by means of
weld spots 91, this valve member acting in this case as a safety
valve instead of as an output limiter. The return spring 90 is
disposed between the valve 9 and a perforated washer 11 retained by
a spring ring 12 in the lower portion of bore 8 formed in base
member 101. This safety valve operates exactly as the one shown in
FIG. 7.
The output limiter 102 illustrated in FIGS. 8 and 9 is positioned
in this distributor unit on the downstream pressure side, in the
outlet neck 33 of pressure-reducing device 4. It comprises a
square-sectioned member 94 formed with a central bore 95 in which a
spring 96 is housed, as shown. A retaining socket 97 is screwed in
the tapped outer bore portion of the neck 33 to compress the spring
96, so that the latter constantly urges the square-sectioned member
94 towards the bottom of the neck, as shown. The bore diameter in
socket 97 is smaller than the length of each side of the square
section of member 94. When no fluid is present, the
square-sectioned member 94 slides within the neck 33 to engage in
closed position the aforesaid socket 97, thus closing the fluid
outlet orifice.
The distributor unit according to the last modified form of
embodiment of this invention comprises, as shown in FIG. 10, a
pressure-reducing device 204 having screwed in the upper collar
portion 29 of its body 206 a cover 128 carrying the control knob or
wheel 45, the intermediate portion comprising an expanded-gas
outlet neck 33 enclosing an output limiter 102. The body 206
comprises on the side opposite to this neck 33 a boss 202 having
screwed in its tapped bore 55 the shank of a pressure gauge 5
indicating the upstream gas pressure.
The lower portion of this body 206 is an integral hollow
screw-threaded extension 201 formed with a bore 208, its external
screw-threads 207 permitting screwing this unit directly in a
correspondingly tapped boss of the liquid-gas tank (not shown),
i.e., without using any intermediate base member.
The lower screw-threaded end 201 incorporates a filling gauge 3 for
the tank, which comprises a dipper tube 103 adapted to be
introduced into the inner space of the tank (not shown). The upper
screw-threaded end of tube 103 engages a tapped blind hole 203
formed in a coaxial abutment-forming socket 205. This socket 205
engages with its upper face a shoulder 209 of bore 208 and has its
lower face retained by a spring ring or washer 210. The lower face
of socket 205 comprises an annular groove 211 communicating through
a plurality of orifices 212 parallel to the socket axis with the
space overlying the upper face of this socket, to permit the free
passage of the fluid flowing from the tank.
The blind hole 203 communicates in turn through a radial passage
213 with a peripheral groove 214 registering with a radial orifice
215 formed through the wall of the lower portion 201 of the body
206, whereby the groove 214 communicates through a radial duct 216
with the bore 217 of a lateral neck 218 of said lower portion 201,
to permit the tapping of liquid gas when it is desired to ascertain
the liquid level in the tank. A plug 19 provided with a plastic
gasket 20 is screwed in a tapped portion of the bore of said neck
218 for sealing the radial duct 216 outside the level-determining
operations.
A packing of special synthetic resin, such as the one known under
the registered Trade Mark "LOCTITE", seals the pressure-reducing
device 204 in relation to the liquid gas.
Slidably fitted in the upper portion of bore 208 of the lower
extension 201 is a valve member 237 engaging a seat 39 under the
combined actions of the gas pressure and of the force of a coil
compression spring 222 housed in a bore 223 of said valve member,
this spring reacting against the upper face of the fixed socket
205. A plurality of peripheral flutes or like cavities 225 are
formed on said valve member to permit the gas flow when the valve
member is open. The bore 208 of the lower extension 201 of body 206
communicates via a lateral orifice 56 with the pressure gauge
5.
At its upper portion the valve member 237 terminates with a coaxial
cylindrical pin 224 extending into the expansion chamber 32 and
engaging a corresponding bore formed in the socket-forming lower
end of a guide rod 236 of hub 35 rigid with the central portion of
the resilient diaphragm 30 clamped between the body 206 and the
cover 128 of the pressure reducing device 204, and responsive to
the extended gas pressure. As in the case shown in FIG. 5, the
diaphragm 30 forms with the body 206 a funnel-shaped chamber 71
permitting the downward flow by gravity, towards the tank of any
recondensed gas particles through an oblique slit 72 formed through
the bottom of this chamber. The operative relationship between
diaphragm 30, compensator spring 40, the socket 43 and the control
knob or wheel 45 is also the same as in FIG. 5.
When the control knob or wheel 45 is screwed out it carries along
the axial rod 47 ; during the resulting upward movement of this rod
47 the lower spring cup 41 is also lifted, thus relieving the
diaphragm 30 of the action of compensator spring 40 and permitting
the closing movement of valve member 237 of the pressure-reducing
device under the dual action of the spring 222 and of the gas
pressure.
The same valve-closing procedure is observed when the cover 128 is
removed completely for replacing, for instance, the resilient
diaphragm 30. In this case, the force of spring 222 and the closing
movement of valve member 237 are so calculated that the latter
closes before the cover is screwed out completely. After having
removed the cover 128 completely, the operator can conveniently
remove the diaphragm 30 with its rod 236, the latter being easily
separated from the end 224 of valve member 237.
The operation described in the preceding paragraph can be carried
out without draining the tank beforehand, since the valve member
237 is urged against its seat 39 by the gas pressure of which the
output has been cut off.
It is thus clear that the pressure limiter 102 mounted in the
outlet neck 33 for the expanded gas as in the case of FIG. 8 has a
well-defined function and a very accurate action, since it operates
under regulated-pressure conditions.
This limiter may also be mounted in the fashion illustrated in FIG.
5, i.e., upstream of the socket 205 provided for securing the
dipper tube of the liquid level gauge.
Of course, it would not constitute a departure from the basic
principles of this invention to have other apparatus or members
added to, or removed from, the distributor units described and
illustrated herein, or to remove certain apparatus or members
therefrom, or to use apparatus or members of a type differring from
that described in the above examples, as will readily occur to
those conversant with the art.
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