Title of Invention

A DEVICE FOR LEAKAGE DETECTION IN A SELF-CLOSING VALVE OF AN LPG CYLINDER

Abstract A device for leak detection in a self-closing valve of an LPG cylinder, the LPG cylinder having LPG in liquid form inside the cylinder, the self-closing valve of the cylinder having plurality of sealing means and when pressed through its spindle, emits vapourised LPG via a regulator to the stove, characterized in that the device comprising atteast two individually consecutively applicable leakage encapsuled means disposed in an enclosure for leakage detection through said self-closing valve, the first leak detection means (1) comprising a tube (5) having a top cap (3) releasably fixed at a top end of the rube (5); a nozzle (9) attached to the tube (5) at an opposite end; a top inner cap (4) interposed at an upper end of the rube being pressably connected to said top cap (3); a sleeve (6) radially inwardly disposed at a lower end of the tube (5) being press fitted to said nozzle (9); and a capillary tube (7) extending upwardly being flowably connected to said nolzsle (9), the second leak detection means (2) comprising an open-ended tube (12) having a top cap (11) and a nozzle (15) being pressably fixable at a top end and at a bottom and thereto, a float (13) provided inside said open-ended rube (12) being vertically displaceable under the pressure of LPG when leaking through said self-closing valve of the LPG cylinder.
Full Text

FIELD OF INVENTION
The invention relates to a device for leakage detection in a self-closing valve
of an LPG cylinder.
BACKGROUND OF THE INVENTION
Every LPG Cylinder is provided with a Self Closing Valve (SC valve) on it.
This valve will normally be in close condition and only when the spindle of
the valve is pressed, LPQ inside the cylinder, which is in liquid form
vapourises and passes through the valve into the regulator and further to the
stove.
The SC Valve has two in-built sealing means, to arrest any leak into the
atmosphere. The two sealing means are facilitated by:
L Spindle Gasket
2. Joint packing (or) O-Ring
Both the said sealing means comprises moulded Nitrile rubber components.
Item No. 1. is I-Stage sealing, positioned on the spindle of the valve, which
protects any leak from the Valve, such type of leakage being called Valve Pin
Leak.
Item no. 2 is Il-Stage sealing, which prevents any leakage of the valve pin
leak and normal gas flow into atmosphere. This is operational when the
regulator or the safety cap is fixed on to the SC Valve.
However, over a period of usage, both the sealing means may get worn off
and dirt accumulation may occur in the item no. 1, which may lead to
leakage.
All cylinders are checked for both the type of leakages (to ensure both the sealine means are in serviceable condition) at LPG filing plants, before

dispatch to distributors and then to customers. If any leakage is detected during the existing checking process, the defective components are replaced or the valve is taken out of service. However there is always a minor possibility that cylinders with leaky valves as mentioned above might slip into the market considering the enormous volume of operation. It is therefore the object of the invention to provide a device, which can simultaneously detect in- situ the pin-leak and 'O'-ring-leak through the self-closing valve of the LPG cylinder,
A further object of the invention is to provide a portable leak detection device which is easy to operate and does not require any external power input. Still another object of the invention is to provide a device, which can be produced and operated economically and does not require any operational input besides an insignificant quantity of normal water.
SUMMARY OF INVENTION
Accordingly there is provided a device for leak detection in a self-closing valve of an LPG cylinder, the LPG cylinder having LPG in liquid form inside the cylinder, the self-closing valve of the cylinder having plurality of sealing means and when pressed through its spindle, emits vapourised LPG via a regulator to the stove, the device comprising atleast two individially consecutively applicable leakage detection means encapsuled in an enclosure for leakage detection through said self-closing valve, the first leak detection means comprising a tube having a top cap releasably fixed-at a top end of the tube; a nozzle attached to the tube at an opposite end; a top inner cap interposed at an upper end of the tube being pressably connected to said-top cap; a sleeve radially inwardly disposed at a lower end of the tube being press-fitted to said nozzle;; and a capillary tube extending upwardly being;

flow ably connected to said nozzle, the second leak detection means comprising an open-ended tube having a top cap and a nozzle being pressably fixable at a top end and at a bottom end thereto, a float provided inside said open-ended tube being vertically displaceable under the pressure of the LPG when leaking through said self-closing valve of the LPG cylinder.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
Fig. 1 - a schematic view of the device according to a preferred embodiment
of the invention.
Fig. 2 - a sectional view of the first leak detection means of the device as
shown in Fig- 1.
Fig. 3 - a sectional view of the second leak detection means of the device as
shown in Fig- 1.
Fig. 4 - Shows the first leak detector means of Fig - 1 in an operational
stage.
Fig. 6 - Shows the second leaked detection means of fig- 1 in an operational
phase.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE PRESENT INVENTION
Fig - 1 illustrates a device for leak detection (DLD) in a self - closing valve of an LPG-cylinder having liquefied petroleum gas in liquid form. Such a portable device can be conveniently used in-situ for checking the gas-leakage through the self-closing valve of the cylinder. The device does not require any external source of power or any operational input except a small quantity of water. The device (DLD) comprises basically two leak detection means (1,2)

encapsuled in an enclosure which are individually consecutively applied over the self-closing valve to detect any gas-leakage through the in-built sealing means of the cylinder. The first leak detection means (1) which constitutes a pin-leak tester comprises a tube (5) having a top cap (3) which can be press-fit to the tube (5); a nozzle (9) is pressably fitted at a lower end of the tube (5); a top inner cap (4) is disposed inside the tube (5) which is connected to the top cap (3); a capillary tube (7) connected to the nozzle (9) which also accommodates a sleeve (6) being pressably fitted. The second leak detection means (2) which constitutes an 'O'-ring leak tester comprises an open-ended tube (12) having a top cap (l l)i a nozzle (15) is fitted at an opposite end of the tube (12); a float (13) interposed in the tube being displaceable vertically when under the pressure of leaked LPG.
The nozzle (9) is provided with a through hole of 0 1.6 mm and the nozzle (15) is provided with a 0 0.9 mm hole from the 2,5 mm step to the central axis and hole of the same dia to meet from the center of the top 7.15 mm flat step. This top cap (3) is provided with a vent hole from top and the top cap (11) is provided with a vent hole from sides.
rO'-Rings (16) are provided on the top caps (3,11) and the nozzles (9,15). A transparent sticker of 20 cms height to be pasted to indicate water level (6) on the first leak detector means (1).
Capillary (7) to be inserted to the Nozzle (9) with a sealant (16). Further, Sleeve (6) is fitted on to the Nozzle by press fit. Top Inner cap (4) is fitted on to the Top cap (3) by press fit.
Both the assembled parts are connected in between with the acrylic tube (5) and the bottom joint is provided with a sealant (16).
The float (13) is positioned inside the tube (12) and connected to both the top cap (ll) and the nozzle (15) at both ends with a press fit. Sealant (16) are provided at both joints at the ends of the tube (12).

Figures 2 and 3 represent individually sectional views of the first leak
detection means (l) and the second detection means (2) detailing the
constructional disposition of the constituent integers.
Figure - 4 shows the working of the first leak detection means (1) which is
applied first on the self-closing valve of the LPQ-cylinder.
The first leak detection means (1) is to be placed on the cavity of Sc- valve.
In case of leak, the same passes through the hole in the nozzle (9) and
propagates through the SS capillary tube (7) inside the sleeve (6). The gas
further gets filled in the empty space of the sleeve (6). Once the volume of
leaked gas exceeds the empty space, it starts pushing the water inside the
sleeve (6). When the water level (10) inside the sleeve (6) touches the hole at
the bottom of the sleeve (6), it escapes out as bubble through the water
medium outside the sleeve (6).
The gas thus escaped, vents through the breather hole given in the Top inner
cap (4) to the atmosphere.
Fig- 5 illustrates the working of the second leak detection means (2) which is
individually consecutively applied to the self-closing valve of the LPG
Cylinder.
The Second leak detection means (2) is placed on the valve cavity and pressed
and held towards the valve from top.
The nozzle (15) presses the SC Valve spindle, thereby allowing LPG from the
cylinder to fill the Valve cavity.
Since the upper portion of the SC Valve is held sealed by the second leak
detection means (2), any leak of ORing of SC Valve, escapes through the
minute holes of the top portion of the nozzle (15) and emerges out to the
acrylic tube (12) and lifts the float (13) inside the tube (12).
The nozzles (9,15), the top caps (3, ll), the top inner cap (4) and the float (13)
comprises molded nylon. The capillary tube (7) comprise stainless steel, the

sealants and 'O' rings comprise nitrile rubber. The tubes (5,12) comprise
acrylic.
Althrough the present invention has been described with certain degree of
particularity, it is understood that the description of the preferred
embodiment is by way of example only and that numerous changes to form
and detail are possible without departing from the spirit and scope of the
invention as hereinafter claimed.



WB CLAIM
1. A device for leak detection in a self-closing valve of an LPG cylinder, the LPG cylinder having LPG in liquid form inside the cylinder, the self-closing valve of the cylinder having plurality of sealing means/and w hen pressed through its spindle, emits vapourised LPG via a regulator to the stove,/the device comprising atleast two individually consecutively applicable leakage encapsuled means disposed in an enclosure for leakage detection through said self-closing valve, the first leak detection means (1) comprising a tube (5) having a top cap (3) releasably fixed-at a top end of the tube (5); a nozzle (9) attached to the tube (5) at an opposite end; a top inner cap (4) interposed at an upper end of the tube being pressably connected to said top cap (3); a sleeve (6) radially inwardly disposed at a lower end of the tube (5) being press-fitted to said nozzle (9); and a capillary tube (7) extending upwardly being flowably connected to said nozzle (9), the second leak detection means (2) comprising an open-ended tube (12) having a top cap (11) and a nozzle (16) being pressably fixable at a top end and at a bottom end thereto, a float (13) provided inside said open-ended tube (12) being vertically displaceable under the pressure of LPG when leaking through said self-closing valve of the LPG cylinder.
2. The device as claimed in claim 1, wherein said plurality of sealing
means comprise a first sealing means and a second sealing means, and
wherein said first sealing means constitutes a sealing gasket and the
second sealing means constituting of a joint packing or '0' ring (16),
3, The device as claimed in claim 1, wherein said first leak detection
means (1) constitutes a pin leak tester detecting leakage of LPG
through the first sealing means of the self-closing valve,
■I

4. The device as claimed in claim 1, wherein said second leak detection
means (2) constitutes a 'O' ring leak tester detecting leakage of LPG
through the second sealing means of the self-closing valve.
5. The device as claimed in claim 1, wherein the top cap (3) of said pin
leak tester (1) and the top cap (11) of said '0' ring leak tester (2) is
provided with a vent hole each respectively from top and a side.
6. The device as claimed in claim 1, wherein the nozzle (4) of the pin leak
tester (l) is configured with a through hole of 0 2.00mm, and wherein
the nozzle (15) of the 'O' ring leak tester (2) is designed to have a first
hole of 0 0,8 mm to 1.00 mm originating from a step to the central axis
of the nozzle to meet with a second hole of identical diameter provided
at a center of a top flat step of the nozzle (16).
7. The device as claimed in claim 1, wherein the tube (5) has a level
indicator (6) in the form of a coloured transparent sticker indicating
the level of water-filling during its operational phase.
8. The device as claimed in any of the preceding claims, wherein the
capillary tube (7) is connected to the nozzle (9) with a 'O' ring, and
wherein both ends of said tubes (5,12) are provided with sealant in the
form of fO' rings (16).
9. The device as claimed in any of the preceding claims, wherein the top
cap (3,11), the top inner cap (4), the nozzle (9,15), the float (13)
comprise of moulded nylon, and wherein the capillary tube (7) and the
'O'-ring (16) comprises stainless steel and nitrile rubber respectively.
10,The device as claimed in any of the preceding claims, wherein said tubes (5,12) comprise acrylic.
11. A device for leakage detection in a self-closing valve of an LPG cylinder
as substantially described herein and illustrated with reference to the
accompanying figures. / l


Documents:

742-che-2004-claims duplicate.pdf

742-che-2004-claims original.pdf

742-che-2004-correspondnece-others.pdf

742-che-2004-correspondnece-po.pdf

742-che-2004-description(complete) duplicate.pdf

742-che-2004-description(complete) original.pdf

742-che-2004-drawings.pdf

742-che-2004-form 1.pdf

742-che-2004-form 19.pdf

742-che-2004-form 26.pdf

742-che-2004-form 3.pdf


Patent Number 205765
Indian Patent Application Number 742/CHE/2004
PG Journal Number 26/2007
Publication Date 29-Jun-2007
Grant Date 09-Apr-2007
Date of Filing 29-Jul-2004
Name of Patentee M/S. LPG EQUIPMENT RESEARCH CENTRE
Applicant Address P.B.NO.1618, DOORAVANINAGAR, BANGALORE 560 016.
Inventors:
# Inventor's Name Inventor's Address
1 ANBU CHERZIAN C/O. LPG EQUIPMENT RESEARCH CENTRE, P.B.NO.1618, DOORAVANINAGAR, BANGALORE 560 016.
PCT International Classification Number F17C 13/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA