Title of Invention	A DOUBLE ISOLATION PLUG VALVE
Abstract	A double isolation plug valve, comprising two plugs, both of w0hic1 are provided with a wrench or hand, wheel that can be operated at the same level; a stem to operate the plug being housed in a covet a set of disc springs for plug loading, housed inside a counter bore (?) in the cover and arranged in parallel or in series, the said disc springs being positioned at the large end of the plug-, a thrust ball bearing provided between the disc springs and the top face of the plug to prevent rotation Of the disc springs while the plug is in operation; means for operating the said valve manually or electro-mechanically .

Title of Invention

A DOUBLE ISOLATION PLUG VALVE

Abstract

A double isolation plug valve, comprising two plugs, both of w0hic1 are provided with a wrench or hand, wheel that can be operated at the same level; a stem to operate the plug being housed in a covet a set of disc springs for plug loading, housed inside a counter bore (?) in the cover and arranged in parallel or in series, the said disc springs being positioned at the large end of the plug-, a thrust ball bearing provided between the disc springs and the top face of the plug to prevent rotation Of the disc springs while the plug is in operation; means for operating the said valve manually or electro-mechanically .

Full Text	AUDCO INDIA LIMITED, MOUNT PONAMALLEE ROAD, MANAPAKKAM, w CHENNAI 600089, TAMIL NADU, INDIA, AN INDIAN COMPANY. THIS FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED. This invention relates to a double isolation plug valve. The known double isolation plug valve has a flow passage having an inlet and outlet for the inflow and outflow of fluid. The body has two taper bores which accommodate two plugs. The plugs have flow passage similar to the body and are housed inside the taper bores provided on the body. The plugs, when rotated control the flow of the fluid through the valve. The flow is enabled, when the plugs are positioned in such a way that flow passages are aligned with the body port. When the plugs are in closed position, the flow is isolated. A cavity is formed when the two plugs are in closed position. There is a bleed port connecting this center cavity to atmosphere. The operation of the plug is made possible by a stem which is connected to the plug by means of an equalizer ring. The stem packing is injected through a stem packing injector which prevents the leakage of the contained fluid to the atmosphere. A gear box interfaces with the flange provided on the body and receives the stem to operate the valve plug. The plug is positioned inside the taper bore through a pressure screw. The requirement of adjustment of the pressure screw to keep the plug positioned inside the taper bore is a disadvantage. When the valve is operated over a prolonged period, the pressure screw has a tendency to loosen. In such case the pressure screw would need re-adjustment to the correct torque, which otherwise would hamper the performance of the valve. The known valve has a spring disc and bearing pad at the large end of the plug. The plug is seated inside the taper bore through a pressure screw. The pressure screw is adjusted to a predetermined torque to axially load the plug. The double isolation plug valve, according to this invention, comprises two plugs, both of which are provided with a wrench or hand wheel that can be operated at the same level; a stem to operate the plug being housed inside a cover; a set of disc springs for plug loading, housed inside a counter bore inside the cover and arranged in parallel or in series, the said disc springs being positioned at the large end of the plug; a thrust ball bearing provided between the disc springs and top face of the plug to prevent rotation of the disc springs while the plug is in operation; means for operating the said valve manually or elector-mechanically. This invention will now be described with reference to the accompanying drawings which illustrate by way of example, and not by way of limitation, one of possible embodiments of the double isolation valve proposed herein, wherein Figs. 1 and 2 illustrate two views of the said embodiments. The embodiment has a valve body (1) with two taper bores which are reverse oriented to each other at 180 degrees and having a passage way (2). The plugs (3) & (4) have similar flow passages (5) & (6) and are inserted inside the respective taper bore which controls the flow of fluid through the valve. When the flow passages of plugs are oriented inline with the passage (2) in the body of the valve is said to be in open position. When the plug flow passages (5) & (6) are oriented perpendicular to the flow passage (2) in the body, the valve is said to be in closed position. The operation of plugs is made through stems (7) & (8), which are connected to the plug through an equalizer ring (10). The valve sealant is injected into the system through the sealant injector (11). The valve body and plugs have inbuilt grooves and ducts for receiving and spreading the sealant. The sealant film formed between the plug and body tapers help in providing positive isolation and also helps in reducing the operating torque of the valve. The stem sealing is made A ugh stem packing injected through the stem packing injector (11). The stem packing flows and gets pressurized inside the groove (12) provided on the stems (7) & (8). Thus injected, the stem packing prevents the leak of the fluid handled by the valve to the atmosphere. What is stated above are the known features of the double isolation plug valve. The novel features of the double isolation plug valve proposed herein are: Both plugs (3) & (4) are provided with a wrench or gear unit (13) with hand wheel (14) that can be operated at the same level. The stem (7) to operate the plug (3) is housed in a cover (15). The plug loading is by means of a set of disc springs (16) arranged parallel or in series. For the plug (3), which is oriented with the large end of the plug at the top, the disc springs are positioned at the large end of the plug. To prevent rotation of the disc spring while the plug is in operation, a thrust ball bearing (17) is provided between the disc springs and the top face of the plug. Plug (4), which is oriented with the small end of the plug at the top, the disc springs are positioned at the large end and housed inside a counter bore (18) in the cover. In the proposed valve it is possible to operate the plug from the same height or level. The proposed valve eliminates the pressure screw thus eliminating the requirement for frequent re-adjustments. The proposed valve could be operated manually by means of a lever or mounted gear unit. The gear unit can be actuated by electrical actuators. The proposed valve can accommodate a bigger plug and hence more port opening area can be achieved. In the view of the larger port opening area, the pressure drop across the proposed valve will be less. It will be appreciated that various other embodiments of the double isolation plug valve are possible without departing from the scope ambit of this invention. We Claim: 1. A double isolation plug valve, comprising two plugs, both of which are provided with a wrench or hand wheel that can be operated at the same level; a stem to operate the plug being housed in a cover; a set of disc springs for plug loading, housed inside a counter bore in the cover and arranged in parallel or in series, the said disc springs being positioned at the large end of the plug; a thrust ball bearing provided between the disc springs and the top face of the plug to prevent rotation of the disc springs while the plug is in operation; means for operating the said valve manually or electormechanically. 2. A double isolation plug valve as claimed in Claim 1 wherein the primary stem seal comprises of die-molded packings rings compressed and housed inside a stuffing box. 3. A double isolation plug valve as claimed in Claim 1 wherein the said means comprise a lever. 4. A double isolation plug valve as claimed in Claim 1 wherein the said means comprise a mounted gear unit which is actuated electrically. 5. A double isolation plug valve substantially as herein described and illustrated with reference to the accompanying drawings.

Full Text

AUDCO INDIA LIMITED, MOUNT PONAMALLEE ROAD, MANAPAKKAM, w
CHENNAI 600089, TAMIL NADU, INDIA, AN INDIAN COMPANY.
THIS FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED.
This invention relates to a double isolation plug valve.
The known double isolation plug valve has a flow passage having an inlet and outlet for the inflow and outflow of fluid. The body has two taper bores which accommodate two plugs. The plugs have flow passage similar to the body and are housed inside the taper bores provided on the body. The plugs, when rotated control the flow of the fluid through the valve. The flow is enabled, when the plugs are positioned in such a way that flow passages are aligned with the body port. When the plugs are in closed position, the flow is isolated. A cavity is formed when the two plugs are in closed position. There is a bleed port connecting this center cavity to atmosphere.
The operation of the plug is made possible by a stem which is connected to the plug by means of an equalizer ring. The stem packing is injected through a stem packing injector which prevents the leakage of the contained fluid to the atmosphere. A gear box interfaces with the flange provided on the body and receives the stem to operate the valve plug. The plug is positioned inside the taper bore through a pressure screw.
The requirement of adjustment of the pressure screw to keep the plug positioned inside the taper bore is a disadvantage. When the valve is operated over a prolonged period, the pressure screw has a tendency to loosen. In such case the pressure screw would need re-adjustment to the correct torque, which otherwise would hamper the performance of the valve.
The known valve has a spring disc and bearing pad at the large end of the plug. The plug is seated inside the taper bore through a pressure screw. The pressure screw is adjusted to a predetermined torque to axially load the plug.
The double isolation plug valve, according to this invention, comprises two plugs, both of which are provided with a wrench or hand wheel that can be operated at the same level; a stem to operate the plug being housed inside a cover; a set of disc springs for plug loading, housed inside a counter bore inside the cover and arranged in parallel or in series, the said disc springs being positioned at the large end of the plug; a thrust ball bearing provided between the disc springs and top face of the plug to prevent rotation of the disc springs while the plug is in operation; means for operating the said valve manually or elector-mechanically.
This invention will now be described with reference to the accompanying drawings which illustrate by way of example, and not by way of limitation, one of possible embodiments of the double isolation valve proposed herein, wherein
Figs. 1 and 2 illustrate two views of the said embodiments.
The embodiment has a valve body (1) with two taper bores which are reverse oriented to each other at 180 degrees and having a passage way (2). The plugs (3) & (4) have similar flow passages (5) & (6) and are inserted inside the respective taper bore which controls the flow of fluid through the valve. When the flow passages of plugs are oriented inline with the passage (2) in the body of the valve is said to be in open position. When the plug flow passages (5) & (6) are oriented perpendicular to the flow passage (2) in the body, the valve is said to be in closed position.
The operation of plugs is made through stems (7) & (8), which are connected to the plug through an equalizer ring (10). The valve sealant is injected into the system through the sealant injector (11). The valve body and plugs have inbuilt grooves and ducts for receiving and spreading the sealant. The sealant film formed between the plug and body tapers help in providing positive isolation and also helps in reducing the operating torque of the valve.
The stem sealing is made A ugh stem packing injected through the stem packing injector (11). The stem packing flows and gets pressurized inside the groove (12) provided on the stems (7) & (8). Thus injected, the stem packing prevents the leak of the fluid handled by the valve to the atmosphere.
What is stated above are the known features of the double isolation plug valve.
The novel features of the double isolation plug valve proposed herein are:
Both plugs (3) & (4) are provided with a wrench or gear unit (13) with hand wheel (14) that can be operated at the same level.
The stem (7) to operate the plug (3) is housed in a cover (15).
The plug loading is by means of a set of disc springs (16) arranged parallel or in series.
For the plug (3), which is oriented with the large end of the plug at the top, the disc springs are positioned at the large end of the plug. To prevent rotation of the disc spring while the plug is in operation, a thrust ball bearing (17) is provided between the disc springs and the top face of the plug.
Plug (4), which is oriented with the small end of the plug at the top, the disc springs are positioned at the large end and housed inside a counter bore (18) in the cover.
In the proposed valve it is possible to operate the plug from the same height or level. The proposed valve eliminates the pressure screw thus eliminating the requirement for frequent re-adjustments.
The proposed valve could be operated manually by means of a lever or mounted gear unit.
The gear unit can be actuated by electrical actuators.
The proposed valve can accommodate a bigger plug and hence more port opening area can be achieved.
In the view of the larger port opening area, the pressure drop across the proposed valve will be less.
It will be appreciated that various other embodiments of the double isolation plug valve are possible without departing from the scope ambit of this invention.
We Claim:
1. A double isolation plug valve, comprising two plugs, both of which are provided with a wrench or hand wheel that can be operated at the same level; a stem to operate the plug being housed in a cover; a set of disc springs for plug loading, housed inside a counter bore in the cover and arranged in parallel or in series, the said disc springs being positioned at the large end of the plug; a thrust ball bearing provided between the disc springs and the top face of the plug to prevent rotation of the disc springs while the plug is in operation; means for operating the said valve manually or electormechanically.
2. A double isolation plug valve as claimed in Claim 1 wherein the primary stem seal comprises of die-molded packings rings compressed and housed inside a stuffing box.
3. A double isolation plug valve as claimed in Claim 1 wherein the said means comprise a lever.
4. A double isolation plug valve as claimed in Claim 1 wherein the said means comprise a mounted gear unit which is actuated electrically.
5. A double isolation plug valve substantially as herein described and illustrated with reference to the accompanying drawings.

Documents:

0180-che-2007 correspondence po.pdf

180-che-2007 amanded claims 23-02-2010.pdf

180-CHE-2007 CORRESPONDENCE OTHERS 23-02-2010.pdf

180-CHE-2007 AMANDED CLAIMS 07-10-2009.pdf

180-CHE-2007 EXAMINATION REPORT REPLY RECIEVED 07-10-2009.pdf

180-che-2007-abstract.pdf

180-che-2007-claims.pdf

180-che-2007-correspondnece-others.pdf

180-che-2007-description(complete).pdf

180-che-2007-drawings.pdf

180-che-2007-form 1.pdf

180-che-2007-form 18.pdf

180-che-2007-form 26.pdf

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Patent Number

241453

Indian Patent Application Number

180/CHE/2007

PG Journal Number

28/2010

Publication Date

09-Jul-2010

Grant Date

05-Jul-2010

Date of Filing

29-Jan-2007

Name of Patentee

AUDCO INDIA LIMITED

Applicant Address

AUDCO INDIA LIMITED, MOUNT POONAMALEE ROAD, MANAPAKKAM, CHENNAI-600089.

Inventors:

#	Inventor's Name	Inventor's Address
1	RAMAKRISHNAN MURUGANANTHAM	AUDCO INDIA LIMITED, MOUNT POONAMALEE ROAD, MANAPAKKAM, CHENNAI-600089.
2	NARAYANAN VASUDEVAN	AUDCO INDIA LIMITED, MOUNT POONAMALEE ROAD, MANAPAKKAM, CHENNAI 600089

PCT International Classification Number

E21B43/16

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA