Title of Invention

A BODY BONNET SEAL JOINT FOR A PRESSURE SEAL VALVE

Abstract ABSTRACT A body-bonnet seal joint for a pressure seal valve comprising a pressure seal gasket made of flexible all graphite construction, the bonnet being enclosed inside the body and held in position by means of gasket pre-loading studs connected to the yoke or retaining plate, the said gasket being encased by anti extrusion rings and placed between the bonnet and a spacer ring the entire assembly resting against a segmental retainer ring, positioned inside a groove in the body, the gasket being initially compressed between the bonnet and the segmental retainer by tightening the gasket pre-loading fasteners.
Full Text

This invention relates to a body-bonnet seal joint for a pressure seal valve and constitutes an efficient body-bonnet sealing arrangement in pressure seal bonnet gate, globe & check valves, that is to say, to effectively prevent leakage of the line fluid through the body-bonnet joint mid thus provide seal tightness. Pressure seal valves are flow control valves, which employ a pressure seal bonnet mechanism to achieve seal tightness in the body-bonnet joint of the valves. The pressure seal joint uses a floating bonnet with a gasket and a segmental retainer ring to react against the upwards pressure force in the valve body, thus obviating the need for large flanges and bolts required in the known bolted bonnet valve construction. The proposed pressure seal joint is wholly contained within the valve body and utilizes the pressure inside the valve to seal the joint. In fact as the fluid pressure increases, the tightness of the seal is increased.
A pressure seal provides an effective bonnet closure for high pressure-temperature applications where pressure and thermal cycling can cause relaxation and leakage in conventional bolted bonnet design.

The material shape and the configuration of the gasket used in the pressure seal mechanism are the most important factors that influence the efficiency of seal tightness of the joint.
Different types of gaskets are used for pressure seal mechanisms. They are
broadly classified into two major types namely
metallic and non-metallic. Metallic baskets are generally made of stainless steel or soft iron with suitable plating. Non-metallic gaskets are generally graphite based.
This invention proposes an efficient body-bonnet seal joint for a pressure seal valve, the various features of which will appear from the description thereof given hereunder.
The body-bonnet seal joint for a pressure seal valve, according to this invention, comprises a pressure seal gasket made of flexible all graphite construction, the bonnet being enclosed inside the body and held in position by means of gasket pre-loading studs connected to the yoke or retaining plate, the said gasket being encased by anti extrusion rings and placed between the bonnet and a spacer ring the entire assembly resting against a segmental retainer ring, positioned inside a

groove in the body, the gasket being initially compressed between the bonnet and the segmental retainer by tightening the gasket pre-loading fasteners.
As the tluid pressure in the body cavity increases, it acts against the bonnet and pushes the bonnet assembly upwards. This further compresses the gasket and increases the effectiveness of the sealing. The anti extrusion cap rings prevent the distortion and disintegration of the graphite gasket and also provides uniform bearing against the mating components.
This will now be described with reference to the accompanying drawings, which
illustrate by way of example, and not by wav of limitation in Fig.1 an embodiment
of the subject pressure seal valve with the proposed body-bonnet
sealing depicted.
The pressure seal gasket (4) is made of flexible all graphite die moulded ring with corrosion inhibitor and metal foil reinforcement. The shape of the gasket is circular with a rectangular cross section.
The body (1) and the bonnet (2) are the pressure containing parts, which contain the flow medium and which can be used under pressure and temperature. The bonnet is enclosed inside the body and is held in position by means of gasket preloading studs S connected to the Yoke / Retaining plate (3). The Pressure seal Graphite gasket is encased by anti extrusion rings (Top & Bottom rings (5)) and

placed between the bonnet and a spacer ring (6). This entire assembly rests against the segmental retainer ring (7) which is positioned inside a groove in the body. The gasket is initially compressed between the bonnet and the segmental retainer bv means of tightening the basket pre-loading fasteners.
On compression the gasket reacts against the body & bonnet surfaces and provides sealing, there by preventing the line fluid from leaking through the joint. As the
fluid pressure in the body cavity increases, it acts against the bonnet and pushes the bonnet assembly upwards. This further compresses the gasket and increases the effectiveness of the sealing. Hence in this pressure seal mechanism the fluid pressure aids in sealing and higher the fluid pressure better will be the sealing. The anti extrusion cap rings prevent the distortion and disintegration of the graphite gasket and also provides uniform bearing against the mating components.

We Claim:
1. A body-bonnet seat joint for a pressure seal valve comprising a pressure seal
gasket made of flexible all graphite construction, the bonnet being enclosed inside
the body and held in position by means of gasket pre-loading studs connected to
the yoke or retaining plate, the said gasket being encased by anti extrusion rings
and placed between the bonnet and a spacer ring the entire assembly resting
against a segmental retainer ring, positioned inside a groove in the body, the
gasket being initially compressed between the bonnet and the segmental retainer
by tightening the gasket pre-loading fasteners.
2, A body-bonnet seal joint for a pressure seal valve wherein the gasket has a
construction of die moulded ring with corrosion inhibitor and metal foil
reinforcement.
3. A body-bonnet seal joint for a pressure seal valve wherein the gasket is circular
with a rectangular cross section.
4, A body-bonnet seal joint for a pressure seal valve substantially as herein
described with reference to, and as illustrated in, the accompanying drawings.


Documents:

0184-che-2007 correspondence po.pdf

0184-che-2007 drawings.pdf

184-CHE-2007 AMANDED CLAIMS 21-10-2009.pdf

184-CHE-2007 AMANDED PAGES OF SPECIFICATION 21-10-2009.pdf

184-CHE-2007 EXAMINATION REPORT REPLY RECIEVED 21-10-2009.pdf

184-che-2007-abstract.pdf

184-che-2007-claims.pdf

184-che-2007-correspondnece-others.pdf

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

184-che-2007-form 1.pdf

184-che-2007-form 18.pdf

184-che-2007-form 26.pdf


Patent Number 241012
Indian Patent Application Number 184/CHE/2007
PG Journal Number 25/2010
Publication Date 18-Jun-2010
Grant Date 15-Jun-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 KALYAN SHIVANAGOUDA PATIL AUDCO INDIA LIMITED, MOUNT POONAMALEE ROAD, MANAPAKKAM, CHENNAI 600089
3 SELLAMUTHU MADURAIVEERAN AUDCO INDIA LIMITED, MOUNT POONAMALEE ROAD, MANAPAKKAM, CHENNAI 600089
PCT International Classification Number F16K27/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA