GB2520573A

GB2520573A - A ring seal and flange clamping system

Info

Publication number: GB2520573A
Application number: GB1320860.8A
Authority: GB
Inventors: Michael John Fenner
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-11-26
Filing date: 2013-11-26
Publication date: 2015-05-27
Also published as: GB201320860D0

Abstract

A unitary ring seal made of a resilient material 100 and a ferrule/flange 200, adapted to accept the ring seal 100 are provided. The ring seal 100 comprises three portions: an upper generally ring-shaped portion 102 that is of approximately conical cross section, configured to engage a conventional flange/ferrule circular groove; a middle washer-shaped portion 106; and a lower generally ring shaped portion 108 that has two sidewalls 112, 114 that converge as they approach and eventually join with the middle portion 106, configured to engage a correspondingly shaped circular groove 204 in the ferrule/flange 200.

Description

A Ring Seal and Flange Clifinping System

FIELD OF INVENTION

The present invention relates to equipment for coupling and uncoupling processing equipment such as pipework, and vessels having coupling flanges; especially as used in the pharmaceutical industry.

BACKGROUND OF fNVENTION

In batch manufacturing processes, for example; as used in the pharmaceutical industry; there is frequently a need to assemble and disassemble process equipment items. For example; this may be necessary as part of a batch manufacturing process or to allow sampling during the manufacture of a pharmaceutical product. In addition, there are other industrial processes that have such requirements. Removable coupling systems are known and widely available that allow relatively rapid assembly or disassembly of pipework.

For example Tn-Clover TM fittings as manufactured by Alfa Laval TM (USA). These clamping systems comprise two flanges -one welded to the end of each pipe and a gasket which goes between them. The assembly (flanges and intennediate gasket) is typically held together under tension using a hand-tightened clamp; this allows rapid disassembly. Alternatively flanges of similar systems may be clamped using bolts, tightened by spaimers.

A common problem with such systems is that the gasket is difficult to hold in place whilst the items are being assembled; particularly when the axis of the flange is near vertical. This has been partly addressed by some suppliers by the provision of a down-turn at the edge of the gasket, which is intended to grip the edge of the flange. However, this does not always hold the gasket in place duing assembly, necessitating repeated attempts to join and seal pipework. Typically, the gasket is initially misaligned, and so does not seal properly Alternatively, the gasket can become totally dislodged and fall into a processing vessel causing subsequent loss or damage; or fall into inaccessible locations, particularly when materials are being handled within isolators or glove-boxes. These problems are commonly encountered during hatch manufacturing processes used in the pharmaceutical industry, and also certain general chemical manufacturing processes; where materials being contained in the processing equipment are extremely toxic or otherwise hazardous; for example, products of biological fermentation processes.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved gasket that is held more securely in place during assembly between flanges; and an improved flange/ferrule or end plate that will accept such a gasket. Another aim is to provide a system that allows more rapid assembly of a gasket within a flange, ferrule, disc (blaiildng/end plate) etc., by more securely holding a gasket in place while it is being clamped between flanges etc..

In one aspect the invention comprises a ring seal (gasket) having an integral (one component) sealing ring of resilient material and where in cross section said ring comprises three portions: an upper generally triangular/conical portion; an intermediate sealing portion; and a lower portion comprising inner and outer sidewall parts that slope toward each other (get closer) as they approach (in the direction of) the inteimediate flange sealing portion. Said sidewalls are preferably generally planar when viewed in (radial) cross-section.

In another aspect the invention comprises: a unitary nng seal (gasket) made of a resilient material comprising three portions: an upper generally ring-shaped portion that is of approximately triangular/conical cross section; but with a rounded head, this portion being configured to engage a conventional flange/ferrule circular groove; a middle washer-shaped portion (gasket) and a lower generally ring shaped portion; characterized in that said lower portion has two sidewalls that converge as they approach and eventually join with the middle portion. Said sidewalls are preferably generally planar when viewed in (radial) cross-section.

In either of the above aspects, preferably, at least one of the base angles of the lower portion (fi -defined as the angle fonned between the lower planar surface of the intermediate sealing portion and the sloping sidewall part of the lower portion) of the ring seal are in the range 70-80°; and preferably in the range 72-78°. The lower portion may have a flat base; a concave base; or a convex base.

In either of the above aspects, preferably, the lower portion of the ring seal is generally isosceles trapezoid in shape.

The intermediate sealing portion of the ring seal may be generally rectangular in shape.

In either of die above aspects, preferably, the lower portion of the nng seal has at least one rounded base corner portion.

In another aspect the invention comprises a flange/ferrule or disc-shaped closure plate having a annular groove shaped/adapted to accept, in a generally seal-tight manner, the (resilient) lower portion of a ring seal according to the present invention.

In another aspect the flange/ferrule or disc-shaped closure plate comprises: a generally annular-shaped groove defined by an inner sidewall an outer sidewall and an annular floor portion; where the top of the inner wall and outer side wall each adjoin planar portions of the top face of said flange/felTule or plate to form two circular edges; where the space between these edges defmes an annular entry portion (F); and wherein the annular floor portion is wider than the annular entry portion (E).

In either of the above aspects the flange/ferrule or disc-shaped closure plate preferably has at least one side wall inclined at an angle (a) of to the axis of die flange or ferrule; where a is in the range 10-20°; and preferably in the range 12-18°.

In a further aspect the invention comprises a flange/ferrule clamping system having a ring seal according to the invention (as described above) and a flange/ferrule or disc-shaped closure plate according to the invention (as described above)

BRIEF DESCRIPTION OF DRAWINGS

Preferred embodiments of the invention are illustrated by the following diagrammatic drawings in which: Figure la shows a cross-sectional view of part of the ring seal (gasket)of the present invention; Figure lb shows a corresponding part of a ferrule according to the present invention that accepts the ring seal of Figure la; Figure 2a shows a diametric cross section view of the ring seal (gasket) partly shown in Figure Ia; Figure 2b shows a diametric cross section of a ferrule according to the present invention that accepts the ring seal of Figure 2a; Figure 3 shows a perspective (partly cut-away) view of the nng seal shown in Figure 2a; and Figure 4 shows a perspective (partly cut away) view of an end plate (disc) adapted to accept the ring seal of Figure 2a.

DESCRIPTION OF TI-IF INVENTION

Preferred embodiment of the invention will now be described by reference to Figures 1 to 4.

Figure 2a shows a diametric cross section view of a ring seal (gasket) according to a fir st embodiment of the present invention. A flange ring seal (100) comprises an integral/unitary sealing ring of resilient material which in cross section (see enlarged partial view of Figure la) has three portions; an upper generally conical portion (102) with a rounded head (104); an intermediate flange sealing portion (106); and a lower generally trapezoid-shaped portion (108) with a flat lower base (110) and a pair of inwardly sloping sidewalls (112, 114). The base angles (ii) of the lower trapezoid portion (108) is preferably approximately 75°; and typically in the range 70-80°. The angle between the upper sidewalls (116, 118) leading to the rounded head (104) is approximately 45°. The junctions of the upper portion (102) and the lower portion (108) with the intermediate flange sealing portion (106) are preferably slightly rounded; as it the junction of the sloping sidewalls (112, 114) with the base (110) of the trapezoid (all as viewed in cross-section -as shown in Figures la and 2a). The ring seal (100) is typically made of a resilient material such as silicone rubber Figure 3 shows the ring seal (gasket) of Figure 2 in a (partly cut-away) perspective view.

The unitary ring seal (100) made of a resilient matenal comnpnses three portions: an upper generally ring-shaped portion (102) that is of approximately conical cross section; but with a rounded head (104), this portion being configured to engage a conventional flange/ferrule circular groove; a middle washer-shaped portion (106); and a lower generally ring shaped portion (108); this lower portion having inner and outer sidewall parts that converge as they approach and eventually join with the middle portion (106) Figure 2b shows diametric cross section view of a flange/ferrule (200) configured to tightly engage the lower trapezoid portion (108) of a ring seal (gasket) according to the present invention. This differs from known flanges in that it has a generally annular-shaped groove (204) defined (when viewed in radial cross section) by an inner sidewall (206) an outer sidewall (208) and an annular floor portion (210); where the top of the inner wall and outer side wall each adjoin planar portions of the top face of said flange/ferrule (200) to form two curved edges (212, 214); where the space between these edges defines an annular entry portion (E); and wherein the annular floor portion (210) is wider than the annular entry portion (F). Typically, the inner sidewall (206) and the outer sidewall (208) are inclined at an angle a to the axis (A-A') of the flange; where a is typically 15° ; nonnally in the range 5-25° ; and preferably in the range 10-20°. The annular-shaped groove (204) is configured to snugly house the (removable) lower ring shaped portion (108) of the above-described ring seal (gasket) 100.

Figure 4 shows a diametric cross section of an end plate/disc (202) adapted to accept the ring seal of Figures 2a and 3. This differs from known end plates in that it has a generally annular-shaped groove (204) defined (when viewed in diametric cross section) by an im-ier sidewall (206) an outer sidewall (208) and an annular floor portion (210); where the top of the inner wall and outer side wall each adjoin planar portions of the top face of said plate (202) to form two curved edges; where the space between these edges defines an annular entry portion (E); and wherein the annular floor portion (210) is wider than the annular entry portion (F). Typically, the inner sidewall (206) and the outer sidewall (208) are inclined at an angle a to the axis of the flange; where a is typically 15° and normally in the range 5-25° ; and preferably in the range 10-20°. The annular-shaped groove (204) is configured to snugly house a reinovable) lower nng shaped portion (108) of the above-described ring seal (gasket) 100.

Claims

CLAIMS1. A ring seal (100) comprising an integral (one component) sealing ring of resilient material and where in cross section said ring comprises three portions: an upper generally conical portion (102); an intermediate sealing portion (106); and a lower portion (108) comprising inner and outer sidewall parts (112, 114) that slope toward each other (get closer) as they approach (in the direction of) the intermediate flange sealing portion (106).
2. A ring seal (100) according to Claim 1 where at least one of the base angles (I defined as the angle formed between the lower planar surface of the intermediate sealing portion and the sloping sidewall part of the lower portion) of the lower portion (108) are in the range 70-80°; and preferably in the range 72-78°.
3. A ring seal according to any preceding claim where the lower portion (108) has a flat base (110); a concave base; or a convex base.
4. A ring seal (100) according to any preceding claim wherein in cross-section the lower portion (108) is generally isosceles trapezoid in shape.
5. A ring seal (100) according to any preceding claim wherein in cross section the intermediate sealing portion (106) is generally rectangular in shape.
6. A ring seal (100) according to any preceding claim where the lower ring portion (108) has at least one rounded base corner portion (120).
7. A flange/ferrule (200) or disc-shaped closure plate (202) having a annular groove (204) shaped/adapted to accept, in a generally seal-tight maimer, the (resilient) lower portion (108) of a ring seal (100) according to any preceding claim or Claim 11.
8. A flange/ferrule (200) or disc-shaped closure plate (202) according to Claim 7 and further comprising: a generally annular-shaped groove (204) defined by an inner sidewall (206) an outer sidewall (208) and an amiular floor portion (210); where the top of the inner wall and outer side wall each adjoin planar portions of the top face of said flange/ferrule (200) or plate (202) to form two curved edges (212, 214); where the space between these edges defines an annular entry portion (F); and wherein the annular floor portion (210) is wider than the annular entry portion (F).
9. A flange/ferrule (200) or disc-shaped closure plate according to Claim 7 or 8 having at least one side wall inclined at an angle (a) to the axis of the flange or ferrule; where a is in the range 10-20°; and preferably in the range 12-18°.
10. A flange/ferrule clamping system (10) comprising a nng seal (100) according to any of Claims 1 to 6 and a flange/ferrule (200) or disc-shaped closure plate (202) according to Claim 7 to 9 or 11.
11. A unitary nng seal (100) made of a resilient material comprising three portions: an upper generally ring-shaped portion (102) that is of approximately conical cross section; this portion being configured to engage a conventional flange/ferrule circular groove; a middle washier-shaped portion (106); and a lower generally ring shaped portion (108); characterized in that said lower portion has two sidewalls (112, 114) that converge as they approach and eventually join with the middle portion (106)
12. A ring seal (100) according to Claim I or II where the sidewall parts (112, 114) are at least partially planar when viewed in (radial) cross-section.