INTRODUCTION Field of the Invention

The invention relates to a dry disconnect or "dry break" coupling valve.

Dry break couplings are typically used in the transfer of liquids from for example road tankers to chemical manufacturing plants, or for internal manufacturing plant transfers from various vessels and reactors to various hose lines for making and breaking of pipe systems that transfer liquids and chemicals for example.

Examples of such couplings are described in US5095946 (Victaulic Co.), CN2315365 (Wenzhou City Anti-Corrosion), CN2268155 (Hu), CN 1544835 (Xuanda), and WO2009/050173 (Single Buoy Moorings).

GB936591 (A.P.V.) describes a valve having mating discs which interlock with dowel pins. EP2535630 (Eaton) describes a lined butterfly valve. US4259980 (Miiller) also describes a butterfly valve. US4759530 (Neotecha AG) describes a stem and disc seal construction for butterfly valves.

Conventional dry break couplings use for example stainless steel and/or alloys such as

Hastelloy materials which enable high tolerances and clamping forces and therefore high sealing performance capabilities. An example is the afore-mentioned US5095946. This is perceived as being a pre-requisite in a dry break valve. However these alloys have limited application range in highly corrosive / high purity applications and can result in the leaching of extractables like Nickel, Zinc, Iron Oxide and other elements into the process media due to the effects of corrosion. This leaching process can contaminate the corrosive and/or high purity liquids being transferred. Furthermore the use of Hastelloy™ or high alloy dry break technology for widespread employment in corrosive environments is often cost-prohibitive and other more elaborate plant operations must then be employed to ensure operator and environment safety when a pipe/hose break operation must be made. Moreover, conventional dry break couplings are typically complex in design, often having internal springs and/or linkages and/or check valves and/or "dead leg" areas where pooling or liquid hold-up can occur. The internal surface finishes are difficult to polish and can be therefore not be ideal for high purity or clean applications.

Another disadvantage is that convention dry break coupling valves can be prone to thermal expansion and contraction if used with fluids at temperatures deviating much from ambient.

The invention is directed towards providing an improved coupling which:

- is more effectively dry at disconnect, and/or

- does not require expensive alloys, and/or

- is less complex, and more suitable to high purity applications, and/or

- expands the application range of dry disconnect couplings therefore increasing plant and operator safety, and/or

- is less prone to thermal expansion and contraction.

SUMMARY OF THE INVENTION

According to the invention, there is provided a coupling valve comprising:

at least two parts each having a fluid conduit and a valve member,

the valve members being configured to move together between closed and open valve positions when the parts are coupled, and

a coupling mechanism for coupling the parts together,

wherein the valve members are lined, and

wherein the valve members are arranged to press together with mutual friction in and between said open and closed valve positions.

In one embodiment, the valve members are discs, configured so that outer faces of the discs press together when the parts are coupled.

In one embodiment, at least one valve member has a sealing member arranged to press against the other valve member when the valve is closed to assist a dry seal between the valve members.

In one embodiment, the sealing member is in a recess in a valve member. - J "

In one embodiment, the coupling mechanism is arranged to press the valve members together when the parts are coupled.

In one embodiment, the coupling mechanism extends fully around the valve members.

In one embodiment, the coupling mechanism comprises a threaded collar on one part and arranged to engage a thread on the other part.

In one embodiment, the coupling mechanism comprises a hand wheel around the collar.

In one embodiment, the parts have tapered rims arranged to mutually slide to provide a centring movement as the parts are coupled by the coupling mechanism.

In one embodiment, the coupling mechanism comprises components with faces positioned to abut in the axial direction when the parts have been coupled with sufficient pressing of the valve members together.

In one embodiment, the valve members are lined with a plastics material selected from PFA, FEP, PP, PTFE, and/or PVDF.

In one embodiment, the valve members are each mounted on a shaft extending at an angle to a longitudinal axis of the coupling, one shaft being a master shaft and the other shaft being a slave shaft, rotation of the master shaft causing movement of the valve members in unison between the closed and open valve positions. In one embodiment, the angle is approximately 45°.

In one embodiment, the valve members are mounted on shafts so that rotation of the shafts moves the mated valve members from a closed position across the cross-section of the conduits to a position at or near axial within said conduits. In one embodiment, at least parts of said shafts are lined. Preferably, said lining is integral with the linings on the valve members.

In one embodiment, the valve further comprises a lock to prevent opening of the valve members when the coupling parts are uncoupled. In one embodiment, the lock comprises a bolt on one part which pushes a spigot into the circumference of a shaft on the other part, thereby allowing the shaft to rotate only when the parts are coupled. In one embodiment, the valve further comprises a lock to prevent uncoupling of the parts when the valve members are open. In one embodiment, the coupling mechanism comprises a collar, and the uncoupling lock comprises a pin which inserts and locks into said collar to prevent the collar from rotating thereby preventing accidental decoupling of the coupling parts while the valve is open.

DETAILED DESCRIPTION OF THE INVENTION

Brief Description of the Drawings

The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only with reference to the accompanying drawings in which:-

Fig. 1 is a perspective view of a dry disconnect coupling valve of the invention, in which a master part is on the right hand side and a slave part on the left; Figs. 2 and 3 are cut-away perspectives, uncoupled and coupled, in which the master part is on the left, as it is for the remaining drawings;

Fig. 4 is a full perspective view of the valve; Fig. 5 is a diagrammatic sectional view of the valve with its two main parts separated,

Fig. 6 is an end view from the left of Fig. 5;

Fig. 7 is a larger scale sectional view of the coupling mechanism when uncoupled;

Fig. 8 is a sectional view of the discs and their shafts, and Fig. 9 is a front view;

Fig. 10 is a diagrammatic sectional view with the parts coupled and the valve closed, and Fig. 1 1 shows the coupling mechanism when coupled; and Fig. 12 is a diagrammatic longitudinal sectional view of the coupling when the parts are coupled and the valve open, and Fig. 13 is an internal end view.

Description of the Embodiments

Referring to the drawings a dry break coupling valve 1 comprises a master part 2 and a slave part 3. The master part 2 has a short conduit 5 closed by a master valve disc 6 integral with a master spindle 7 at 45° to the disc 6. The slave part 3 has a slave disc 8 integral a slave spindle 9, again at a mutual angle of 45°.

Importantly, as shown most clearly in Fig. 8, the master shaft/disc assembly 7, 6 is lined with a lining 45, and the slave disc/shaft assembly 8, 9 has a lining 46 of the same material. In one embodiment, the metal of the valve is stainless steel and the lining is of PFA. The master and slave pails 2 and 3 are joined by a coupling mechanism 15. This coupling mechanism extends circumferentially around the valve 1, and it additionally includes a lock to prevent opening of the valve when the parts 2 and 3 are uncoupled. The slave part 3 has a conduit 21, and both parts 2 and 3 have outer flanges 4 and 20, typically for connection to pipework and a flexible hose (70 in Fig. 1). There may however be different means of connection, such as a threaded tube without a flange, for connection to a hose.

In various embodiments end connections can vary from tri-clamp to threaded to plain end for hose connectivity and many other varieties are possible. Fig. 6 shows a view through the conduit 5 from the left as viewed in Fig. 5, the outer flange 4 blocking view of the coupling mechanism 15.

In more detail, and as shown in most detail in Fig. 7, the coupling mechanism 15 comprises a collar 30 on the slave part 3 and having internal threads 31(a) for engaging external threads 31 (b) of the master part 2. As shown in Fig. 1, coupling and uncoupling are done with the use of a hand wheel 80 around the collar 30. This may be rotated around the valve to couple the two parts 2 and 3 together without rotating any other part of the valve and hence not causing twisting of a pipe for example. When the parts 2 and 3 are coupled the discs 6 and 8 are pressed together in a dry friction fit. This mutual friction is caused by a compression load caused by the pressure applied by the coupling mechanism 15. This mechanism applies a strong and uniform coupling force all of the way around the periphery. There is no need for springs to aid the pressing action of the discs against each other. However there is a certain inherent resilience provided by the linings 45, 46 of the discs 6 and 8. Due to the 45° angles of the spindles 7 and 9 relative to the discs 6 and 8 there is excellent transfer of pressure in the axial direction. There is also a certain degree of resilience arising from the O-ring in a recess 40 of the disc 6. As the collar is rotated there is a limit corresponding to the desired position for the discs 6 and 8 to press together. This limit is set by abutment of the collar 30 with a corresponding axially- facing face of the master part at 33. Also, the mutual movement for coupling of the parts 2 and 3 is guided by sliding contact of corresponding tapered surfaces 37 and 38 on the master and slave pails 2 and 3 respectively.

Rotation of the master shaft 7 causes both of the discs 6 and 8 and the slave shaft 9 to rotate in unison. This arrangement is simple and effective and allows the internal surfaces to be lined with a plastics material. The lining material may in various embodiments be a thermoplastic polymer or a fluoropolymer such as PFA, PP, FEP, PTFE, and PVDF. Use of a plastics lining avoids need for an expensive alloy. Also, because of the mutual compression at the disc faces the resulting friction endure that the disc face remain together and there is no need for an interlock, as in the prior art. The O-ring 60 helps to ensure that the disc faces remain dry and also assist the mutual friction and pressure. This O-ring may be easily replaced because it is exposed then the parts 2 and 3 are uncoupled.

The linings 45 and 46 of the valve discs 6 and 8 are shown most clearly in Fig. 8. The lining 45 includes a recess 40 around its faces, for the O-ring 60. In other embodiments both of the discs have such a recess and a gasket such as an O-ring. The O-ring 60 ensures that the contact faces of the linings 45 and 46 remain dry.

The valve lock comprises a tongue-shaped plug 32 of the slave part 3 for moving axially into a corresponding recess 39 of the master part 2. The lock of the mechanism 15 also comprises a lock bolt 34 which is by default pushed to the right as viewed in the drawings by a spring 35 and a spigot 36 when uncoupled (Fig. 7). Because the spigot 36 protrudes proud of the external surface of the shaft 7 and into a recess the shaft 7 is not free to rotate. However, during coupling, the plug 32 pushes the bolt 34 against the spigot 36 and the action of the opposed spring 35. When the spigot 36 is pushed to a retracted position within the circumference of the spindle 7 the spindle 7 is free to rotate under action of a handle 90 on the spindle. Hence, the discs 6 and 8 may only be opened when the parts 2 and 3 are coupled, preventing accidental opening of the valve 1 when the master and slave parts 2 and 3 are uncoupled.

Figs. 10 and 11 show the coupling valve 1 when the parts 2 and 3 are coupled and the valve is closed. The discs 6 and 8 press against each other, maintaining a dry seal between each disc face. This is augmented by the O-ring 60 in the recesses 40 and 41. Fig. 1 1 shows additional, outer, O- rings 50 and 55 for brushing against the outer edges of the discs 6 and 8 when they are in transition between the open and closed positions. Only one outer O-ring per disc will suffice in many applications.

It will be appreciated that while the valve 1 is closed there is on-axis pressure as they are at 90° to the valve axis. This provides excellent balance and symmetry, helping to maintain integrity of the seal. This effect is augmented by the fact that the parts 2 and 3 are coupled by a coupling mechanism (15) which extends fully around the valve. This balanced symmetrical approach helps to ensure that the valve discs and supports can be fully lined, even to the extent of the contacting faces which provide the friction contact being lined, as shown in Fig. 8.

Opening of the valve 1 can only occur after the parts 2 and 3 are coupled, as the spigot 36 is within the circumference of the shaft 7. This allows the handle 90 connected to the top of the shaft 7 to be rotated. This rotates not only the disc 6 but also, due to friction of their contact, the slave disc 8 and its shaft 9. Because of the relative angles (45°) of the discs and their shafts, when open, the discs are in an axial plane to provide a flow path through the coupling. This is shown in Figs 12 and 13.

The two 45° angled shaft and disc assemblies 6-9 rotate about the same axis and mate at a pre- determined compression load when the parts 2 and 3 come together. The discs 6 and 8, rotating about the same axis maintain 100% connectivity and "togetherness" - i.e. they do not "slide" across the face of each other during the rotating action, which would expose the disc faces to the liquid and result in a wet break. Because the discs are lined there is an inherent dry seal function between the disc faces when a load is maintained. The O-ring 60 is positioned between the disc faces as additional security to prevent wetting of the disc faces. The discs 6 and 8 mate and seal before fluid enters the valve, and therefore the faces of the discs remain dry when the fluid is being transferred. The linings 45 and 46 act as an excellent primary seal between the disc faces, preventing ingress of liquid during the transfer of fluid through the valve 1. When the parts 2 and 3 disengage the disc faces are consequently dry, which is important, as they are exposed.

The design is simple - avoiding complex shapes which cannot easily and cost-effectively be lined, avoiding internal springs, linkages, and other moving small parts which are difficult to line with a material such as a thermoplastic polymer / iluoropolymer material such as PFA/ FEP/ PP / PTFE / PVDF. The arrangement of the parts 30 and 33 also avoids excessive compression mating forces. High compression forces would damage the linings during the coupling process. Advantageously, the arrangement is based on 2 x ½ 180deg turn discs rotating about a common 45° axis line, the discs being positioned towards the leading edges of the valve parts 2, 3 such that when they are brought together the disc faces mate and compress to form a dry seal. A known and repeatable force is placed upon the disc faces at all times when the master and slave parts 2 and 3 are coupled.

The invention achieves the surprising function of lined valve discs being able to achieve a dry break on the basis of being pressed together, without need for a mechanical interlock. For many years, it was believed that a mechanical interlock was required, such as described in GB936591.

It will be appreciated that the invention provides a corrosion-resistant, high purity and sanitary dry-disconnect coupling using a permissible lining thereby enabling contained transfer of high purity, and/or potent, and/or highly corrosive fluids. Also, the valve 1 may be readily uncoupled even if used with liquids which subsequently tend to harden, dry or precipitate out before disassembly, such as. sugar solutions or epoxy resins. It is therefore a major improvement over currently available dry-disconnect valves which use exposed metal as dry break materials.

It will be appreciated that the invention eliminates metallic process wetted surfaces, so metallic contamination of the process media is avoided. Also, the linings are repairable for minor damage. The coupling components are non-stick due to low surface energy. The lining acts as insulator, allowing higher / lower temperature fluid operating range compared with unlined alloy units. High or low temperature liquids will not heat/cool the outer body as compared with unlined valves, therefore allowing easier handling without the necessity to employ temperature- resistant protective gloves. Also, the lining helps to prevent liquids from increasing in viscosity upon cooling, or low temperature liquids from heating.

Other advantages include the valve being antistatic, the valve requiring only low torque operation, quick assembly and disassembly, lining surfaces being automatically protected on disassembly, and small size and low weight for easy operator use.

Furthermore, the valve may be used not just as a dry break coupler but also as a throttling valve to control flow rate.

The invention is not limited to the embodiments described but may be varied in construction and detail. For example in an alternative embodiment the coupling valve comprises a lock to prevent uncoupling of the parts when the valve discs are open. When the master part and the slave part are coupled and the valve discs are in the open position, a pin inserts and locks into the collar 30. This prevents the collar 30 from rotating thereby preventing accidental decoupling of the master and slave with the valve discs in the open position. The pin becomes manually actuated by the half turn rotating action of the master shaft from closed to open. The pin remains inserted fully into the collar 30 unless the master shaft 7 is fully closed. It is also envisaged that the valve may in other embodiments have a spring acting on one or both valve member to assist the mutual pressure. Such a spring may be helical, around a shaft of a valve member for example. Although not preferable, it is envisaged that the movement of the valve members between the open and closed positions may be assisted or fully caused by a drive which moves both shafts simultaneously. This would reduce the need for a compression load between the disc faces as the master disc would not be required to drive the slave disc, however, there would still be need for mutual pressure and some friction in order to achieve a dry interface.