VALVE

FIELD OF INVENTION

[0001] The present invention relates to a valve, in particular, to a valve suitable for high pressure applications.

BACKGROUND OF THE INVENTION

[0002] Valves are commonly used to control the flow rate, pressure and/or flow direction of fluids. As used herein, the word "fluid" may mean liquid, gas, solution, emulsion, suspension, and/or combinations or

mixtures thereof, and a fluid may comprise undissolved particles or other solids and may alternatively or additionally include homogeneous or heterogeneous mixtures comprising at least one liquid substance. A valve generally comprises a valve body, a disc, an actuator, sealing and fixing elements, and its fluid control function is obtained by actuating the disc to rotate or slide or otherwise move to change the flow direction or the flow area size of a fluid. As a widely used mechanism in industry and civil appliances, many kinds of valves for different applications can be found in the market. For example, a switching valve is able to switch between two or more work states so as to change the flow direction or flow path of a fluid, while a selector valve is for selecting one of two or more fluid streams and letting the rest be plugged up or gathered for discharging

together through a separate path.

[0003] Generally, in these valves, a force for ensuring a valid engagement of the valve body and the disc is provided by a spring or the like. However, after several times of uses, elastic fatigue may occur in the spring. Especially if the valve is used for high pressure fluid under high temperature conditions, it is even possible that the spring would fatigue and lose its elasticity after one time of use and therefore cannot provide a force strong enough to ensure reliable sealing effect and prevent leaking and gas-channeling problems.

[0004] Therefore, it is desired to provide a valve suitable for high pressure applications, which has reliable sealing effects and is capable of being repeatedly used without sealing failure.

SUMMARY OF THE INVENTION

[0005] Embodiments of the present invention provides a valve which comprises a valve body provided with a first engagement face defining a plurality of ports, and a rotatable core provide a second engagement face engaging with the first engagement face and a pressure balance face adapt to receive a pressure from a balance fluid in order to balance the pressure received from the first engagement face.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Fig. 1 is an assembled cross-section view of a selector valve according to one embodiment of the invention.

[0007] Fig. 2 is an exploded perspective view of the selector valve of

Fig. 1, showing an upper cover, a detached two-piece core and a lower cover.

[0008] Fig. 3 is a view showing another embodiment of core in which a connecting structure is different from that of Fig. 2.

[0009] Fig. 4 is a view showing another kind of selector valve according to one embodiment of the invention.

[0010] Fig. 5 is a view showing a switch valve according to one embodiment of the invention.

[0011] Fig. 6 is a view showing a first engagement state of the valve of

Fig. 5.

[0012] Fig. 7 is a view showing a second engagement state of the valve of Fig. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Figs. 1-3 illustrate a selector valve for controlling high pressure gases, which is capable of selecting one gas stream from a plurality of gas inlets and outputting it through a selected stream outlet, and gathering the other unselected streams and outputting them through another outlet.

[0014] As shown in Fig. 1, the selector valve 100 includes a valve

body 1, and a core 3 accommodated in the valve body 1. In one embodiment, the valve body 1 includes an upper cover 11 and a lower cover 12 which can be fixed together with bolts and sealed with an O-ring 42.

[0015] The lower cover 12 has an upper surface 120 which serves as a first engagement face. In one embodiment, the upper surface 120 is flat. There are a plurality of ports on the first engagement face 120. In one embodiment, the ports 121 serve as gas inlets and the port 122 serves as a gas outlet. The gas inlets 121 are connected to gas supplying conduits outside the valve through gas inputting channels 21, and the selected stream outlet 122 is connected to a gas venting conduit outside the valve through an outputting channel 22, wherein the connections or joints

between the inputting channels or outputting channel and respective gas supplying conduits or gas venting conduit are sealed with ferrules.

[0016] The upper cover 11 defined a room 111 for accommodating the core 3. In one embodiment, the core 3 in the room 111 partially projects out from the top opening of the upper cover 11 for connecting to a driver

device or the like which drives the core 3 to rotate. There is an O-ring 41 between the core 3 and the upper cover 11 for sealing.

[0017] In one embodiment, the core is a two-piece structure including an upper part (upper core part) 31 and a lower part (lower core part) 32. The upper part 31 serves as an actuating member for actuating the lower

part 32 to rotate, and is connected to the driver device outside the valve. The lower part 32 serves as an engaging member providing a bottom

surface 320 as a second engagement face for engaging with the first engagement face 120 of the lower cover 12. The second engagement face 320 defines grooves corresponding to the gas inlets 121 and the selected stream outlet 122 on the first engagement face 120 (details about the grooves will be described in conjunction with Fig. 2 hereafter). In one

embodiment, the lower part 32 further provides an upper surface 30 as a pressure balance face for receiving a pressure force of a balance fluid in order to balance a pressure force exerted on the second engagement face 320 by the gases inputted by the gas inlets 121 of the first engagement face 120, wherein any fluid which directly or indirectly exerts a pressure force to the pressure balance face so as to balance the pressure on the second engagement face 320 may be a balance fluid.

[0018] In one embodiment, a cavity 313 is formed between the upper and lower parts 31 and 32 and an elastic member 33 is disposed in the cavity 313. The elastic member 33 provides an elastic force to the lower part 32 to preliminarily keep the second engagement face 320 abutting the first engagement face 120 and therefore to prevent the lower part 32 from undesired movement when the cavity 313 is not filled with a balance fluid, and also to auxiliarily press the lower core part 32 when the cavity 313 is filled with a balance fluid. In one embodiment, the elastic member 33

includes a plurality of disc springs, and there is further a washer 34 for retaining the disc springs 33 and also for uniformly transferring the

elastic force of the disc springs to the lower part 32 of the core 3. A balance fluid may fill the rest space of the cavity 313 which is not occupied by the disc springs 33 and the washer 34 and directly or indirectly exerts a pressure force to the pressure balance face 30. For instance, if the washer 34 is a solid one and has a surface closely abut the pressure balance face 30 just as illustrated in Fig. 1, a pressure force of the balance fluid may be exerted on the washer 34 and then is transferred to the pressure balance face 30, but if a plurality of through holes are defined in the washer 34 and make the balance fluid able to contact the pressure balance face 30, a pressure force of the balance fluid may be either directly exerted on the pressure balance face 30 or exerted on the washer 34 and transferred to the pressure balance face 30.

[0019] Due to the presence of the pressure force of the balance fluid, it is no longer to rely on the elastic force of the spring 33 to balance the pressure on the second engagement face 320. Therefore, the valve has reliable sealing effects and is capable of being repeatedly used without sealing failure at a high pressure condition or even under a condition of

high pressure and high temperature.

[0020] Once the bottom surface 320 of the lower core part 32 (the second engagement face) wears out and the thickness of the lower core

part 32 decreases after many times of uses, the thickness loss can be made up by simply adding one or more adjustment sheets between the lower core part 32 and the washer 34, such that a reliable engagement of the first and second engagement faces 120 and 320 can be maintained.

[0021] The upper core part 31 abuts a shoulder portion 112 formed on the upper cover 11 via a planar bearing 35 sandwiched by a pair of

washers (the planar bearing 35 can prevent the upper core part 32 and the shoulder portion 112 from gnawing at each other during rotation), and

thereby is upwardly immoveable.

[0022] As shown in Fig. 2, there are bolt holes correspondingly defined in the upper and lower covers 11 and 12 which are respectively denoted as 113 and 123. In one embodiment, there are seventeen ports in the first engagement face 120, including sixteen gas inlets 121 each for inputting a stream of gas and one selected stream outlet 122 for

outputting a selected stream of gas. There is no restriction as to the number of the gas inlets or the selected stream outlets, which can be changed according to actual implementation. For example, there can be two gas inlets and one selected stream outlet, three gas inlets and one selected stream outlet, or two gas inlets and two selected stream outlets.

[0023] The upper core part 31 comprises a shaft 311 to project out of the valve for connecting to a driver or the like, and a swivel 312 for housing the lower core part 32. The swivel 312 is formed with a pair of

notches 317 in the lateral wall thereof and correspondingly the lower core part 32 is provided with a pair of location pins 327 which are respectively received in the notches 317 for preventing the lower part 32 from rotating

relative to the upper core part 31. Therefore, the lower core part (the engaging member) 32 is rotatable together with the upper core part (the actuating member) 31. In other words, the lower core part 32 is

immovable relative to the upper core part 31 in the rotating direction but movable in the direction perpendicular to the rotating direction, i.e., the

direction perpendicular to the second engagement face 320. The swivel

312 further provides an opening 316 in the lateral wall thereof. The opening 316 connects the room 111 of the upper cover 11 and the cavity

313 between the upper and lower core parts 31 and 32 once in assembly.

[0024] On the second engagement face 320, there are a selecting groove 321, a gathering groove 323 and an exit groove 325 which communicates with the gathering groove 323. The selecting groove 321 functions as a connecting structure for connecting the selected stream outlet 122 and one of the gas inlets 121. In assembly, one end of the selecting groove 321 is always aligned with the selected steam outlet 122 on the first engagement face 120, and the other end can be respectively aligned with each of the gas inlets 121 with rotating of the core 3. Therefore, by rotating the core 3, the valve is able to select any one stream from the gas inlets 121 and guide it to the selected stream outlet

122 for outputting. The gathering groove 323 functions as a connecting

structure for connecting and gathering all the unselected gas inlets 121 and guiding them to the room 111 in the upper cover 11 via the exit

groove 325. Gases in the room 111 may enter the cavity 313 either through the notches 317 or through the opening 316.

[0025] In one embodiment, the upper cover 11 is formed with a balance fluid port 115 connecting the room 111 to an outside of the enclosure room 111. The port 115 may serve as a balance fluid inlet for introducing an external fluid into the room 111 as a balance fluid, or may serve as a balance fluid outlet for outputting a balance fluid introduced from the gas inlets 121 of the first engagement face 120, which is referred to as an inner fluid hereafter for distinguishing from the external fluid.

The pressure of the fluid in the room 111 can be controlled by a pressure controller connected to the port 115. The pressure controller may control the pressure of the balance fluid in the room 111 to be higher or lower than, and preferably, approximately equal to that of the gases inputted by the gas inlets 121 of the first engagement face 120 which exert forces on the second engagement face 320. Though there is no restriction as to the absolute value of the pressure of the balance fluid which may be adjusted depending on the pressure on the second engagement face 320, it is usually higher than atmospheric pressure in actual implementation.

[0026] Therefore, a balance fluid passage is formed to lead a balance

fluid to the pressure balance face 30 or to an element closely attached on the pressure balance face 30, such as the washer 34 as shown in Fig. 1. In one embodiment, a balance fluid passage for leading an inner fluid as a balance fluid includes the gathering groove 323, the exit groove 325, the room 111, the notches 317 or the opening 316, and the cavity 313. In one embodiment, a balance fluid passage for introducing an external fluid as a balance fluid includes the room 111, the notches 317 or the opening 316, and the cavity 313, and communicates with the ports 115.

[0027] There is no restriction as to the shape or form of the connecting structures for connecting the ports (gas inlets 121 or selected stream outlet 122) on the first engagement face 120. For instance, as shown in Fig. 3, the connecting structure for connecting the selected stream outlet

122 and one of the gas inlets 121 may selectively be a hole, a slot or the like 321a defined within the lower core part 32a with two end ports 321 Ia and 3212a exposed on the second engagement face 320a.

[0028] Fig. 4 illustrates another kind of selector valve which selects one gas stream from a plurality of gas inlets, outputs it through a selected stream outlet, and plugs up the other unselected gas inlets. The valve defines only a selecting groove 321b on the second engagement face 320b thereof. One end of the selecting groove 321b is always aligned with the selected stream outlet 122b on the first engagement face and the other end can be respectively aligned with each of the gas inlets 121b through

rotations of the core, thereby the valve is able to select any one stream from the gas inlets by rotating the core and guide it to the selected stream outlet for being outputted. However, there is no groove or passage for gathering and outputting the unselected streams and the gas inlets of the unselected streams are directly stoppered by the second engagement face. The structures of other parts/elements may be similar to those shown in Figs. 1 and 2.

[0029] In one embodiment, there are only one gas inlet and one selected stream outlet on the first engagement face 120b, by rotating the core, the valve defines two engagement states of the gas inlet and the selected stream outlet—a connected state and an unconnected state. Thus it can be used as a switch valve capable of switching between an open

state and a closed state.

[0030] Fig. 5 illustrates a switch valve capable of switching between two states for altering the flow path and direction of a fluid. The switch valve has three inlets 123, 125 and 127 and three outlets 124, 126 and 128 on the first engagement face 120c thereof and has three connecting grooves 322c on the second engagement face 320c thereof. Through rotating the core, the switch valve is switchable between a first state as shown in Fig. 6 and a second state as shown in Fig. 7.

[0031] For the valves as shown in Figs. 4 and 5, no inner fluid is leaded to the pressure balance face as a balance fluid, therefore an

external fluid may be introduced as a balance fluid.

[0032] In the aforementioned valves, the two-piece core also can be replaced with an integral one comprising a shaft and an engaging member

integrally formed on one end of the shaft. For an integral core, the upper surface of the engaging member, or any other surface opposite to the second engagement face on the engaging member may serve as the pressure balance face.

[0033] There is no limitation for the shape and the position of the elastic member. The elastic member also can be springs other than disc springs, such as coiled springs, flat springs, volute springs, wave springs, ring springs, spiral power springs and spring pads, or any other elastic element which can provide an elastic force, such as an elastic block or the like. The elastic member can be disposed between the core and the valve body with one end thereof abutting on the valve body and the other end thereof abutting on the core, or even can be disposed outside the valve body.

[0034] The first and second engagement faces may be flat planes or curved surfaces such as truncated cone shaped surfaces.

[0035] The pressure balance face may or may not be parallel to the second engagement face. For example, the core can be a cone with the bottom surface thereof serving as the second engagement face and the cone shaped peripheral surface thereof serving as the pressure balance

face.

[0036] There are different modes for actuating the core to rotate, for example, manual, pneumatic, electrical or other mode, and as the drive modes are well known techniques in many fields, here it is unnecessary to give further details about them.

[0037] Materials suitable for manufacturing the valve body and the core in the present embodiments include any that can withstand the temperature, pressure and chemicals, such as acids, bases, or other reactive compounds, for use in the valves of the present invention. Examples of said materials include metals and their alloys, including but not limited to various grades of steel and stainless steel, super alloys, engineering plastics, ceramics, composite materials, polymers, or a combination of any of the foregoing. The first engagement face may be specially treated, for example, treated by nitriding and rubbing to enhance planarity and wear resistance. Particularly, the second engagement face may be made from heat-resistant and wear-resistant materials in order to achieve a better sealing effect with the first engagement face. These materials include, but are not limited to, modified polyimide, modified polytetrafluorothylene (PTFE), modified fluororubber (FKM), modified graphite, copper or bronzer. For instance, the second engagement face may be made from modified polyimide material (e.g., if the core is of two-piece structure, the whole lower core part can be made of modified

polyimide material), and therefore is capable of withstanding high temperatures above 200 degrees C for a long time, and of ensuring a wonderful sealing effect even under high temperature work conditions.

[0038] While the present invention has been illustrated and described with reference to some preferred embodiments, the present invention is not limited to these. Those skilled in the art should recognize that various variations and modifications can be made without departing from the spirit and scope of the present invention as defined by the accompanying claims.