In line flow control components and systems

An in-line flow control component includes a body having an inlet and an outlet that are substantially coaxial with a tube extending through the body. The tube forms a flow path between the inlet and the outlet, and one end of the tube sealingly engages a valve seat for controlling fluid flow between the inlet and outlet. First and second diaphragms each have an opening sealingly secured about an outer periphery of the tube and an outer peripheral portion sealed to the body. The diaphragms selectively move the tube between open and closed positions in response to force acting on the diaphragms. The force is provided by either a mechanical mechanism (toggle, wedge member, threaded adjustment knob, etc.) or fluid pressure introduced between the diaphragms. The diaphragms may be similarly or differently dimensioned. Plural flow control components may be assembled in end-to-end sealed relationship.

FIELD OF THE DISCLOSURE

This disclosure relates in general to flow control components such as valves, fittings and regulators used in fluid systems, and more particularly, the disclosure relates to gas distribution systems for use in high purity fluid systems and corrosive fluid systems used to manufacture semiconductor wafers.

BACKGROUND OF THE DISCLOSURE

To manufacture semiconductors the industry uses a variety of high purity gases. These gases are controlled by systems made up of high purity valves, regulators, filters and other components. These components are connected together by either high purity metal seal fittings, by tube welding, or by bolting the components to manifolds using high purity metal seals. These connections are undesirable in most applications because they add additional time, cost and add unnecessary space between components.

SUMMARY OF THE DISCLOSURE

An in-line flow control component includes a body having an inlet and an outlet substantially coaxial with a tube extending through the body. The tube forms a flow path between the inlet and the outlet, one end of the tube sealingly engaging a valve seat for controlling fluid flow between the inlet and outlet. A first diaphragm has an opening sealingly secured to an outer periphery of the tube and sealed about an outer peripheral portion to the body. The first diaphragm selectively moves the tube between open and closed positions in response to force acting on the first diaphragm.

The in-line flow control component further includes a second diaphragm having an opening sealingly secured to an outer periphery of the tube, and sealed about an outer peripheral portion to the body at a location spaced from the first diaphragm.

The first and second diaphragms are axially spaced along the tube, and a space therebetween is sealed from fluid flowing through the tube.

In one preferred embodiment, a mechanical mechanism includes a wedge assembly for selectively moving the tube.

In another embodiment, fluid pressure is introduced to an area between the first and second diaphragms for selectively moving the tube.

A spring urges the tube toward one of an open or closed position.

The first and second diaphragms are substantially the same dimension, or in an alternate arrangement are different dimensions and thereby a greater force results on the diaphragm with the larger surface area and moves the tube.

Hence, a modular gas system that does not require high purity metal seal fittings, tube to tube welding, or expensive manifolds would be very desirable. This disclosure shows how this can be accomplished if the various components are redesigned to an in-line flow path configuration. This configuration allows the components to be coupled together in a fashion that not only eliminates the fittings, welding, or manifolds but in most situations will eliminate the inlet and outlet housings of the components as well.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

What is common in the designs ofFIGS. 1A, 2A, 3A, 4A and 5Ais that these known embodiments have a body with right angle flow paths and use a single diaphragm. This diaphragm is secured to the body along a circumference of the diaphragm so that the diaphragm contains fluid within the component. The diaphragm also provides a flexible member or means to control a valve mechanism inside the components body of the component with a mechanical member or means located outside the body of the component.

What is common in the designs ofFIGS. 2B-2J, 3B-3J, 4B-4G, 5B-5Q, 6, 7A-7E, 8A-E, and9is the use of two diaphragms with holes through the center. These diaphragms are centered in the body, are positioned perpendicular to the flow path with their through holes aligned, and there is a space between them. A tube is welded between the holes in the diaphragms making a leak tight passageway through the center of the diaphragms. These diaphragms are clamped between the body parts at the outer circumference of the diaphragms and the diaphragms can flex in a parallel motion allowing the center flow tube to move back and forth in a lateral direction. A flat lateral force spring is used to urge the tube in the desired direction. A mechanism to adjust or shut off flow is located at one end of the flow tube. When this mechanism is pressed against a valve seat, flow through the component is stopped. The diaphragms have a soft metal or plastic injection molded around the circumference to make a seal to the body parts. In these drawings the seams between body parts will be welded creating a high integrity leak tight system. The body parts could also be bolted or screwed together as will be appreciated by one skilled in the art.

Toggle Valve

FIG. 1Ashows a typical high purity toggle valve. A spring and toggle stem arrangement exterior to the flow path provide the mechanical force to push or release the diaphragm against the valve seat. High purity fittings are welded to the body to connect the valve to another component or fluid source.

FIGS. 1B-Gshow a high purity toggle valve100with an in-line flow path, i.e, a first opening or an inlet102and a second opening or outlet104in body portions106a,106bare aligned along a common longitudinal axis on opposite ends of a central body portion106cand the fluid passes through the body106near or adjacent the longitudinal axis. In a space110in body portion106cbetween axially spaced diaphragms112,114a toggle stem120, spring122and wedge mechanism124provide an actuating assembly130or to flex the substantially same-sized diaphragms112,114and to move hollow tube132that is connected to move with the diaphragms in a lateral direction pushing shut off seal134against seat136. Thus, a passage138through the tube is in constant communication with opening(s)140that communicate through the tube wall at a location between the seal134and the first diaphragm112. A flat lateral force spring150is located adjacent the other end of the tube and urges the seal134away from the seat132so when the toggle lever120is lifted the valve100will open and inlet102is in fluid communication with outlet104via the tube132. When the lever is actuated or depressed, the seal is urged toward the valve seat132and the force of the flat spring150is overcome thereby closing communication between the inlet and outlet.

Advantageously, the actuating assembly130, comprised of a lower portion of the toggle stem120, the spring122, and the wedge mechanism124, is located in a sealed location between the diaphragms112,114. The wedge mechanism includes two components in this embodiment ofFIGS. 1B-1D, namely, a first wedge component124athat is generally shaped as a partial conical member about the tube132and a second wedge component124bextending from a lower portion of the toggle stem120for engagement with the first wedge component. The relative sliding engagement of these first and second wedge components relative to one another in response to movement of the toggle, laterally moves the tube and diaphragms located adjacent opposite ends of the tube between open and closed positions.

FIGS. 1E-Gshow another way of creating the lateral movement necessary to open and close the valve by using a three wedged washer design124c,124d,124e. The center washer124eis moved in a vertical motion forcing the two outer washers124c,124dto move in a lateral or horizontal direction. In substantially all other respects, the embodiment ofFIGS. 1E-1Gis structurally and functionally similar toFIGS. 1B-1D.

Pneumatic Valve

FIG. 2Ashows a typical high purity pneumatic valve. A spring loaded plunger pushes the diaphragm against a valve seat. The plunger is urged away from the valve seat by pneumatic driven pistons.

FIGS. 2B-Dshows one version of a high purity in-line flow path pneumatic valve200. Where possible, like elements will be identified by like reference numerals in the200series. Like the toggle valve100above there is a tube232which has diaphragms212,214with holes through the center welded to each end of the tube. Unlike the toggle valve, this pneumatic valve design has one diaphragm214with a larger outer diameter than the other diaphragm212and therefore the second diaphragm214has a larger surface area. The flat lateral force spring250is used to urge the flow tube232and valve shut off seal234to the closed position. A flow passage252through the outer body housing is located between the diaphragms to provide pneumatic pressure. When the space or210area between the diaphragms212,214is pressurized, the force created on the larger diaphragm214is greater than that on the smaller diaphragm212causing the flow tube232and valve234to shift to the open position. A normally open valve could be made by locating the valve mechanism to the other end of the tube.

FIGS. 2E-Gshows another version of a high purity in-line flow path pneumatic valve200that might be used in high pressure systems. In this design the two diaphragms212,214can be of substantially equal diameter. Between the diaphragms one or more pistons254are slid over the flow tube and a stationary plate256is positioned adjacent to each piston254. The pistons254and stationary plates256have o-ring seals258on the inner and outer diameters. A flow passage252a,252bthrough the body206is located between each piston and stationary plate. A mechanism or means260to connect a pneumatic source to these flow passages is located on the outside of the valve. Pneumatic pressure applied between the respective stationary plates and the pistons, urges the pistons to move in opposite directions. Steps262in the valve body prevent the stationary plate from moving, steps264on the flow tube232cause the piston movement to be transferred to tube and valve mechanism234opening the valve200. This embodiment also illustrates that the seal member234can be disposed adjacent the outlet204as an alternative to the previous embodiments which show sealing with the valve seat adjacent the inlet.

FIGS. 2H-Jshows the same valve described inFIGS. 2B-Dexcept with an alternative valve mechanism. In this design the shut off seal266is again located downstream of diaphragms212,214which may be more desirable in some situations, and is also secured in a C-shaped clip that engages the valve body at a central location positioned radially inward of angled flow passages extending inwardly from the outlet204. However, one skilled in the art will recognize that the seal member could alternately be located on the body for selective engagement with the tube end that would define the valve seat if so desired.

FIG. 3Ashows a typical high purity adjustable valve. In this design there is a threaded valve stem that can be rotated to adjust the movement of the diaphragm and therefore the valve opening.

FIGS. 3B-Dshows a high purity in-line flow path valve300similar to the toggle valve ofFIGS. 1B-1Dabove except that the toggle stem and handle are replaced by a threaded valve stem366. Again, for purposes of brevity and consistency, where possible like elements will be identified by like reference numerals in the300series. Unlike the toggle lever that moves the stem to full open in one quick motion the threaded valve stem366allows this movement made in precise increments adjusting the flow rate.

FIGS. 3E-Gshows another version of an in-line flow path high purity adjustable valve300. In the space between the diaphragms312,314there is an adjustment knob368mounted outside the valve body306perpendicular to the flow path. This adjustment knob368drives a shaft370which rotates inside of the valve body. Attached to this shaft370is a bevel gear372which rotates a second mating bevel gear374positioned perpendicular to the first gear and whose rotational axis is parallel to the flow path. This second gear374has a threaded hole through the center and a matching threaded tube376inside. This threaded tube and gear surround the flow tube332located between the diaphragms312,314. As the adjustment knob368is rotated the threaded tube376moves in a parallel direction to the flow path. This lateral movement pushes on stops on the flow tube inside it causing it to adjust the valve opening.

FIGS. 3H-Jshows a three wedged washer design similar to the toggle valve shown inFIGS. 1E-G. Therefore, like reference numerals in the300series are similar in structure and function to that shown and described inFIGS. 1E-G.

Pressure Regulator

FIG. 4Ashows a typical pressure regulator which has a body with right angle flow paths and a single diaphragm. This design has been used for decades and how the illustrated pressure regulator ofFIG. 4Afunctions is well known. There is a mechanism to vary a spring force against one side of the diaphragm and the fluid pressure applies force to the other side. A valve responds to the movement of the diaphragm regulating the flow and pressure.

FIGS. 4B-Dshow an in-line flow path regulator design400. This pressure regulator design400is similar to the pneumatic valve200describe inFIGS. 2B-Dwhere one diaphragm414has a larger surface area than the other diaphragm412. Again, a valve mechanism434is located at one end of the tube432except this time the valve mechanism is configured to meter the flow as well as shut off flow completely. In the space between the diaphragms that is exterior to the flow stream, there is a mechanical mechanism or means (similar to those used inFIG. 3B-Dor3E-G) except this time the mechanical mechanism is used to adjust a spring force from spring478to urge the valve in the open position. As pressure inside the valve housing increases, the pressure will apply more force on the larger surface area diaphragm414and therefore will urge the tube432towards the valve seat436. Hence, as the force from the fluid pressure approaches the force of spring478, the valve will restrict and eventually shut off inlet402flow. Increasing the force of the spring478will require more force to close the valve resulting in a higher system pressure.

FIGS. 4E-Gshows another in-line flow path regulator design400that uses an external pressure source460between the diaphragms. This pressure will apply more force to the diaphragm414with the larger surface area which will urge the valve434to the open position until the valve is balanced by the process gas pressure. This is similar to what the industry refers to as a dome loaded regulator.

Purge Valve Assembly

Most semiconductor industry gas systems require a purge valve assembly which can shut off the process gas and introduce an inert gas such as nitrogen to purge the system during down times.FIG. 5Ashow a typical high purity purge valve assembly. This is actually two valves, one to turn off and on the process gas and one to turn off and on the purge gas. They are mounted into one body because it is desirable to have the purge gas enter the system as close as possible to the valve seat of the process gas.

FIGS. 5B-Dshows this valve arrangement redesigned to an in-line flow path configuration. The process gas is controlled by a pneumatic process valve500like the one described inFIGS. 2B-D. This process valve500is mated to an adaptor580which has a side port580for introducing the purge gas to the system. A purge valve500′ similar to the pneumatic valve ofFIGS. 2B-2Dis mated to this adaptor580however this purge valve500′ is installed in the opposite direction as the process valve500. This arrangement with the two valve seals534,534′ facing each other with only a thin web of steel582separating them is extremely desirable in a purge valve. There are also significant safety features inherent in this design. It is important in the purging procedure that there is enough purge gas pressure to prevent flow from going in the reverse direction when the valve is opened. By adjusting the pressures of the purge gas and the pneumatic gas, a situation can be set up where the pneumatic pressure cannot open the purge valve without the additional force from the purge gas pressure.

FIGS. 5E-Gillustrate another means to prevent reverse flow in the purge line by using the addition of a check valve584.FIGS. 5E-Gshow how a donut shaped plunger586having first and second O-ring seals588,590provided radially inwardly and radially outwardly, respectively, of where the side port passage terminates in the assembly and the plunger586can be installed within the purge valve500′ to prevent reverse flow.

FIGS. 5H-Jshow a purge valve500′ with yet another safety feature. This valve prevents the purge valve from being opened if the process gas valve has not been closed. This is accomplished by adding a third diaphragm588which is larger than the other two diaphragms512,514. To open this valve, pneumatic pressure is applied between the first two diaphragms (viewed left to fight in these figures), one being larger than the other causing it to function then same as the valve described inFIGS. 5B-D. The port590between the second and third diaphragms is a vent port that could possibly be monitored by a PC mounted transducer. The third diaphragm588is larger than the other two and is exposed to the process gas pressure on the downstream side, hence the third diaphragm prevents the purge gas from being opened unless the process gas pressure is reduced significantly below the pneumatic pressure.

FIGS. 5K-Nshow a method of making attachments to the pneumatic and purge ports using a saddle shaped block590which is attached to the system using the same bolts591that clamp the flow components together. The pneumatic gas can be attached to the saddle block590using any standard threaded fitting. The purge (high purity) gas can be connected using a standard microfit elbow592, one end593of one arm of the elbow is pressed against a soft seat594in a counter bore in the body, force is applied to the back of the elbow with a set screw595in the saddle.

FIGS. 5O-5Qshow another method of connecting to the purge port. In this design a tube596with a flange597is welded to one arm598of a microfit elbow and a split nut599is used to press the end of the tube against a seat.

Filter

Many filters already have inline flow paths.FIG. 6shows how they can be installed in an in-line flow systems by replacing the inlet and outlet body housings with a simple adaptor ring AR.

In Line Flow Systems

FIGS. 7 and 8show how these in-line flow path components can be combined to make very compact high purity gas systems.FIGS. 7A-7Cshow the combination of a toggle valve, a pressure regulator and a pneumatic valve. Inlet and outlet housings have been added to make connection to the system.FIG. 7Dshows the inlet and outlet housing made with an integral square configuration which allows room for bolt holes in the corners. Bolts can then be used to clamp the components together instead of welding.FIG. 7Eshows the same system but with flanges and bolts holding the components together.

FIGS. 8A and 8B and 8Cshow a system that combines seven components, a toggle valve, a pneumatic valve, a pressure regulator, an adjustment valve, a filter, a purge valve, and another pneumatic valve.FIG. 8Ashows these components with their inlet and outlet housings removed,8bshows them welded together.FIG. 8Dshows this seven component system in the bolted configuration with the pneumatic and purge connections.FIG. 8Ehas a printed circuit board PCB installed with mini pneumatic valves and pressure transducers. The adjustment and toggle handles can obviously be rotated to allow the saddle and PC board to span all the pneumatic and vent ports.

Check Valve

FIGS. 9A and 9Bshow how the check valve feature incorporated inFIG. 5E-Gcan be installed in a separate housing creating a three way check valve component. This component could be useful when mixing fluids down steam of the above systems.

The disclosure has been described with reference to the preferred embodiments. Modifications and alterations will occur to others upon reading and understanding this specification. It is intended to include all such modifications and alterations in so far as they come within the scope of the appended claims or the equivalents thereof.