Septum Valves

Abstract

Apparatus for containing fluids, i.e., liquids or gases, within a confined space. In one embodiment, the apparatus comprises a valve structure including a tubular member (with axial opening) which leads into an enclosed space which can contain fluid. A septum, and a stem, provided with a lateral opening therethrough, are integrally mounted or mounted in series. The stem is rotatably mounted within the wall of the tubular member for exposure of the septum to the valve exterior. Exposure of the septum in such manner permits injection or withdrawal of fluid from the enclosed space. In preferred embodiments, the septum is located within an axial opening through the valve stem and lies across the lateral opening of the stem to provide an effective leakproof seal. In other embodiments, the septum is contained within the tubular member in series with the stem. The valve, in all embodiment, is adaptable for use with containers of various types or for use in sample inlet systems, as conventionally used in modern analytical instruments.

Description

This invention relates to apparatus for containing fluids, i.e., liquids and gases, or both, within a confined space. In all combinations, the apparatus includes valves, with seal features, adapted especially for use in confining fluids until such time as it is desired to withdraw fluid from or inject other fluid into the confined space, e.g., a container or sample inlet system such as is widely used in modern analytical instruments.

Among the objects of this invention are:

To provide a valve which makes the confinement of even highly volatile fluids feasible, without adverse effect or change caused by the external environment.

To provide a valve not only effective for preventing such adverse effect or change, or loss of fluid from a confined space when closed, but yet effective even when the valve is opened, or used repeatedly, to permit withdrawal or injection of fluid into the space within which it is confined.

To provide unique valve container combinations by virtue of which even highly volatile fluids can be contained without adverse effect, change or loss of contents from the container, even after repeated usage, and wherein the fluid withdrawn therefrom is truly representative of that originally supplied to the container.

To provide unique valve sample inlet system combinations by virtue of which fluid specimens can be injected therein conveniently, easily and without loss of fluid.

To provide such valve container, and valve sample inlet combinations which are readily adapted for reuse by virtue of easily changeable septum portions.

To provide valves and valve combinations, the valve portions of which contain stems readily freely rotatable or movable without side thrust within the tubular portion of the valve, or body, and a valve which is compact and readily operated, without lubrication.

These and other objects will be apparent in view of the present invention which, in all embodiments, includes a valve structure comprising a body, or tubular member, which leads into a space wherein fluids can be confined, and which contains a septum and stem integrally mounted, or mounted in series. The stem, provided with a lateral opening therethrough, is rotatably mounted within the wall of the tubular member to provide a means for exposure of the septum to permit injection or withdrawal of fluid from the confined space. The valve, but for the presence of the septum, is thus opened and closed by alignment and misalignment of the lateral opening of the stem with the axial opening through the tubular member to expose the septum located adjacent the stem, or preferably within the stem itself. In either instance, the septum acts as a fluid impervious seal to maximize closure of the tubular member, even when the valve is open for fluid withdrawal or injection.

These and other features and advantages will be better understood by reference to the following detailed description and to the accompanying drawings to which reference is made in the description.

Referring to the drawings:

FIG. 1 is a side elevation view, in section, showing a preferred valve, and valve-container combination. The valve, shown in open position, is provided within a stem within which an easily changed septum is integrally mounted;

FIG. 2, a fragmentary view, is also a sectional side elevation view identical to the preceding figure except that the valve is shown in closed position; and

FIG. 3, also a fragmentary sectional side elevation view, is the same as FIG. 1 except that the septum has been punctured by the needle of a syringe for withdrawal of liquid contents from the container;

FIG. 4 depicts a valve generally similar, at least in part, to that described by reference to the preceding figures except that, in this instance, the valve is employed as a portion of a sample inlet system, e.g., as used on a G.C. column or mass spectrometer;

FIGS. 5 and 6 depict the sequence of simple steps involved in changing a septum as employed in the several apparatus combinations described in the foregoing figures;

FIGS. 7 and 8 depict valve portions wherein the septum is located adjacent, separate from, and in series with the stem.

Referring to the sequence represented by FIGS. 1-3, there is shown generally a preferred type of flanged valve 10 in combination with a container or bottle 26, filled to a level 25 with a volatile liquid composition.

The valve 10 is constructed of a body or tubular member formed by the enclosing wall 11, providing an axial opening 12 which leads into the vapor space above the liquid level 25. A stem 14, provided with a handle 17 and a lateral opening 15, is rotatably mounted within the transverse opening 13 of wall 11. The stem 14, in this embodiment, is also provided with an axial opening 18 within which is contained a plug septum 16 which lies across, seals off, blocks, or closes the transverse opening 15.

For use in valve-container combinations, the lower portion of the tubular member 11 is also provided with a flanged end portion containing a peripheral groove 23 within which rests a packing or O-ring 21. The O-ring 21 is pressed between the upper side 19 and the lower thin member 22, and pressure is maintained on the O-ring 21 by tightening down on the open centered cap or cover 24 which is threadably engaged to the top of the bottle 26. Thus, it is to be observed that the upper side 19 of the flanged member is pressed downward by the cap 24, and the O-ring 21 is compressed between member 19 and member 22, shown as an integral construction in this instance, which rests atop the upper rim 27 of bottle 26. In this fashion, the O-ring 21 is extruded or thrust outwardly and downwardly against the inside of the cap 24 and thin member 22, so that the latter presses against the rim 27 of bottle 26 to form an effective leakproof seal.

In the closed position of the valve 10 as shown by reference to the first figure, the fluid contents of the bottle 26 are maintained completely isolated from the external environment. Highly volatile fluids, and mixtures of such fluid components, will retain their original composition and condition without significant change as would be expected even when such fluids are loaded and contained in ordinary bottles or containers. Such high degree of isolation can even be maintained in accordance with the present invention, however, even after the bottles have been once opened, or repeatedly opened.

The structure which permits removal of contents from the bottle 26 without exposure to the atmosphere is further described by reference to FIGS. 2 and 3. Stem 14 is first rotated through a 90.degree. angle, by action on handle 17 as shown by specific reference to FIG. 1. The contents of the bottle 26 nonetheless remain protected from exposure to the atmosphere because of the presence of the septum 16. In this position of the valve stem, however, a needle syringe 20 can be passed through the septum 16 and into the liquid for withdrawal of a fluid specimen as shown in the third figure. The needle 20 can be withdrawn back through the septum which in itself tends to return to its original unstretched, unruptured position to minimize or prevent leakage of fluid from the bottle 26. Immediately after the withdrawal of fluid, the valve is again closed as again shown by reference to FIG. 2 to protect the fluid contents. This process can be repeated ad infinitum until the bottle 26 has been emptied. The elimination of changes brought about by entry of air into such containers, escape of highly volatile components as by diffusion and pressure increases, particularly as occurs after such bottles or containers are once opened, is striking. This is particularly important with regard to standard fluids used in highly accurate modern analytical instruments.

Valves of generally the same type can also be directly used in sample inlet systems of modern analytical instruments. This is shown by reference to FIG. 4 wherein a valve 30 is mounted upon a sample inlet system, represented by the enclosing wall 28. The sample inlet system is, in turn, provided with an optional carrier gas inlet formed by the enclosing wall 29. Rotation of the stem 34, to the position shown, via action upon handle 37 aligns the lateral opening 35 with the opening 32, formed by the enclosing section of wall 31, of the sample inlet system. The needle portion of a syringe (not shown), containing a measured fluid specimen, can be passed through the septum 36 and sample injected into the passageway where it is picked up by carrier gas fed into the inlet system via conduit 29. Escape of fluid is minimized, and essentially completely eliminated upon closure of valve 30. A unique feature of this embodiment for application to sample inlet systems is that the septum can be readily changed without disassembly of the sample inlet.

The simple technique by which septums can be changed in the embodiments represented by FIGS. 1 through 4, inclusively, is shown and described by reference to FIGS. 5 and 6. The plug septum 36 is thus pushed out of the opening 38 by action of the new replacement plug septum 36.sub.1 and cylindrical rod 9. When the septum 36 is extended from the opening 38, it is easily removed with the fingers and the cylindrical rod 9 is withdrawn, leaving the new septum 36.sub.1 in position.

The septum, if desired, can also be mounted in series separate and apart from the rotatable stem itself as shown, e.g., by reference to FIGS. 7 and 8. In these figures are thus shown rotatable stems 44, 54 mounted in tubular members 41, 51 such as may constitute the valve portion of a valve container or valve inlet system combination. In the former, the septum 46 is seated and held in place by an open centered extremely threaded member 45 which is engaged with an internally threaded counterbore contained within the top of member 41. In the latter the septum 56 is seated and held in place within a space provided in an internally threaded member 55, the threads of which mate with external threads on the member 51. In these embodiments it is apparent that the order of the stem and septum can be reversed, but preferably the septum components are located outwardly from the stem in the series. In passage of the needle through the septums, the stem is rotated to open the valve, and at all other times, as in changing the septums, the valves are closed.

The apparatus of the present invention can be constructed of essentially any material substantially inert to chemical or corrosive action by the fluid, or contained elements. The valve can be conveniently constructed of various metals, e.g., ferrous metals such as iron, iron alloys, steel, stainless steels, and the like; or e.g., glass, brass, copper, bronze, chrome, and the like. The materials can be solid or of laminar construction, and can be provided with a protective film, coated, plated, or the like, particularly those films known to be unreactive or impervious to known chemicals. Rigid and semirigid forms of plastics and plasticlike materials can also be employed, these materials being particularly desirable. The self-lubricated plastics are especially preferred in this capacity, and are also suitable for application in the form of protective films. The polyfluorinated ethylene polymers, notable among which is polytetrafluoroethylene (Teflon), are particularly outstanding.

The septums are constructed of conventional septum materials, resilient or elasticlike materials such as natural or synthetic rubber, gasket materials and the like.

It is apparent that various changes, such as in absolute or relative dimensions of the parts, materials used, and the like, as well as the suggested mode of withdrawing or delivering fluids, can be made without departing the spirit and scope of the invention, as will be apparent to those skilled in this art.

Claims

Having described the invention, what is claimed is:

1. A valve for containing fluids within a confined space comprising, in combination,

a tubular member formed by an enclosing wall providing an axial opening therethrough, the wall of said member also containing a lateral opening,

a septum which lies across, covers and seals the axial opening through the said tubular member,

a stem provided with a lateral opening therethrough rotatably mounted within the lateral opening in the wall of said tubular member

whereby rotation of said stem to align the lateral opening of the stem and the axial tubular opening provides access for withdrawal and injection of fluids by penetration of the septum, after which time misalignment of said openings closes the valve and limits such exposure for maximum confinement of the fluids within the confined space.

2. The apparatus of claim 1 wherein the septum is contained within an axial opening provided in the rotatable stem.

3. The apparatus of claim 1 wherein the septum and stem are in series.

4. The apparatus of claim 3 wherein the septum constitutes the outer member of the series.

5. The apparatus of claim 1 wherein the lower portion of the valve is flanged, the outer peripheral edge of the flange is recessed and contains an O-ring.

6. The apparatus of claim 5 wherein the O-ring is constructed of rubber.

7. The apparatus of claim 5 wherein a container is secured to the valve via an open-centered cap, the tubular portion of the valve being extended through the opening in the center of the cap, while the flanged portion is held in place atop the contained via threadable engagement between the cap and the top of the container, and whereby the downward pressure exerted by the cap causes extrusion of the O-ring against the internal surfaces of the cap and upon the lower portion of the flange to press the latter downwardly to seal the container.

8. The apparatus of claim 1 wherein the valve is provided within a sample inlet system.

9. The apparatus of claim 1 wherein the valve is constructed of a self-lubricating type of rigid plastic, with the exception of the septum which is of rubber.

10. The apparatus of claim 9 wherein the rigid plastic is Teflon.