US2241573A - Gauge valve - Google Patents

Description

y 1941. E. L. ASCHENBACH 2,241,573

GAUGE VALVE Filed July 15, 1938 11 mm H Z I Z LMIIIIIII gm mm 5/ MMW WNW

Patented May 13, 1941 GAUGE VALVE Emerson L. Aschenbach, Sellersville, Pa., assignor to United States Gauge Company, New York, N. Y., a corporation of Pennsylvania Appiication July 15, 1938, Serial No; 219,442

5 Claims.

This invention relates to pressure operated valves and more particularly to pressure operated valves designed to protect fluid pressure operated devices such as gauges or the like when used with systems of fluid under pressure that are subject to rapid fluctuations in pressure beyond the range for which the pressure operated devices are designed.

Gauge valves for protecting fluid pressure gauges against abnormal fluctuations in pressure which might arise in the system with which they are used have been used heretofore. One type of these prior art gauges provides a pressure responsive valve member in a recess in the gauge stem which substantially floats in the.

The valve described in the above named patent has been found quite suitable when used with normal or relatively high pressure systems. Recently, however, low pressure gauges have been developed for practical use, and it has been necessary to develop a check valve which will.

protect these low pressure gauges against abnormal pressures. An example of these recently developed low pressure gauges is a diaphragm type gauge for measuring pressures down to 5 inches of water.

When the valve disclosed in the above mentioned patent was used in these low pressure gauges, its operation was generally unsatisfactory in that its closing action was usually too slow to prevent pressures'beyond the range of 1 the gauge from being transmitted through the valve and causing injury to the gauge. It was, therefore, necessary to redesign this valve for use with low pressure gauges.

With the above pointed out defects of the prior art in mind it is a major object of the present invention to provide a novel valve, designed especially for use with a relatively low pressure gauge, for automatically and rapidly checking abnormal pressures-which are beyond the range for which the gauge is designed.

A further object of the present invention is to provide a novel pressure responsive valve, designed especially for use with low pressure gauges, which is simple in construction and easy to manufacture and assemble. The valve may be mounted in the stem of the pressure gauge or may be supplied in a separate fitting for attachment to existing installations.

A further object of the present invention is to provide a valve for low pressure gauges in which a pressure responsive valve member is mounted for movement in a pressure chamber of such novel design as to cause any changes in pressure in the system being measured to be immediately operatively effective upon the valve member.

Still a further object of the invention is to provide a novel check valve for use with a gauge or the like in which a generally cup-shaped valve member is arranged in a fluid pressure chamber with its open end facing the source of pressure, and the fluid containing space within the cup is materially reduced so that sudden changes in pressure from the source may be more rapidly effective upon the valve member. Specifically, a block of solid material of substantial volume is mounted upon a ring which retains the valve member in the chamber and the block projects into the interior of the cup.

Further objects of the invention will become apparent as the description proceeds in connection with the annexed drawing and the appended claims.

Figure l of the drawing illustrates an embodiment of the invention wherein the check .valve, illustrated partly in section, is mounted in an adapter which is fastened to the stem of a pressure gauge.

Figure 2 illustrates another embodiment of the invention wherein the check valve may be mounted in an adapter for attachment to the stem of a pressure gauge or may be directly incorporated in the gauge stem.

Referring to the drawing in Figure 1, an adapter H. is provided with a nut-like. enlarged headed portion l2 at one end for attachment to a threaded gauge stem I 3 leading to a suitable pressure responsive element (not shown) within gauge M. Headed portion I2 is internally threaded to cooperate with the gauge stem and its external surface is shaped to be manipulated by a wrench or similar tool. Gauge I4 is a low pressure gauge and may be of the type capable of measuring pressures as low as 15 inches of water above'described. Although the invention is illustrated and described for use with a gauge, it wfll be understood that it can be used for the protection of any low pressure responsive instrument or device.

At its lower end, adapter H is formed with an externally threaded extension l of reduced cross-section which is slightly tapered to facilitate assembly of the stem with a suitable cooperating fitting on a line leading to the system of fluid pressure to be measured.

Adapter II is formed with a central bore l6 which terminates at the lower end of extension l5 in a relatively deep recess I! which is concentric with bore 16 and preferably of larger diameter than bore l6. At the bottom of recess I! is formed a ridge l8 which is preferably concentric with bore l6 and provides a valve'seat for cooperating with a valve member l9 disposed in recess Il.

Valve member I9 is preferably. formed as a generally cylindrical cup and is preferably made by die shaping or some imilar operation from sheet metal so that it is extremely light in weight and inexpensive to manufacture. Valve member I9 is positioned in recess 11 with its open end facing away from bore [6, and a washer or gasket 2|, made of cork or some similar resilient material-is secured upon the outside of the bottom surface of cup l9 by a rivet 22 or some other suitable fastening means.

Cup I9 is retained in recess I! by an annular ring 23 which fits within a suitable groove 24 formed in the walls of recess l1 adjacent the lower end of the stem. Preferably ring 23 is rigidly and securely held upon the stem by peening over the lower edge 25 of extension l5 after the ring has been inserted in groove 24. Ring 23 is provided with an upstanding substantially annular collar formation 26 which extends a substanti'al distance within the space enclosed by cup l9 and occupies a material part of that space so as to reduce the space available for fluid within the cup for a purpose to be later described.

A slight clearance, designated at 21 is provided between the outer peripheral surface of collar 26 and the inner peripheral surface of cup IS. A slight clearance, designated at 2B is also provided between the outer peripheral surface of cup l9 and the inner peripheral wall of recess 17. These clearances are usually in the order of a few thousandths of an inch and are provided for a purpose to be described later. The inner periphery of collar 26 defines a bore 29 for leading fluid under pressure into the interior of cup l9.

In operation, gauge I4 with the adapter attached is connected to the system whose pressure is to be measured by coupling the threaded extension l5 to a suitable cooperating fitting at that system. .Fluid under pressure from the system then flows through bore 29 into the interior of cup l9. At pressures within the range for which the gauge is designed the cup-shaped valve element is lifted and probably tilted slightly so that at least part of its inner edge is lifted out of engagement with retaining ring 23. In this manner the fluid under pressure can flow through clearance 21, around the lower lifted edge of cup l9 and up along clearance 28 toward the bottom of the recess where'it enters bore l6 and is transmitted to the flexible pressure responsive diaphragm of the gauge.

The above described clearances permit a slight tipping of cup l9 but it may be said that the valve member substantially floats in valve open position when subjected to pressures within the range of the gauge and these pressures are not suflicient to lift'cup 19 high enough to contact .tween bores 26 and 16.

explosion or backfire at a gas burner, this increased abnormal pressure is built up within cup l9 which is forced upwardly in such a manner as to contact gasket 2| firmly upon valve seat l8 and thereby seal off bore l6 against the admission of fluids at the increased pressure.

Valve member I9 is very light and moves relatively rapidly to effect the above described valve closing action. However, during the period between the time when the increased pressure starts to build up within the cup and the time of firm engagement of gasket 2| on valve seat l8, some increase in pressure is transmitted past the edge of the cup and through the clearances and bore I6 to the gauge despite the long fluid path be- With high pressure gauges, this transmitted increase in pressure is usually within the designed range of the gauge and does no harm, but where low" pressure gauges are used this slight increase in absolute pressure may constitute a large increment of the designed range of the gauge and may cause injury to the delicate mechanism of the low pressure gauge.

In the present invention the speed with which valve member l9 seals off bore I6 is relatively high because projection 26 occupies a material portion of the volumetric space within the cup. thereby reducing the space available for fluid under pressure and permitting any abnormal increase in pressure in the system to be almost immediately built up within cup I9. This speedy response of valve member H! to close the valve reduces the time during which increases in pressure may be transmitted past the valve seat and consequently renders the absolute value of the pressure increase much less than it would be if the cup were substantially empty as in the above named patent.

Projection 26 may be of any desired shape and may even comprise a closed hollow body. The proportion of the volumetric space to be taken up by projection 26 is determined by the pressure range of the gauge with which it is used, projections of large volume being used with the lower pressure range gauges. A distinct advantage of shaping the projection 26 as an annular collar as described is that the cup is guided for substantially straight line movement toward the valve seat by the cooperating walls of the recess l1 and collar 26.

When pressure in the system returns to normal, cup is drops away from the valve seat and once more is floating supported in the recess I? to permit normal operation of the gauge.

The form of the invention illustrated in Figure 2 is designed for use with higher pressure gauges than that shown in Figure 1. Fitting i! may comprise an adapter or any suitable conduit leading to the gauge, or may be the gauge stem itself. It will be noted that projection 26' of Figure 2 occupies a smaller proportion of the interior of valve cup l9 than the corresponding projection 26 of Figure 1. This would indicate that the fitting illustrated in Figure 2 is meant to be used in a system whose pressure is slightly higher than that of Figure 1.

The retainer elements comprising ring 23 and projections 26 or 26' are preferably made from the same sized integral blanks with the central opening through each element being drilled of suitable diameter for a desired pressure range.

It is also within the scope of the present invention to provide projection 26 upon a member separate from stem II or fitting II but projecting into the interior of cup I9. In such a member, projection 26 would extend through an aperture in ring 23 and be supported, preferably integrally, by an annular washer clamped against the lower edge 25 of extension by the fitting to which the gauge stem is attached.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. In a check valve assembly, a valve housing having a longitudinal bore terminating in a pressure chamber of larger diameter than said bore, a generally cup-shaped valve member in said chamber with its open end facing away from said bore and having a closed bottom, a valve seat at one end of said chamber surrounding said bore and adapted to cooperate with the bottom of said valve member, means rigid with said housing for peripherally supporting and retaining said valve member in said chamber and means comprising a thick-walled substantially annular member of substantial volume projecting within the space enclosed by said valve member, the top of said annular member being spaced from the inner bottom surface of said valve member at all times.

2. In the valve assembly of claim 1, said annular member being formed integrally with said retaining means.

3. For use with a low pressure gauge, a check valve assembly comprising a casing provided with a longitudinal bore and an open ended generally cylindrical recess at one end larger than said bore and communicating therewith, a freely floating cup-shaped valve of generally cylindrical shape in said recess with its open end facing the open end of said recess, the closed end of said valve being adapted to cooperate with avalve seat in said recess surrounding said bore, a retainer mounted adjacent the open end of said recess for supporting said valve in said recess and a thick cylindrical projection occupying considerable volume integral with said retainer and extending upwardly into the interior of said cupshaped valve so as to occupy a substantial volume of the space therein, said retainer and projection being provided with a bore for admitting fluid under pressure into the interior of said valve and the lateral walls of said valve being spaced from said projection and the walls of said recess sufiiciently to permit passage of said fluid under pressure as the valve is maintained in substantially floating condition in said chamber.

4. A check valve for automatically preventing abnormal pressures from reaching a low pressure gauge or the like comprising a conduit having a bore; a chamber in said conduit into which said bore opens; a thin-walled cup-shaped cylindrical valve element in said chamber with its open end facing away from said bore and being movable in response to fluid pressure to seal 01f said bore from said chamber; a retainer ring for peripherially supporting said valve element within said chamber and a thick annular member on said ring concentric with said valve element and occupying a large portion of the volumetric space enclosed thereby, the upper edge of said annular member terminating in spaced relation to the inner bottom wall of said valve element and said annular member serving as a conduit for leading fluid under pressure to the interior of said valve member.

5. A check valve comprising a casing provided with a bore and a cylindrical chamber communicating at one end with said bore; a cylindrical member closing the other end of said chamber, said member having an axial passage to provide an inlet, and being nested concentrically within said chamber in spaced relationship to the side walls of and to said one end of said chamber to provide a deep cup-shaped space within said casing; a freely floating lightweight cylindrical cupshaped valve in said space with its side walls having a small clearance with the side walls of both said casing and said cylindrical member to provide a restricted passageway between said inlet and said bore, said cup having slightly less depth than said cup-shaped space whereby it has a small axial travel therein; and a seat for said valve adjacent said one end of said cylindrical chamber for closing communication between said chamber and bore when said valve is seated thereon.

EMERSON L. ASCHENBACH.

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