US1951926A - Relief valve - Google Patents

Description

-'March 20, 1934. I K, s. M. DAVIDSCN 1,951,926

v RELIEF VALVE Filed July 1a, 1929 Inumr 715-7151986- K991112751. I

(M MAW M Patented Mar. 20, 1934 UNITED STATES PATENT OFFICE RELIEF VALVE setts Application July 13, 1929, Serial No. 377,968

2 Claims.

The present invention relates to valves for automatically relieving the.pressure within portable containers, such as containers employed for conveying liquefied petroleum gas.

it is desirable to provide in connection with such containers some form of relief which will prevent bursting of the container under abnormal pressure. Such a pressure may well result from the temporary and abnormal heating of the container, either during transportation or use. These containers have been provided with frangible seals designed to rupture under such pressure, and avoid bursting of the tank. However, devices of this character are relatively unsatisfactory due to the fact that rupture of the seal causes the contents of the tank to become empty, and may in addition cause the liberation of large quantities of a combustible or explosive medium when mixed with air.

The purpose of the present invention is to provide a simple and eiiicient device for relieving abnormal pressures in containers of this character which vents only a sufiicient amount of gas to relieve the pressure, and thereafter closes tightly and automatically to prevent escape of the bulk of the contents. The device may be readily inserted within a container, and when installed does not project therefrom in a manner to become easily broken or interfere with the convenient handling of the container.

The various features of the invention consist in certain novel constructions, combinations and arrangements of parts hereinafter described and claimed, the advantages of which will be obvious to those skilled in the art from the following description.

The accompanying drawing, illustrating the preferred form of the invention, is a sectional elevation of the improved device embodied in a container of the usual type.

As indicated in the drawing, the container 10, which may be provided with a boss 12, has threaded thereinto a valve body 14 having an external threaded portion which projects well within the container when mounted in position. The inner portion of the valve body is provided with a guide 16 for a valve stem 18, having a head 20 which is positioned within a chamber 22 formed within the' threaded portion of the valve body as indicated. The chamber has. communication with the interior of the container through an axial port 24 in free communication with transverse ports 26. The port 24 is normally closed by the valve- 20 which is maintained on its seat by a spring 28 surrounding the inner end of the valve stem and interposed between abutments 30 and 32. The abutment 30 is supported on the inner end of the guide member 16, and the cooperating abutment 32 is supported on an adjustable head 34 threadedly connected with the valve stem at 36 and maintained in adjusted position by a lock nut 38. Located beyond the valve 20 and normally hermetically sealing the chamber 22 is a frangible copperdisk 40 which is clamped within the valve body by a plug 44 which engages the frangible disk through interposed aluminum packing ring 46. In the normal condition of the device the contents of the container are hermetically sealed from the atmosphere through the frangible disk. However, the creation of an abnormal pressure within the container is sufficient to elevate the valve 20 and rupture the frangible disk, relieving the pressure. Venting a portion of the contents with consequent relief of pressure causes the valve 20 to be reseated, preventing further escape of contents from the container. In ordinary practice the 'valve 20 will be set to relieve at a lower pressure than the rupturing pressure of the disk.

With this type of construction the major portion of the valve and the operating mechanism are located within the container, the only projecting portion being the head of the valve body and the sealing plug. Furthermore, a ruptured disk may be replaced by removal of the plug without dismounting the valve from the container. When the device is in Working condition the valve and cooperating parts are sealed from dust and dirt by the frangible disk, and no opportunity is present for engagement of foreign material between the valve and seat or within the moving parts of the valve.

What is claimed is:

1. A relief valve for portable containers comprising a body portion adapted to be mounted in the container and having, a chamber and a passage affording communication between the inner end of the chamber and interior of the container, a spring-pressed valve normally closing the passage at the inner end of the chamber and wholly contained within the container, a frangible member detachably supported within the body at the outer end of the chamber, and a holding plug mounted within the outer end of the body and detachably retaining the frangible member in place, the plug being removable and the frangible member replaceable without dismantling the body from the container.

2. A relief valve for portable containers comprising an externally threaded body portion screwed into the container and her extending into the threaded a passage afiording the container, an outd valve mounted the chamber and arranged y within the container for sealing against ingress of air through the passage at the inner end of the chamber, and a frangible member hermetically sealing the outer,

end of the chamber beyond the valve and preventing access to the valve and seat and the chamber sealed by the frangible member.

KENNETH S. M. DAVIDSON.

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