US3307576A

US3307576A - Automatic dump valve

Info

Publication number: US3307576A
Application number: US358894A
Authority: US
Inventors: William A Himes; Alfred E Graham
Original assignee: Newport News Shipbuilding and Dry Dock Co
Current assignee: Newport News Shipbuilding and Dry Dock Co
Priority date: 1964-04-10
Filing date: 1964-04-10
Publication date: 1967-03-07
Anticipated expiration: 1984-03-07

Description

March 7, 1967 w. A. HIMES' ETAL 3,307,576

' 4 .AUTOMATIC DUMP VALVE Filed April 10, 1964 2 Shets-Sheet 1 INVENTORS wmmm AHMES 6b ALFRED EGFZHHHM I i /MA W ATTORNEYS March 7, 1967 w. A. HIMES ETAL AUTOMATIC'DUMP VALVE Filed April 10, 1964 2 Sheets-Sheet 3 FIG 6 M INVENTORS L \LHLUPM HHMES e fiLFRED E GRHHHM ATTORNEY5 3,307,576 AUTOMATIC DUMP VALVE William A. Himes and Alfred E. Graham, Newport News,

Va., assignors to Newport News Shipbuilding and Dry Dock Company, Newport News, Va., a corporation of Virginia Filed Apr. 10, 1%4, Ser. No. 358,894 8 Claims. ((31. 137-527.8)

The present invention relates to underwater mining, and more particularly to mining operations which are carried out at great depths beneath the surface of the water. The underwater mining operations contemplated in the present invention are particularly concerned with the mining and recovering of solid substances from the floors and subfloor regions of the sea.

The apparatus as illustrated in detail in the present application is also generally illustrated and described in copending US. patent application Serial No. 332,999 filed December 24, 1963 wherein the specific structure as illustrated in the instant application is shown in combination with other components employed in an over-all underwater mining operation.

While the apparatus of the present invention may be utilized in other applications, it is especially adapted for use in underwater mining operations for recovering materials such as manganese nodules or other solid materials which generally are present at depths from about 400 feet to 12,000 feet or more beneath the surface of the sea.

It is accordingly apparent that the apparatus must be capable of operation at great depths and under very high pressures when submerged to the necessary operating depths in this type of operation.

This type of mining operation is carried out from a ship which moves along the surface with a hollow conduit means or pipe means suspended therefrom in a generally vertical direction and having a suitable collecting means at the lower end thereof for sweeping or traversing a particular area of the sea bottom and collecting the desired material. This material is then suitably raised to the ship as by the utilization of pumping means which produces movement of a stream of liquid from the collecting means to the ship of suflicient velocity to entrain the solid material and carry the solid material to the ship.

For certain important and practical purposes, the pumping means is positioned at an intermediate point in the conduit means between the collecting means and the ship.

The solid material to be collected and raised by the mining apparatus of the present invention may be of substantial size and weight, and in a typical example where manganese nodules are concerned, the solid nodules collected according to the present invention are generally spherical in configuration and may range in size up to about 8 inches in diameter with a specific gravity of approximately 2. Although such nodules occur in larger sizes, it is anticipated that mining of such nodules up to the size of about 8 inches in diameter may prove to be the most economical and efiicient arrangement. In any event, it is apparent that the size of the mining equipment must be on a grand scale to accommodate a large volume of relatively big solid particles, and the conduit means must be of a size to allow these large numbers of solid particles to readily pass therethrough. In a typical example, the conduit means may have an inner diameter of about 19 inches.

On occasion, the flow of liquid within the conduit means may be interrupted due to one or more causes. For example, the solid particles may become temporarily jammed within the conduit means or so numerous and close to one another at some location therein so as to substantially block up or obstruct the interior of the conduit means. On the other hand, the pumping means may fail,

J United States Patent assists Patented Mar. 7, 1967 thereby causing the liquid stream to cease its upward movement. Upon such interruption of the liquid flow in an upward direction, the solid particles within the conduit means will tend to drop downwardly relative to the liquid in the conduit means under the influence of gravity. It is apparent that if all the particles were to drop down and accumulate on one another from a substantial length of the conduit means which may extend for many thousands of feet, the tremendous mass and concentration of such accumulated particles would be such that it would be impossible from a practical standpoint to again get the liquid stream moving with sufficient velocity to re-entrain the solid particles and move them upwardly within the conduit means to the ship.

It accordingly is necessary to provide suitable dump valve means which is closed during normal operation of the mining equipment and which upon interruption of the liquid flow in the conduit means automatically opens and is positioned so as to cause solid particles dropping downwardly within the conduit means to be discharged out of the conduit means to prevent accumulation thereof at the lower portion of the conduit means.

The automatic dump valve apparatus of the present invention must be of such construction so as to operate efliciently at great depths beneath the surface of the water at high pressures, and under various sea condition-s. At the same time, there exists a relatively small pressure differential between the inside and the outside of the conduit means, and accordingly, on opposite sides of the dump valve means. The dump valve means must therefore be so arranged as to remain substantially closed at all times during normal operation when such small difierential pressures exist thereon, and yet the dump valve apparatus must open substantially immediately upon change or drop in pressure Within the conduit means. The pressure on the outside of the conduit means and dump valve remains substantially constant as determined by the depth and relative movement of the apparatus through the water. The pressure on the inside of the conduit means is also substantially constant during normal operation of the mining apparatus, but this internal pressure within the conduit means may change from time to time under certain circumstances as discussed above.

The present invention is directed to automatic dump valve apparatus for use in the pressure pumping line of under-water mining equipment, or in other words, the dump valve apparatus disclosed herein is utilized in the pressure pumping line extending from the pumping means upwardly to the ship, this line being under constant internal pressure when the pumping means is operating or when the conduit means is not clogged or jammed for one or more reasons. The pumping apparatus is of such a size and nature that the pressure of the liquid flowing through the pressure pumping line is greater than the ambient pressure of the surrounding water so that the internal pressure of the liquid within the conduit means normally urges the valve means of the present invention to its closed position. Upon interruption of the liquid pressure within the conduit means, the valve means automatically moves from its closed position to its open position whereby it will deflect any downwardly falling solid particles within the pressure pumping line through a lateral opening of the apparatus and outwardly of the conduit means whereby the solid particles can not accumulate within the conduit means. At the same time, the valve means of the present invention moves into an open position which permits free communication between the conduit means below the dump valve apparatus and the surrounding water.

The valve means of the present invention also has a slight clearance with-the edges of the wall portion which define the opening in the conduit means, and means must be provided for providing an effective seal between the valve means and the surrounding opening defining portions of the wall of the conduit means such that the required pressure differential will act upon the valve means to maintain it closed during normal operation of the mining apparatus.

While the seal described and claimed herein is referred to as a fluid-tight seal it should be understood that a slight amount of leakage is permissible which would serve to reduce the efficiency of the apparatus. The ideal situation is, of course, to provide a completely fluid-tight seal, and the sealing means of the present invention is provided in an effort to approach this ideal situation. If a slight amount of fluid leakage occurs, the apparatus will still function adequately but if the leakage becomes excessive it is apparent that it will interfere with the proper functioning of the apparatus. Accordingly, the expression effective fluid-tight seal as used herein is intended to encompass an arrangement which permits either no leakage or only a slight amount of leakage.

The dump valve apparatus of the present invention may be utilized at different depths and under different sea conditions or conditions of relative movement between the apparatus and the surrounding water. Accordingly, it is necessary to provide means for adjusting the amount of force required to open the dump valve apparatus so as to enable the valve to operate in the intended manner. In other words, the amount of force biasing the valve toward an open position is adjustable in the present invention such that the valve can be readily adjusted so as to open automatically under the conditions set forth above, and yet at the same time will remain firmly sealed in its closed position during normal operation of the apparatus.

An object of the present invention is to provide new and novel dump valve apparatus especially adapted for use in the pressure dumping line of underwater mining operations at great depths and under high pressures, and further where the normal operating pressure within the apparatus is greater than the ambient pressure.

Another object of the invention is the provision of new and novel dump valve apparatus which must remain closed and sealed at relatively small pressure differentials during normal operation of the apparatus.

Another object of the invention is to provide automatic dump valve apparatus which automatically opens to its discharge position upon change or interruption of liquid flow within the conduit means so as to cause solid particles dropping downwardly within the conduit means to be discharged out of the conduit means.

A further object of the invention is the provision of new and novel dump valve apparatus including means for adjusting the amount of force required to open the valve means.

A still further object of the invention is to provide dump valve apparatus which provides communication between the outside water surrounding the conduit means and the conduit means both above and below the valve means of the apparatus.

Still another object of the invention is to provide new and novel dump valve apparatus which is quite simple and inexpensive in construction, and yet which is quite efficient and reliable in use.

Other objects and many attendant advantages of the invention will become more apparent when considered in connection with the specification and accompanying drawings, wherein:

FIG. 1 is an elevational view of the automatic dump valve, apparatus of the present invention illustrating in phantom line the manner in which the apparatus may be connected in a conduit means;

FIG. 2 is a side view of the apparatus shown in FIG. 1;

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 1 looking in the direction of the arrows;

FIG. 4 is a sectional view taken substantially along line 44 of FIG. 2 looking in the direction of the arrows;

FIG. 5 is a longitudinal sectional view taken substantially along line 5-5 of FIG. 2 looking in the direction of the arrows;

FIG. 6 is a broken-away view illustrating a portion of the structure shown in FIG. 5, with the valve means moved into its open position as opposed to the closed position shown in FIG. 5;

FIG. 7 is a side view similar to FIG. 2 with certain of the components broken away and in exploded position to illustrate the assembly of the apparatus; and

FIG. 8 is a sectional view taken substantially along line 38 of FIG. 6 illustrating the manner of attachment of the sealing means of the present invention.

Referring now to the drawings wherein like reference characters designate corresponding parts throughout the several views, a body means or conduit means 10 includes a substantially cylindrical wall portion 12 through which is formed a central passageway 13 extending longitudinally of the elongated conduit means. This conduit means will be ordinarily disposed in a generally vertically extending position when in its operative relationship, the lower portion of the body means having an annular attaching flange 14 rigidly secured thereto, attaching flange 14 having a plurality of holes 15 disposed at spaced points therearound through which extend cap screws 16 for securing the attaching flange to a cooperating attaching flange of an adjacent section of pipe. A similar attaching flange 13 is secured to the upper portion of the body means, fiange 18 having a plurality of spaced openings 19 formed therein through which extend the cap screws 2t) for securing the upper fiange to a similar flange connected to an adjacent pipe section. It is apparent that the

cap screws

16 and 20 are utilized for securing the apparatus of the present invention in operative position within a conduit means. 7

Wall portion 12 of the body means is provided with a lateral opening 25 formed therein, this lateral opening providing communication between the passageway formed through the body means and the exterior of the body means. Opening 35 is of elongated configuration as seen for example in FIG. ,7, the opening extending in the longitudinal direction of the elongated body means and being widest at its lower portion 27 and tapering to a smaller width at the upper portion 28 thereof. Portion 27 of the opening which is the widest portion thereof extends through an arc of approximately of the wall portion 12 are cut away in such a manner as to taper to a point as seen in cross section in FIG. 3, for example, such tapered wall portions being indicated by reference numeral 25', these tapered wall portions affording clearance for the valve means hereinafter described so that it can swing from its closed position to its. open position. A first sealing portion indicated generally by reference numeral 30 is fixedly secured to the outer surface of the body means and extends inwardly of the edge portions of the wall portion defining opening 25 so as to effectively seal against the outer surface of the valve means hereinafter described.

Sealing means 34 includes a first elongated strip of sealing material 32 which may be formed of a suitable soft substance such as rubber or the like, this strip of material extending about approximately /2, of the opening 25 and extending about the upper portion thereof and extending down along the side portions of the opening to a point 33 as indicated for example in FIGS. 1 and 7. It is apparent that strip 32 will serve as a sealing gasket in combination with the valve means, this gasket being retained in operative position by an elongated gasket retainer member 37 formed of a suitable rigid material such as steel or the like, the retainer 37 being held in operative position by means of screws 37 which extend through suitable openings provided in

members Portions

32 and 37 and into a cooperating threaded opening provided in the wall portion 12. It is apparent that when the retainer member 37 is bolted into position as shown, member 37 will serve to clamp the resilient sealing gasket member 32 in operative position.

Members

32 and 37 are cut away as indicated at 35 to form a notch for receiving a bracket member hereinafter described.

A pair of

similar support brackets

42 and 43 which may be of substantially triangular configuration are secured to diametrically opposite points of the outer surface of the body means 10. Each of these

bracket members

42 and 43 is held in operative position by a plurality of screws 44 and 45 respectively which extend through suitable openings provided in the bracket members into cooperating openings formed in the wall portion 12 of the body means. It will be noted that these bracket members extend through the notched portions of

members

32 and 37 as mentioned previously and as indicated by reference numerals 35, these notched portions serving to provide clearance for the bracket members.

The valve means of the present invention is indicated generally by reference numeral 50, and as seen particularly in FIG. 7, it is shaped substantially complementary to the opening 25 formed in the body means so as to fit within the opening in the body means and having a slight clearance with the edges of the wall portion of the body means which define opening 25. It will be understood that when the valve means 50 is in its closed position as shown for example in FIGS. 1, 2 and 5, the inner surface of the valve means along with the inner surface of the wall portion 12 will define a substantially smooth cylindrical inner surface to the passageway formed through the body means.

The only interruptions to this substantially smooth inner surface occur at those portions which have been cut away so as to provide a sharp tapered edge such as the portions 25 mentioned previously, as well as the upper edge portion 56 of the valve means as seen in FIGS. 5 and 6.

A pair of

arms

52 and 54 each have one end thereof rigidly secured to the valve means 50 and extending laterally therefrom, arm 54- in turn joining with a portion 55 which as seen for example in FIGS. 1 and 3 extends a substantial distance in a 'direction substantially normal to the axis of

arm portions

52 and 54 so as to actually extend on the opposite side of the body means as seen in FIG. 1. Arm portion 52 extends through a suitable opening provided in bracket member 42 and is held in place by means of a flat washer 57 and a cotter pin 58. In a similar manner, arm portion 54 extends through a suitable opening provided in bracket member 43 and is held in place by a fiat washer 59 and a cotter pin 69. A counterweight member 62 as seen particularly in FIG. 4 is provided with a bore 64 formed therethrough which slidably receives the arm portion 55 whereby the position of the weight member may be adjusted along the length of arm portion 55. A threaded Wing nut 65 is threaded into an opening 66 extending normally from the bore 64 provided in the weight member, whereby the weight member may be locked in position at any desired location along arm portion 55, the weight member tending to pivot the valve means into its open position as seen in FIG. 6.

While the weight means is illustrated as being adjustably mounted on the associated arm means, it should be understood that when the valve is operating under known conditions, the weight means is fixed to the associated arm means and is not adjustable with respect thereto.

The valve means is shown in its normally closed position in FIGS. 1, 2 and 5, wherein it is sealed with respect to the body means, the pressure of the liquid stream within the body means and passing through the central passageway therein maintaining the valve means in its closed position. Upon interruption of the liquid stream within the body means, the ambient pressure and the weight means tend to pivot the valve means into its open position as seen in FIG. 6. It will be noted that the valve means is pivotally supported at an intermediate point thereof which is adjacent the lower end thereof and is spaced upwardly from the lower edge thereof approximately the over-all height of the valve means. When the valve means is in its open position as seen in FIG. 6, it will be noted that the surrounding water may pass beneath the valve means and into the lower portion of the body means.

When the valve meansis in its open position, it forms an angle with the inner substantially vertically extending surface of the wall portion 12 which is indicated by the letter a in FIG. 6, and which is preferably between approximately 45 and 60".

A sealing means or second sealing portion 70 is secured to the lower portion of valve means 50, and simi larly to the first described sealing portion 30, extends beyond the edge of the lower portion of the valve means so as to seal up against the adjacent portion of the cooperating member which in this case is the body means.

As seen particularly in FIG. 7, it will be noted that sealing portion 70 extends along the lower edge of the body means and up along the lower side edge portions thereof so that in its closed position as seen for example in FIGS. 1 and 2, the sealing portion 70 serves to seal the remaining portion of the lateral opening in the body means which is not sealed by the first sealing portion 30. The ends of the two sealing portions 30 and 70- fit snugly up against one another so as to provide an etfective fluidtight seal throughout the entire periphery of the opening within which the valve means is received. This sealing means is important since a small clearance is provided completely around the valve means.

Sealing portion 70 includes an inner sealing resilient gasket 72 formed of rubber or similar material, member 72 being in the form of an elongated strip and being held in place by means of a gasket retainer 74 formed of a rigid material such as steel or the like and which in turn is held in place by means of a plurality of screws 75 extending through suitable openings provided in

members

72 and 74 and being threaded into cooperating openings provided in the valve means 50.

It is apparent from the foregoing that there is provided new and novel dump valve apparatus which is especially adapted for use in the pressure pumping line of underwater mining operations at great depths and under high pressures, and further where the normal operating pressure within the apparatus is greater than the ambient pressure, and yet at the same time the pressure differentials acting on different sides of the valve means of the present invention are relatively small. With the relatively small pressure differential existing on the valve means, the valve means will be pivoted into its closed position as seen in FIG. 5 of the drawings, and held in such position as long as the operating pressure of the liquid within the body means is normal. When the pressure of the liquid within the body means drops below the normal level, the valve means may be adjusted by means of moving the weight means 62 along arm portion 55 so as to cause the valve means to automatically pivot into its open position as seen in FIG. 6, wherein the valve means will substantially fill the interior cross-sectional area of the body means such that particles of solid material falling downwardly within the liquid in the conduit means will be deflected by the valve means and pass outwardly of the body means as will be readily apparent. The amount of force required to open the valve means may be readily adjusted by adjusting the position of the counterweight means along arm portion 55. It is also apparent that when the valve means of the present invention is in its open position, communication is provided between the outside water surrounding the conduit means and the conduit means both above and below the valve means of the apparatus. The dump valve ap paratus of the present invention is also quite simple and inexpensive in construction, and yet is quite eificient and reliable in operation. As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, and since the scope of the invention is defined by the appended claims, all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are therefore intended to be embraced by those claims.

We claim:

1. Automatic dump valve apparatus for use in the pressure pumping line of underwater mining operations at great depths and wherein the normal operating pressure within said apparatus is greater than the ambient pressure, comprising an elongated body means having a passageway formed longitudinally therethrough, said body means having an opening formed therein providing communication between said passageway and the exterior of said body means, valve means pivotally supported by said body means and shaped substantially complementary to said opening in said body means so as to substantially close said opening when in closed position and having a slight clearance with respect to said opening, said valve means pivoting to an open position automatically under certain conditions of pressure on opposite sides thereof so as to cause material moving in one direction through the passageway in said body means to pass outwardly of said body means, and sealing means for providing a seal between said body means and said valve means and for preventing leakage through the clearance between said body means and said valve means, said sealing means being mounted outwardly of said body means and said valve means and providing a fluid-tight seal therebetween when said valve means is in its closed position, said sealing means including a first sealing portion fixedly secured to the outer portion of said body means, said sealing means also including a second sealing portion fixedly secured to the outer portion of said valve means, the sealing portions cooperating to provide an effective fluid-tight seal completely around said valve means when in its closed position.

2. Apparatus as defined in claim 1, wherein said first sealing means extends about the upper portion of said opening in the body means with the first sealing means extending inwardly of the edge portions of the opening so as to engage the valve means in its closed position, said first sealing means extending about approximately /3 of the edge portion of said opening, said second sealing portion extending about the lower edge portion of said valve means and extending outwardly thereof for engaging the outer surface of the body means when said valve means is in its closed position, said second sealing portion extending about approximately /3 of the edge portion of said opening when the valve means is in its closed position.

3. Automatic dump valve apparatus for use in the pressure pumping line of underwater mining operations at great depths and wherein the normal operating pressure within said apparatus is greater than the ambient pressure, comprising an elongated body means including a wall portion defining a central passageway extending longitudinally of said body means, said wall portion having a lateral opening formed therein and being elongated in the direction of the elongation of said body means, said body means being normally disposed in a vertical position to define an upper portion and a lower portion of said opening, valve means shaped substantially complementary to the opening in said body means and having a slight clearance with the edges of said opening, said valve means including a top portion and a bottom portion adapted to be disposed adjacent the top portion and lower portions respectively of the opening in said body means, said valve means being pivotally supported by said body means at a point intermediate of said valve means and nearer to said bottom portion thereof than the top portion thereof, said valve means being movable from a closed position wherein it substantially closes the opening in the wall portion of said body means to an open position wherein said opening is opened and Wherein material moving in one direction to the passageway of said body means is caused to pass outwardly of said body means, sealing means including first and second sealing portion, said first sealing portion being secured to the outer surface of said wall portion and extending around a major part of said opening in said wall portion and extending inwardly of said opening so as to engage the outer surface of said valve means when the valve means is in closed position, said second sealing portion being fixediy secured to the outer surface of said valve means and extending outwardly of the edge of said valve means so as to engage the outer surface of said wall portion when said valve means is in closed position, said first sealing portion extending about the upper portion of said opening while said second sealing portion extends about the lower portion of said opening when said valve means is in closed position, said valve means in its open position extending at an angle of between approximately 45 and 60 with respect to the substantially vertically extending inner surface of the adjacent wall portion, and adjustable means for adjusting the amount of pressure differential required to cause automatic opening of said valve means, said adjustable means including a laterally extending arm means operatively connected with said valve means, weight means movably supported on said arm means and means for selectively positioning said weight means along said arm means to obtain the desired adjustment, said adjustable means normally biasing said valve means toward its open position.

' 4. Apparauts as defined in claim 3, wherein certain parts of said wall portion and said valve means are provided with tapered edges to accommodate proper movement of said valve means between its open and closed positions.

5. Apparatus as defined in claim 3, wherein said valve means is pivotally supported at a point approximately positioned A of the distance between the lower and upper edge portions of the valve means. i

6. Apparatus as defined in claim 3, wherein said opening formed in said wall portion is tapered to a smaller dimension toward the upper end portion thereof, said opening extending at its widest portion'through an arc of approximately 7. Automatic dump valve apparatus for use in the pressure pumping line of underwater mining operations at great depths and wherein the normal operating pressure within said apparatus is greater than the ambient pressure, comprising an elongated body means having a passageway formed therein and extending longitudinally thereof, said body means having formed therein a lateral opening providing communication between a portion of said passageway and the exterior of said body means, valve means shaped substantially complementary to said opening formed in the body means and adapted to substantially fill said opening with a slight clearance with the edges of said opening when the valve means is in closed position, said opening in said valve means being elongated in a direction extending longitudinally of said body means, said valve means being pivotally supported by said body means at an intermediate point along said valve means, said valve means being automatically movable from a position closing said opening to a position opening said lateral opening and closing off the passageway through said body means under certain pressure conditions existing on opposite sides of said valve means so as to cause material moving in one direction through the passageway of said body means to pass outwardly of said body means, said body means and said valve means having sealing means supported on the outer portions thereof for providing an effective fluid-tight seal between said body means and substantially the complete periphery of said valve means when said valve means is in its posi tion closing the lateral opening in said body means, adjusting means comprising a laterally extending arm means operatively connected with said valve means and having weight means thereon to normally bias said valve means toward the position opening the opening through the side of said body means and closing off the passageway extending through said body means.

8. Apparatus as defined in claim 7 including means for selectively adjusting and fixing the position of said weight means relative to said arm means to thereby vary the amount of pressure differential required to operate said valve means.

1 0 References Cited by the Examiner UNITED STATES PATENTS 6/1900 Codd 137527.8 X 9/1925 Kangieser 137-521 X 3/1953 Jullien 137527.8 X 4/1957 Miller 137-5273 X 3/ 19 64 Atherton 251306 X FOREIGN PATENTS 3/1963 Great Britain.

WILLIAM F. ODEA, Primary Examiner.

D. J. ZOBKIW, Assistant Examiner.

Claims

1. AUTOMATIC DUMP VALVE APPARATUS FOR USE IN THE PRESSURE PUMPING LINE OF UNDERWATER MINING OPERATIONS AT GREAT DEPTHS AND WHEREIN THE NORMAL OPERATING PRESSURE WITHIN SAID APPARATUS IS GREATER THAN THE AMBIENT PRESSURE, COMPRISING AN ELONGATED BODY MEANS HAVING A PASSAGEWAY FORMED LONGITUDINALLY THERETHROUGH, SAID BODY MEANS HAVING AN OPENING FORMED THEREIN PROVIDING COMMUNICATION BETWEEN SAID PASSAGEWAY AND THE EXTERIOR OF SAID BODY MEANS, VALVE MEANS PIVOTALLY SUPPORTED BY SAID BODY MEANS AND SHAPED SUBSTANTIALLY COMPLEMENTARY TO SAID OPENING IN SAID BODY MEANS SO AS TO SUBSTANTIALLY CLOSE SAID OPENING WHEN IN CLOSED POSITION AND HAVING A SLIGHT CLEARANCE WITH RESPECT TO SAID OPENING, SAID VALVE MEANS PIVOTING TO AN OPEN POSITION AUTOMATICALLY UNDER CERTAIN CONDITIONS OF PRESSURE ON OPPOSITE SIDES THEREOF SO AS TO CAUSE MATERIAL MOVING IN ONE DIRECTION THROUGH THE PASSAGEWAY IN SAID BODY MEANS TO PASS OUTWARDLY OF SAID BODY MEANS, AND SEALING MEANS FOR PROVIDING A SEAL BETWEEN SAID BODY MEANS AND SAID VALVE MEANS AND FOR PREVENTING LEAKAGE THROUGH THE CLEARANCE BETWEEN SAID BODY MEANS AND SAID VALVE MEANS, SAID SEALING MEANS BEING MOUNTED OUTWARDLY OF SAID BODY MEANS AND SAID VALVE MEANS AND PROVIDING A FLUID-TIGHT SEAL THEREBETWEEN WHEN SAID VALVE MEANS IS IN ITS CLOSED POSITION, SAID SEALING MEANS INCLUDING A FIRST SEALING PORTION FIXEDLY SECURED TO THE OUTER PORTION OF SAID BODY MEANS, SAID SEALING MEANS ALSO INCLUDING A SECOND SEALING PORTION FIXEDLY SECURED TO THE OUTER PORTION OF SAID VALVE MEANS, THE SEALING PORTION COOPERATING TO PROVIDE AN EFFECTIVE FLUID-TIGHT SEAL COMPLETELY AROUND SAID VALVE MEANS WHEN IN ITS CLOSED POSITION.