US3029833A - Bottom loading emergency valve - Google Patents

Description

April 17, 1962 J. H. DE FREES 3,029,833

BOTTOM LOADING EMERGENCY VALVE Filed Dec. 29, 1958 4 Sheets-Sheet l INVENTOR.

JOSEPH h. DFS

A ril 17, 1962 J. H. DE FREES 3,029,833

BOTTOM LOADING EMERGENCY VALVE Filed. Dec. 29, 1958 4 Sheets-Sheet 2 INVENTOR. JOSEPH H- DE FEEES BY @1, W1 6% 404.

ATTORNEYS April 17, 1962 J. H. DE FREES 3,029,833

BOTTOM LOADING EMERGENCY VALVE Filed Dec. 29, 1958 4 Sheets-Sheet s INVENTOR. JOSEPH H. DE FEEES ATTORNEYS April 17, 1962 Filed Dec. 29, 1958 J. H. DE FREES BOTTOM LOADING EMERGENCY VALVE 4 Sheets-Sheet 4 INVEN TOR. JOSEPH H. DEFEEES BY @641, M1,, 50/043 Mm A TOENIE'YS 3,02,833 BOTTOM LOADING EMERGENCY VALVE Joseph H. De Frees, 414 Liberty St., Warren, Pa. Filed Dec. 29, 1958, Ser. No. 783,461 6 Claims. (Cl. 137-414) The invention relates to novel and improved liquid inlet and discharge control means particularly adapted for use in connection with containers for the storage or transportation of liquids of any kind, and particularly explosive or inflammable liquids such as gasoline or the like. The invention is more specifically applicable to the bottom loading of containers of the nature indicated.

In the loading of tanks containing gasoline, for example, the discharge of the liquid into the usual top manhole gives rise to splashing and turbulence, with consequent hazard from the development of explosive mixtures of air and hydrocarbon vapor. Much of this hazard is avoided by pumping the liquid, or otherwise causing it to flow, into the container through an opening in the bottom thereof. Several advantages of the bottom loading method are immediately apparent. The Operator can remain at ground level; the loading station can be more simply equipped, and several compartments may conveniently be loaded at one time.

Liquid storage or transportation tanks generally have a bottom discharge or outlet opening and a valve control therefor. If the outlet connections are damaged by accident or otherwise, discharge of the contents might result in a disastrous the with possible serious injury to the attendant, truck-driver, or others in the vicinity. Socalled emergency valve structures havetherefore been devised to prevent any discharge of the liquid except when the operator is in conscious control of the discharge operation. Such emergency valve is usually in a relatively inaccessible position, for example, immediately within the tank bottom, so as not to be susceptible to normal injury from collision or the like. In liquid flow communication with the emergency valve is a conventional operator-controlled valve, and both this valve and the emergency valve, being in series, must be opened to permit liquid discharge from the container.

It is of course feasible, in the case of a multi-cham bered tank, to carry the discharge passages from all the emergency valves to a common manifold at which point flow from each compartment may be controlled at a single operators control box.

It is an object of the present invention to provide a main control valve at the lowest point of the container, which valve incorporates, in novel and improved mannet, the functions of a loading and unloading valve while retaining the emergency safety features heretofore found only in the unloading valves'of the prior art.

It is a further object of the invention to provide emergency discharge valve means, which can likewise be utilized as a loading or inlet valve, and which can be used in multiple for the loading or unloading of a respective plurality of tank compartments simultaneously.

A further object of the invention is the provision of valve means of the nature defined in the last two preceding paragraphs, in combination with novel and improved float control means for automatically terminating the loading operation at a predetermined level in any or all of the containers.

A further object of the invention is to provide a load.- ing valve and float control means therefor wherein said float control means comprises primary and secondary 3,029,833 Patented Apr. 17, 1962 2 loading ducts, each with its own automatic float control, the secondary loading duct being adapted to permit entry of liquid at a lower rate than the primary duct, and to be automatically shut or? subsequent to the closure oi the primary duct to provide for a more accurate meas: urement of the contents.

A further object of the invention is to provide bottom loading means of the type' defined hereinabove, and adapted to achieve loading of one or more compartments at a relatively rapid rate, but without hazardous agitation of explosive or flammable liquid.

A further object of the invention is to provide novel and improved bottom loading valve means comprising a main loading or unloading valve of the emergency type, in combination with a primary and a secondary valve for loading purposes only, said primary and secondary valve each being controlled by its own respective float, and said primary valve being adapted to automatically control the time of closing of said main valve during loading of the container.

Other objects and advantages will be apparent from a study of the following specification, in conjunction with the accompanying drawings, in which: i

FIG. 1 is a schematic showing, in outline, of a valve system controlling liquid loading and unloading of main-compartment tank, wherein both the loading and unloading of each compartment takes place through a single main valve of the emergency shut-oil? type.

FIG. 2 is a top plan view, somewhat enlarged, taken on the line 22 ofFIG. l.

PEG. 3 is a vertical sectional view through a valve assembly, taken on the line 3-3 of FIG. 2, i

FIG. 4 is a view similar to FIG. 3, but showing certain parts in a different operating position.

FIG. '5 is a detail vertical sectional view of a float control for a valve. 7/

FIG. 6 is a fragmentary sectional view of a 801116 What modified embodiment of one operating element of the invention. T

It will be convenient for a general understanding of the operating system to first refer to FIG. 1 which shows schematically the more important operating elements. In this drawing reference character 20 indicates a conventional trailer tank having rolled end heads 21 and 22, and concave bulkheads 23 and 24 which divide the tank into three compartments A, B and C.

At the lowest point in each compartment is a combined inlet and discharge valve 25, the discharge feature there of being of the emergency controlled type. All threesuch valves are similarly constructed and operated. Inlet-outlet piping 26 connects each valve 25 with a manifold 27,

there being a simple manually controlled valve adjacent the point of communication of each pipe 26 with manifold 27. These valves are not shown, being conventional abut the valve plunger 37a, and'admit air from pipe 39.-

The significance of this arrangement will appear later.

This pipe 39 may be connected with a source of compressed air such as the air tank for the brakes.

A second air system, which is completely self-contained comprises the hand pump 42 connected by pipe 43 to air distribution manifold 44. Individual valve control wheels 45 admit air to pipes 46 which run to each emergency valve 25 so as to open the valve and permit discharge therethrough at the operators choice. As will appear, these emergency valves 25 can be opened only by purposeful admission of air thereto, and several remote controls are provided to vent the air chamber 42 to atmosphere under such conditions that the valves should not be opened. For example, when the tank trailer is in transit, closure of door 47 in the operators control box operates the plunger of valve 48 and vents pipes 49 and 50, said pipes being in continuous air-flow communication with air storage cylinder 46. The same effects can be achieved at a remote control point occupied by a frangible plug or valve 53 which is preferably located near the drivers cab. If the driver becomes aware of a dangerous condition he breaks plug 53 which immediately vents storage cylinder 42 and manifold 44. A similar emergency air control system is more fully shown and described in my prior US. Patent No. 2,600,977, granted June 17, 1952.

In each of the compartments, A, B, and C, I have provided a primary float 54 and a secondary float 55. As will appear, the primary float controls a valve which permits rapid loading of the compartment through enlarged inlet ports in the emergency valve assembly 25. As the liquid level nears the desired high point the primary valve causes closure of the enlarged orifices, but loading continues at a greatly reduced rate through much smaller openings, also in the emergency valve assembly 25. Accurate approach to the desired level is thereby assured, and the secondary valve ports are closed by secondary float 55 when said desired level is reached. The primary and secondary floats are in communication with their respective valves in the emergency valve housing through respective pipes 56 and 57. The floats are suspended near the compartment top in any suitable manner. In FIG. a float bracket 58 is shown attached to the annular wall 59 of the tank manhole by bolts 60.

Refer now to FIGS. 2, 3 and 4 for a more detailed description of the loading and unloading main valve which, as will appear, incorporates therein the primary and secondary float valves.

The tank bottom 63 has a drain pocket 64 in each compartment. In said drain pocket is a central aperture to permit an emergency valve to be seated therein. The emergency valve body 25 has an outturned connecting flange 25a for securement of the body in the drain pocket. The body 25 also has an inturned annular shoulder 25b to serve as a valve seat for valve disc 65 of the main valve which is a piston-type valve movable vertically in body 25. A lower portion 65 of the valve extends outwardly below the tank bottom and has an upper connecting flange 65a. Registered apertures in the drain pocket 64, and in flanges 25a and 65a, receives bolts 66 which seat in captive nuts 67 within the drain pocket and hold the complete assembly together.

Valve head 65 has a downward extension serving as an operating means, said means consisting of push rods 68 which are welded to the valve head at their upper end and their lower end to a disc 69. The disc 69 and valve piston 66 can be raised to unseat the facing ring 65 from its seat 25b by admitting air through pipe 46 into a pressure chamber 70 between a flexible diaphragm 71 and a rigid pressure cup 72 which is attached to flange 65a of the lower valve portion 65 by bolts 73. The air pressure has its source in the pressure pump 42 heretofore mentioned, and it is routed to the desired main valve by a selected control valve 45 in manifold 44. The air pressure is developed by a few manual strokes of an air pump in association with cylinder 42 whenever the operator is ready to discharge one of the compartments. Door 47 must of course be open, or cylinder 42 is vented through interference valve 48.

When the main valve is unseated as just described, the liquid contents discharge through openings 76, then between facing disc 65 and seat 25b, into discharge chamber 77 in the lower housing 65, and out through fitting 78 and pipe 26 to liquid manifold 27 (FIG. 1).

Attached to the upper end of housing 25 is a head portion 79 which can most conveniently be connected by a screw thread arrangement 80. A spring 81 is compressed between a shoulder on the head portion and an annular depression in the top of the main valve 66. This arrangement biases the main valve to closed position, and since the valve seat is completely within the tank compartrnent any physical impact or collision along the tank bottom only injures the valve-opening elements and accidental discharge of flammable contents is prevented.

The loading control will now be described, with reference particularly to FIGS. 2, 3, and 4. The main valve 66 has an aperture therethrough, centrally, the valve body being vertically slidable along a tube 84 fixed to end head 79. This tube permits passage of liquid upwardly through the main valve when and as permitted by primary and secondary valving devices controlled by the primary and secondary floats 54 and 55 heretofore mentioned in connection with the description of FIG. 1, and now to be more particularly described.

End head 79 is provided with a bonnet 35 attached to the end head by bolts 86. A flexible diaphragm 87 has its peripheral edge gripped between the head and the bonnet. The bonnet is centrally bored, the passage extending through an inwardly extending boss 88. Surrounding the boss is a spring 39 which has its lower end abutting a seat or plate 99 to normally maintain the diaphragm against an annular shoulder 91 at the top of the central bore 92 above sleeve 84.

Further structural details will be characterized during a description of one loading cycle.

Referring first to FIG. 1, and assuming that the operator desires to fill compartment A, he opens both doors 38 and 47. The opening of door 38 frees plunger 37a of valve 37, and permits air to flow through pipe 36 to top vents 34 as heretofore described, opening the vents. The operator now connects a pipe from his supply source (not shown) to liquid manifold 27 and opens the valve or valves from the manifold to the appropriate pipe 26 to compartment A.

Liquid under sufficient pump pressure to overcome any expected hydrostatic gravity head now flows through pipe 26 (FIGS. 3 and 4). As shown by the arrows the pressure raises valve 66 from its seat 25b, and the liquid can enter the compartment through the following channels.

(1) Channel 1 carries the greatest volume of liquid and enters the compartment through the free space past the main valve, laterally through openings 76 in valve housing 25 and upwardly through the drain pocket 64.

(2) Channel 2 includes the passage upwardly through tube 84, raising diaphragm 87 by compressing spring 89, and outwardly through a plurality of lateral ducts 95 after passing seat 91.

(3) Channel 3 includes scoop duct 96 into a peripheral chamber 97, and thence upwardly through duct 98 (FIG. 4) and tube 56 to the primary float valve outlet to be later described.

(4) Channel 4 includes scoop duct 99 (FIG. 3) into the upper chamber 100 above diaphragm 37, through boss 88, and through tube 57 to the secondary float valve outlet.

All four channels are open in the main valve position shown in FIG. 4.

When the liquid level approaches compartment-filled position the primary float valve (to be later more fully described), closes the outlet from tube 56 exerting a back pressure through tube 56 and duct 98 onto the top of main piston valve 66, producing an increasing tendency to close the main valve. Several factors contribute to this tendency, for example the effective area on the top of piston valve 66 against which the pressure is effective, and the compressive force of spring 81. Main valve 66 thereupon returns to its seat, shutting off channel 1. Channel 3 had already been shut off by the primary float valve.

Loading continues through channels 2 and 4 but at a greatly reduced rate. When the level rises to the point where secondary float 55 closes its escape outlet a back pressure develops in chamber 100 which, in cooperation with the pressure of compressed spring 89, closes the diaphragm valve against shoulder 91 cutting off channel 2. Channel 4 has been closed by float 55.

All loading channels are now closed. An indicator flow device announces this fact to the operator and he can close the appropriate manual valve at the manifold, and also make such other disconnections as are obvious.

Refer now to FIG. 5 for a specific description of a float valve control. It can be either the primary or secondary valve control since they are identical. The side wall 59 of the manhole collar supports a bracket 58 which has a pair of vertically spaced lugs 53a and 58b which are bored to slidably receive the hollow shaft 103 to which the floating element M4 is attached. It-is shown in full line position as idle or unsupported, and in broken line position as floating in valve closing position.

Tube 56, the lower end of which is shown in FIG. 4, connects with a cup 105 which is clamped to lug 58b in leak-proof arrangement. In idle position a foot M6 on the hollow shaft 103 rests on a spider 107 at an intermediate height in the cup 1195. Liquid rising through tube 56 passes into the cup chamber 165a and through perforate spider 107 into upper cup chamber M1151). Thence the liquid proceeds through aperture 108 in the hollow shaft wall, and upwardly to overflow the top of the shaft into compartment A.

As the liquid level rises, the float 104 rises, carrying the shaft and foot 195 with it. The foot has a resilient seat material on its upper surface which eventually contacts in sealing relationship an annular bead 109. Rising of the shaft has already brought slot 108 upwardly into the bore of lug 58b. Escape of liquid from the cup is therefore substantially prevented, developing the back pressure downwardly through tube 56 as heretofore noted. A weep hole 110 through foot 166 permits a minor amount of pressure bleeding so that the main valve can be subsequently opened without excessive eifort.

Briefly returning to FIG. 4 it may be noted that packing members 111 of the O ring type are used to seal the piston valve 66 externally and internally, and also the connection of the head 79 to housing 25.

FIG. 6 illustrates a somewhat modified embodiment of the invention in which a piston valve is substituted for the diaphragm S7 of FIGS. 3 and 4. Reference character 114 inticates the top of the main valve corresponding to member 25 in FIGS. 3 and 4. A bonnet 115 has a screw threaded connection with body 114, and has a hollow cylindrical interior provided with exhaust ports 116. A piston valve 117 is maintained on its seat 113 by spring 119. The spring is retained by cap 120. Liquid under pressure arises in central bore 84 and lifts the piston 117 against the bias of the spring. The piston is perforated by a central duct 121 which allows liquid under pressure to enter chamber 122 and thence through pipe 123 to a secondary float valve (not shown).

Flow also proceeds through a scoop duct 124 into a chamber 125 which has a pipe outlet (not shown) to a primary float valve also not shown but similar to the one already described with respect to FIGS. 3 and 4.

Operation is as follows. When the liquid level closes the primary float valve the back pressure. in chamber closes the main valve, flow thereafter proceeding only through ports 116 and duct 121, chamber 122 and pipe 123. When the rising liquid closes the secondary float valve the back pressure in chamber 122, in conjunction with spring 119, seats piston 117 and cuts off all loading flow.

In the embodiments described the loading flow through all channels can take place, for example, at over 1000 gallons per minute, but after closure of the main valve and its auxiliary channel the flow through the secondary inlets can be reduced to about 50 gallons per minute which makes for accuracy in loading.

What I claim is:

1. Liquid flow control means for an inlet port in a tank wall, said means comprising a cylindrical valve housing within said tank and having an inlet opening in its lower end in registry with said port, a main valve within said housing and spring biased towards closed position in said port, said housing having first, second, third and fourth outlet means through the wall of said housing, said main valve having an axial opening therein and a tube defining a passage extending from said axial opening and inwardly axially through said housing to establish an annular pressure chamber between said tube and said housing, said main valve being movable into said pressure chamber by liquid-entering pressure against the aforesaid spring bias, said main valve, when so moved inwardly, clearing said first outlet to permit liquid to enter said tank through said first outlet, liquid flow obstructing means extending across the inner end of said passage and defining therebehind a second pressure chamber within said housing, said flow obstructing means being spring biased towards tube-closing position but adapted to be moved to tubeopening position by liquid entering pressure and, when so moved to clear a path between said tube and said sec ond outlet, a first pipe in communication with said first pressure chamber and having a discharge end at an elevated level in said tank whereby to vent said first chamher, a second pipe in communication with said second pressure chamber and having a discharge end also at an elevated level in said tank whereby to vent said second pressure chamber, a first duct from said passage to said first chamber whereby to permit liquid to flow into said first chamber and thence through said pipe when unobstructed, a second duct from said passage to said second chamber whereby to permit liquid to flow into said second chamber and thence through said second pipe, when unobstructed, liquid level responsive means for closing said first pipe to thereby create a back pressure therein and in said first pressure chamber and to close said main valve, and liquid level responsive means for closing said second pipe to thereby create a back pressure therein and in said second pressure chamber and to close said flow obstructing means.

'2. Liquid flow control means as defined in claim 1 wherein said flow obstructing means consists of a flexible diaphragm spring biased to close the inner end of said passage.

3. Liquid flow control means as defined in claim 1 wherein each said liquid level responsive means consists of a float having a portion operatively contactable with the end of its respective pipe to close the same responsive to liquid rise to a predetermined level.

4. Liquid flow control means as defined in claim 1 wherein said main valve has a piston portion upwardly extending into said annular pressure chamber, and carrying pressure sealing means in contact with the respective concentric walls of said pressure chamber.

5. Liquid flow control means as defined in claim wherein the upper ends of said pipes are at respectively different levels.

6. Liquid flow control means as defined in claim 5 wherein the upper end of the first pipe in flow communication with said first pressure chamber is at a lowerlevel References Cited in the file of this patent UNITED STATES PATENTS Shipley Jan. 29, 1924 8 Davies Nov. 7, 1950 De Frees June 17, 1952 Sweeney Nov. 25, 1952 Rittenhouse May 18, 1954 Fraser Sept. 11, 1956 Oliveau et a1. Aug. 26, 1958 Tye May 5, 1959

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