GB2133859A

GB2133859A - Flow control valve

Info

Publication number: GB2133859A
Application number: GB08328810A
Authority: GB
Inventors: Evan Philip March
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-01-21
Filing date: 1983-10-28
Publication date: 1984-08-01
Also published as: GB8328810D0; DE8334655U1; DE3343659A1; CA1214150A; GB2133859B

Abstract

A spring loaded, manually operated, flow and relief valve, to be associated with each chamber of a tanker or tank, preferably can be conveniently and permanently mounted as a discharge orifice in the captive cover, or manhole cover, of such tanker, and conveniently located particularly in the annular margin between the radial flange and a centrally located hingible disc closure of the manhole cover. Specifically, the valve mechanism comprises a disc plate 43 which is biassed by a spring 49 to close an orifice 22. The plate 43 is coupled by an arm 50 to a rotatable drive shaft 34. To open the valve, the shaft 34 and thus the plate 43 are depressed against the action of springs 36, 49 respectively and subsequently rotated. The plate 43 can move against the action of the spring 49 to relieve excess pressure in the orifice 22. <IMAGE>

Description

SPECIFICATION Unloading valve for an over-turned tank The invention relates to a fluid valve for emergency unloading liquid contents of an overturned tank.

This novel valve also finds application in other environments where a controlled flow discharge or access of the liquid is desired and the normal orifice of fluid discharge or access is either frozen closed, or for safety reasons, it is too risky to use it.

In North America caustic, inflammable, and other materials and liquids are constantly conveyed, to a great extent by lorry or truck tank carriers which comprise either a tractor, as the prime mover, which pulls a detachable passive trailer carrying thereon a liquid containing tank, or a tank with a plurality of chambers each containing various or similar liquids; or, a single chassis with or without a prime mover and carrying on the chassis, a liquid containing tank with a single or a plurality of liquid containing compartments or chambers. In one environmental application, the tank may be a railway tank car.

These tank trailers, or "tankers" as they are more colloquially called, generally are interpartitioned into chambers and at the top of each chamber there is an access hole to the outside by which the respective chamber is filled or possibly unloaded of its contents, but in which this upper access hole is large enough to accommodate the body of a person so that inside inspection of the tank chambers may be facilitated.

The access or fill hole is of various sizes often designated by regional law providing for minimum dimensions and usually embodies a man-access for repairing and cieaning and a fill section which may or may not be vented. The access hole is closed by a manhole cover that is, itself, a captive cover plate with a circumscribing retaining ring that mechanically secures the captive cover plate over the access hole. This is the standard method of covering and of sealing the access hole.

Generally, centred on the cover plate is a latch operated, disc closure, with or without vent means, which when the latch is manually released, swings away from the cover plate and moves with it, the disc closure so that access into the chamber is obtained through an aperture defined by the marginal annulus of the captive cover plate. In some configurations, the access hole is oval, but most generally is circular and the captive cover plate corresponds to the dimensions of the access hole and may be attached thereto by an outer ring, or internal tie-down bolts, or may be secured on or bolted flange-style as those skilled in the art will know.

If, perchance the tanker has overturned, as a result of a mishap on the highway, removal of the liquid in each chamber is presently achieved by a number of methods; (1) uprighting the tanker so that normal removal practices can take place; (2) open the latch to swing open the disc closure and dump the contents into an interim basin positioned adjacent to the access hole and then pump the liquid from the interim basin to a new storage tank; and, (3) drill a conveniently located hole through the chamber wall, tap the same, and insert a new stop and cock or other valve, and drain the contents.

Those skilled in the art will appreciate that each one of these alternatives is not always available, because of either the physical location of the overturned tanker, the volatility, or the caustic nature of the contents, or the nature of the surrounding neighbourhood where the mishap has taken place, or even because of the absence of suitable equipment to upright the tank and to unload its contents.

The invention, therefore, achieves a spring loaded, manually operated, flow and relief valve to be associated with each of such chambers of a tanker. Preferably, this flow valve can be conveniently and permanently mounted as an emergency discharge orifice in the captive cover, when conveniently located in the annular margin between the radial flange and hingeable disc closure and situated to unload the liquid to a level where safe opening of the access hole can be achieved to then enable an unloading hose to be inserted into the compartment to allow the removal of the balance of the liquid cargo.

Where two such valves are used with each chamber, one acts as the liquid drain route for the contents, the other as a spring loaded air relief valve for displacement of the liquid contents removed from the chamber with air from the environment, while not allowing liquid to leak through the same. The dual valve use is needed if the spring loaded relief valve normally located in the disc closure of the captive cover plate becomes inoperative.

The invention, therefore, contemplates a valve mechanism comprising: (a) a valve body, (i) carrying a valve controller, and, (ii) defining a first larger orifice; (b) a gate, mounted for movement relative to the valve body and positioned to sealingly close and to open the first larger orifice; and, (c) means urging the gate into sealing, closing relation with the larger orifice, but responsive to the valve controller for positioning the gate open.

The invention further contemplates a valve mechanism comprising: (a) a valve body, (i) defining a major and minor bore, (ii) carrying a valve controller that includes a shaft that extends and slidingly travels in sealing engagement through the minor bore: (b) a valve gate with a depending stem, mounted for movement relative to the valve body, the gate positioned to sealingly close and to open the major bore, the stem connected to the shaft and responsive to the relative position of the shaft and the valve body; and, (c) means biasing the gate into sealing and closing relationship relative to the larger orifice.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a perspective of the prior art method of removing contents from an overturned trailer using a basin and pump.

Figure 2 is the same perspective, but utilizing the valve of this invention, and hence eliminating the need and risk of a basin.

Figure 3 is a perspective of a typical captive cover plate, showing the preferred location of the novel valve of this invention, and in phantom, the preferred location of a second of such valves when two are desired.

Figure 4 is a plan view of the valve of figure 3.

Figure 5 is a cross-sectional view along lines V-Voffigure 3.

Figure 6 is an assembly view, partially in section, of the upper portions of the valve controller operating stem.

Figure 7 is a partial cross-sectional view of the position of the gate when the valve mechanism is used as a relief valve.

Referring to figure 1, an overturned tanker 10 is shown with a recovery tractor and tank 1 5 at the margins of a road. The contents of one chamber of the overturned tanker 10 has been organized to flow into a basin 11 , which, by gravity, flows down hose 12 to pump 13 for pumping conveyance into a corresponding chamber in the recovery vehicle 1 5. In this figure the captive cover plate 14 (or manhole cover) of the recovery vehicle 1 5 is shown lying on the highway so as to permit the loading of the liquids from the overturned tanker 10, although in general, the captive cover plate 14 need not be removed when it is fitted with a latchable operated disc closure 1 6 defined by the outer annulus of the cover plate 14 and which is a conventional structure in this art.

Figure 2 is a depiction of the similar incident or mishap, but using the valve of this invention.

Hence, the need for an overflow basin 11 is eliminated.

The valve of this invention is generally indicated as 20 in figures 3, 4 and 5 and comprises a body 21 that defines a major and a minor orifice 22 and 23. The major orifice 22 is fitted with an upstanding shoulder 24, having a hose coupling which in this embodiment is an exterior standard type thread 25, while as those skilled in the art will appreciate that the shoulder 24 could be profiled for any other hose coupling, e.g. cam and groove. A dust cover or cap 26, in this embodiment, threadingly engages the threads 25 in order to keep contaminants out of the major orifice 22 until emergency need arises.

Extending out of the minor orifice 23 is, as part of the valve controller, a sliding operating stem 31 which extends through an annular shoulder 26, the outside diameter of which is likewise threaded to a standard type thread 27 so that a protective controller cap 28 can be over threaded the operating stem 30 when not in use or possibly suitably protected with an 0 ring type dust cap.

The valve body 21 therefor is affixed by convenient means, either as by welding or bolting or riveting or the like, to the annular perimeter of the manhole cover (or captive cover plate 14) to another convenient location that allows communication with the interior of the tank chamber.

Inside the tank, the valve depends and has an end plate and operating guide 40 disposed and fixed at a predetermined distance from the valve body 21. This is achieved by the utilization of four bolts 41 and appropriate spacers 42 surrounding the bolts, each mounted symmetrically about the major orifice 22 as shown in the figures. A disc gate 43 is positioned at the underside of the orifice 22 and for sealing, an annulus of rubber, or elastomeric, or other appropriate material is used to form an annular seal 44. This seal 44 may be secured in a ring 43 by the milling of an annular recess 45 into which the sealing ring 44 may be securedly fixed.

The disc 43 has a centrally depending valve stem 47 whose distal end freely extends through an aperture 46 defined by the end plate and operating arm 40, and through another aperture 56 defined by the operating arm 50. There the distal end of the shaft 47 is held in juxtaposition with the obverse or exterior side of the operating arm 50 by a stop means in the form of a roll pin 48 that extends through the shaft; hence, the roll pin 48 is positioned on the exterior side of the operating arm to act there as a stop means for the operating arm. The purpose of operating arm 50 will be described more particularly hereinafter, but its home position, and referring to figure 5, is the phantom position, while the operating position is the bold position of the same figure. In figure 7, the home position of the operating arm 50 is shown bold.

A coil compression spring 49 is positioned between the underside of the disc 43 and the end plate 40 and, thereby provides a continuous biasing force against the disc gate 43, urging the same to sealingly close the major orifice 22.

In a very similar manner, the sliding operating stem 30 extends through the minor aperture 23 and a corresponding orifice in the end plate 40 and the operating arm 50. In a convenient manner, as by welding joint 53 the distal end of the operating stem 30 is secured to the movable operating arm 50. The operating stem 30 is conveniently made of three coaxial aligned and fitting parts, an upper shaft 31 extending into a lower shoulder region 33 defining a lower central recess 32 into which fits an operating shaft 34.

The upper shaft 31 profiles a hexagonal nut as an operating head 35. A second coaxial coiled spring 36 is positioned between the end plate 40 coaxial with the operating shaft 33 to urge against the underside of the shoulder 33 of the upper shaft 31. Conveniently, interspaced between the upper portion of the spring 49 is a roll pin 60 extending through the operating shaft 33 that acts as the bearing surface for the upper shaft 31. In order to provide a sealing arrangement between the slidable upper shaft 31 and the circumscribing collar 26 thereof an 0 ring 29 is mounted in a recess defined by the inner bore 23 to provide a sealing interface.

As will be seen in figure 5, when the operating stem 30 is pushed downward as by finger (as shown) or by other mechanism, from the home or phantom position downward to the operating, or bold position, in accordance with the vertical arrow 60, the operating arm 50 descends to the bold position shown and pushes against the roll pin 48 pulling the disc gate 43 open. Liquid flows, as shown by the flow arrows 70, out of the major orifice 22 into the hose 12 of figure 2 for convenient conveyance as required.

in order to avoid the need for holding the sliding operating stem 30 in the depressed position, a partial circumferential interlocking groove 75 is disposed in the internal diameter of the stem housing 26 and acts, as will be noted hereafter, as a locking groove. This groove extends, at one end, upward into a vertically communicating slot 76.

The sliding operating stem 30 is fitted a protuberance or pin 77, so that when it is depressed downward from the phantom to the bold position of figure 5, the protuberance slides down the vertical slot 76 and if then, the sliding operating stem 30 is rotated, as illustrated by arrow 80, the protuberance 77 enters the horizontally positioned circumferential internal locking groove 75 to constrain the operating stem 30 and hence the disc gate 43 in the open and bold position of figure 5. Hence, for this convenience, the upper head of the operating stem 30 is fitted'with the profile of a nut 35 so that this locking action may be conveniently achieved with use of a wrench.

Referring to figure 3 in phantom, is shown, the position of a second such valve 20', although it might be located anywhere in communication with the chamber. In operation, one of the valves 20 has its major orifice communicated and threaded onto the end of the hose 12 for removal of the liquid and the operating stem 30 is locked into the open position by rotating the same so that the protuberance 77 enters the horizontal slot 75 to constrain it. The second or phantom valve 20' is allowed to remain in the normal closed position, but the caps 26 and 28 of the major and minor orifices 22 and 23 thereof are removed.As the liquid flows out the major orifice 22, of the main valve 20, and referring to figure 7, the phantom valve 20' will allow air to flow past the disc gate 43 since the "vacuum" created in the tank will overcome the biasing and urging force of the coil spring 49 of that valve. This action is achieved because the valve stem 47 extends "freely" through the apertures 46 and 56. Thus any vacuum in the tank chamber, that provides a pressure differential across the gate 43 that is greater than the biasing force provided by the coil spring 49, allows the gate 43 to descend (the bold position of figure 5), while the operating arm 50 remains in its home position so that a steady stream of fluid will pass out the major orifice 22 of the valve 20. The flow of air passing through the major orifice 22 of the phantom valve 22' into the chamber inhibits liquid escaping out of the phantom valve 20'.

Those skilled in the art will now appreciate that the valves 20 could be located, conveniently, not on the manhole cover or the captive cover plate, but at any other conveniently located position.

Claims

1. A valve mechanism having: (a) a valve body, (i) carrying a valve controller, and, (ii) defining a first larger orifice; (b) a gate, mounted for movement relative to the valve body and positioned to sealingly close and to open the first larger orifice; and, (c) means urging the gate into sealing, closing relation with the larger orifice, but responsive to the valve controller for positioning the gate open.

2. The valve mechanism as claimed in claim 1, further characterized in that the valve controller is not in coaxial alignment with either the first larger orifice or gate.

3. The valve mechanism as claimed in claim 2, further characterized in that the valve controller is disposed a predetermined distance and exterior of the larger orifice, and in a plane coincident with the centre of the larger orifice and the centre of the gate.

4. The valve mechanism as claimed in claim 3, further characterized in that means (c) includes a coiled compression spring mounted coaxial to the centre of the larger orifice.

5. A valve mechanism having: (a) a valve body, (i) defining a major and minor bore, (ii) carrying a valve controller that includes a shaft that extends and slidingly travels in sealing engagement through the minor bore; (b) a valve gate with a depending stem, mounted for movement relative to the valve body, the gate positioned to sealingly close and to open the major bore, the stem connected to the shaft and responsive to the relative position of the shaft and the valve body; and, (c) means biasing the gate into sealing and closing relationship relative to the larger orifice.

6. A valve mechanism having: (a) a valve body, (i) defining a major and minor bore, (ii) carrying a valve controller that includes a shaft that extends and slidingly travels on sealing engagement through the minor bore, the shaft carrying an operating arm that moves with the shaft; (b) a valve gate with depending stem that extends through the operating arm and is movable in response to the positional location of the operating arm, so that the valve gate is positioned to sealingly close and to open the first and larger orifice; and, (c) means biasing the gate into sealingly closed relationship relative to the major bore but which may be overcome by the operational position of the operating arm thereby to open the major bore.

7. The valve as claimed in claim 6, further characterized in that the stem extends freely through the operating arm so that when there is a pressure differential across the gate greater than that of the biasing means, the gate opens.

8. The valve as claimed in claim 6, further characterized in that the stem extends freely through the operating arm and there is means for moving the stem in response to the location of the operating arm.

9. The valve as claimed in claim 6, 7 or 8, further characterized in that the biasing means is a coiled spring coaxial with the valve stem.

10. The valve as claimed in claim 5, 6 or 7 further characterized in that a second biasing means to bias the shaft to a home position that nominally closes the gate against the major bore.

11. The valve mechanism as claimed in claims 5, 6 or 7, further characterized in that the shaft and the valve stem are in a coincident plane.

12. The valve mechanism as claimed in claim 1, 2 or 3, further characterized in that the major bore defines a hose coupling means thereabout for mating the same to a hose or the like.

13. The valve mechanism as claimed in claim 8, 9 or 10, further characterized in that the major bore includes a hose coupling means thereabout for mating the same to a hose or the like.

14. A closed liquid containing chamber having walls, the walls defining at least one valve means as claimed in claim 1, 2 or 3.

1 5. A closed liquid containing chamber having walls, the walls defining at least one of the valve means as claimed in claim 4, 5 or 6.

1 6. A closed liquid containing chamber having walls defining at least two valve mechanisms as claimed in claim 6, 7 or 8.

17. A valve mechanism substantially as described with reference to figures 4 to 7 of the accompanying drawings.