CA2674159C

CA2674159C - Coupling assembly with check valve actuator

Info

Publication number: CA2674159C
Application number: CA2674159A
Authority: CA
Inventors: Kelvin Angermeier; Cameron Carr
Original assignee: Individual
Current assignee: Individual
Priority date: 2009-07-31
Filing date: 2009-07-31
Publication date: 2013-04-09
Anticipated expiration: 2029-07-31
Also published as: CA2674159A1

Abstract

A coupling assembly comprises a storage tank outlet pipe incorporating a shut-off valve, a check valve downstream of the shut-off valve, and a first pipe fitting, plus a drain conduit having a second pipe fitting adapted for non-rotating liquid-tight engagement with the first pipe fitting. The second fitting incorporates probe means configured to open the check valve upon engagement of the first and second fittings. The probe means is fixed within the bore of the second fitting so as to allow fluid flow therethrough. Opening of the shut-off valve after engagement of the first and second fittings thus allows fluid flow from the tank into the drain conduit. When the first and second fittings are disconnected, the probe means disengages from the check valve, thus closing the check valve and preventing flow out of the storage tank if the shut-off valve has been left open.

Description

COUPLING ASSEMBLY WITH CHECK VALVE ACTUATOR
FIELD OF THE INVENTION

The present invention relates in general to couplings for fluid conduits such as pipes and hoses, and in particular to such coupling assemblies use for oil storage tanks.
BACKGROUND OF THE INVENTION

Crude oil produced from wells drilled into subsurface formations is commonly piped from the wells to collector tanks, each of which typically receives oil flows from multiple wells. When a collector tank is full or nearly so, it must be drained, and this is usually done by pumping the oil from the tank through a drain conduit into a tanker truck.
For this purpose, the typical collector tank has an outlet pipe projecting through a lower area of the tank wall, with an end fitting adapted for connection to a drain conduit in the form of a drain hose from the tanker truck. To expedite the tank-draining operation, the outlet pipe's end fitting is usually a female camlock fitting, to receive a male camlock fitting on the tanker truck's hose. Camlock fittings are well known in the art; see, for example, U.S. Patent No. 3,860,274.

The outlet pipe is fitted with a ball valve (or other suitable type of shut-off valve), which is normally closed and is actuated to its open position only after the hose from the tanker truck has been connected to the end fitting of the outlet pipe. After the oil has been pumped out of the collector tank into the tanker truck, the proper procedure is to close the ball valve and then disconnect the hose from the outlet pipe.

Unfortunately, there have been many incidents of workers disconnecting the tanker truck's drain hose from collector tank outlet pipe while the ball valve is still open.
If the collector tank is completely empty or nearly so when this happens, little harm is done because there will be little or no oil available to spill from the outlet pipe.
However, if the collector tank has not been completely drained when the hose is disconnected with the ball valve still open, a substantial amount of oil can spill from the outlet pipe before someone belatedly closes the ball valve.

Incidents of this type typically necessitate costly and inconvenient environmental clean-up operations. An even greater concern, however, is the risk to worker safety.
Oilfield collector tanks are commonly insulated and fitted with heaters to keep the oil at an elevated temperature, in order to reduce the oil's viscosity and enhance its flowability.
There have unfortunately been numerous cases of workers receiving second-degree or even third-degree burns from hot oil gushing from a collector tank outlet pipe as a result of premature disconnection of a drain hose from the outlet pipe.

For the foregoing reasons, there is a need for an improved apparatus and method for draining oil from an oil storage tanks whereby the above-discussed problems are prevented. The present invention is directed to this need.

BRIEF SUMMARY OF THE INVENTION

In accordance with the general principles of the present invention, a check valve is provided in the outlet pipe of a storage tank (such as but not limited to an oilfield collector tank), and a hose (such as but not limited to a hose from a tanker truck) connectable to the outlet pipe for purposes of draining liquid from the storage tank is fitted with probe means adapted and configured such that the probe means will engage and open the check valve when the hose is connected to the outlet pipe. A
closed shut-off valve (typically a ball valve) between the check valve and the storage tank will prevent flow through the outlet pipe while the hose is being connected to the outlet pipe. The hose-to-pipe connection is made using a camlock fitting, or another suitable type of fitting that does not require relative rotation between its component parts.
When the hose is subsequently disconnected from the outlet pipe, the probe means will necessarily disengage from the check valve, which will thus automatically close.
Accordingly, it will be impossible for liquid to flow out of the storage tank through the outlet pipe upon disconnection of the hose, even if the shut-off valve in the outlet pipe has been inadvertently left in the open position.

In a preferred embodiment of the invention, the probe means comprises a pair of elongate metal probe members fixed to the internal bore of a male camlock fitting on the hose, with the probe members generally parallel to the axis of the fitting and disposed fully within the internal diameter of the fitting. The check valve is preferably a Duo-Chek valve, as manufactured by Crane Co., or a similar valve which like the Duo-Chek comprises a pair of semi-circular plates which are rotatable about a common diametrical axis, with biasing means (typically comprising a spring) to bias the plates toward the closed position, with the circumferential edges of the semi-circular plates in sealing engagement with the bore of the check valve body. The probe members are spaced and arranged such that when the hose is being coupled to the outlet pipe, they will push against the downstream sides of the semi-circular plates of the check valve, forcing them to the open position in which fluid can flow from the upstream side of the check valve through the check valve.

In alternative embodiments, the probe means may comprise only one probe member, which will act against only one of the semi-circular plates of the check valve.
This single-probe embodiment may also be used in conjunction with other types of check valves such as a butterfly-type check valve having a single, spring-biased circular plate which swivels about a diametrical axis.

In one aspect, therefore, the present invention provides an assembly including probe means fixed to the end of a hose element, plus a check valve installed in a pipe (such as the outlet pipe of an oil storage tank), with the hose and pipe being adapted for liquid-tight sealing using a non-rotating type of coupling such as a camlock coupling.

In another aspect, the present invention provides a male camlock fitting incorporating probe means generally as described above. In another aspect, the invention provides a tubular adapter incorporating probe means as described, with a male fitting on one end for connection to an outlet pipe, and with a female fitting on the other end for connection to the end of a hose. This latter embodiment facilitates use of the present invention with existing hoses without needing to modify the hoses, even if they have end fittings that are not compatible with the fitting on the outlet pipe to which connection is desired to be made.

Although the fitting on the end of the hose will typically be a male fitting regardless of the coupler type, and the fitting on the outlet pipe will typically be a female fitting, persons skilled in the art will appreciate that the present invention can be readily adapted for use with the alternative fitting combinations (e.g., female fitting on the hose, with a male fitting on the outlet pipe).

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to the accompanying figures, in which numerical references denote like parts, and in which:
FIGURE 1 is an elevation of a liquid storage tank having an outlet pipe incorporating a shut-off valve plus a check valve downstream of the shut-off valve, with the outlet pipe being adapted for coupling with a hose incorporating probe means for actuating the check valve, in accordance with a first embodiment of the present invention.

FIGURE 2 is an isometric exploded view of the hose, probe means, and outlet pipe shown in Fig. 1 FIGURE 3 is a cross-section through the hose, probe means, and outlet pipe as in Fig. 1, with the hose disconnected from the outlet pipe, and with both the check valve and the shut-off valve in their closed positions.

FIGURE 4 is a cross-section through the hose, probe means, and outlet pipe as in Fig. 1, with the hose coupled to the outlet pipe, with the probe means having actuated the check valve to an open position, and with the shut-off valve still in its closed position.

FIGURE 5 is a cross-section as in Fig. 4 but with the shut-off valve having been actuated to its open position, thus allowing liquid flow through the outlet pipe into the hose.

FIGURE 6 is a cross-section generally as in Fig. 5 but with the hose having been uncoupled from the outlet pipe so as to disengage the probe means from the check valve, thereby closing the check valve and preventing liquid flow out of the outlet pipe despite the shut-off valve remaining in the open position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The various embodiments of the invention may be best understood with reference to the Figures, which illustrate a typical liquid storage tank T having an outlet pipe 40 projecting through a lower region of the tank wall TW. Outlet pipe 40 incorporates a shut-off valve 42 (shown for exemplary purposes as a ball valve) with an actuator handle 44. Downstream of shut-off valve 42, outlet pipe 40 also incorporates a check valve 60, which in preferred embodiments will be of a type comprising a pair of semi-circular plates 64 which are rotatable about a common diametrical axis 62, and which are biased toward a closed position (i.e., permitting no fluid flow). The outer end of outlet pipe 40 has a female pipe fitting 50 of a suitable type, which in preferred embodiments will be a female camlock fitting.

A hose 30, for use in draining liquid from tank T through outlet pipe 40, has a male pipe fitting 12 (which will be a male camlock fitting in preferred embodiments) for liquid-tight coupling with female fitting 50. Male fitting 12 incorporates probe means 10, which in the illustrated and preferred embodiments comprises a pair of rigid elongate probe members 16 fixed to the inner bore 12A of male fitting 12, while leaving a path for fluid flow past or around probe means 10. In the illustrated embodiments, probe members 16 are fixed to inner bore 12A of male fitting 12 by fixing one end of each probe member 16 to a cross-member 14 extending diametrically across inner bore 12A (such as, for example, by welding or a threaded connection). However, persons skilled in the art will appreciate that various alternative ways of fixing probe members 16 to inner bore 12A of male fitting 12 can be readily devised using known design and fabrication principles techniques without departing from the scope of the present invention, provided that there remains a path for fluid to flow past probe means 10 and through male fitting 12.

In the particular embodiment shown in FIGS. 3-6, male fitting 12 is provided with an adaptor section 18 to facilitate use with a hose 30 having an existing pipe fitting 20, which might or might not be of a type engageable with female fitting 50 on outlet pipe 40. Accordingly, a number of different styles of adaptor 18 could be provided to ensure that male fitting 12, incorporating probe means 10, can be used with different types of hose-end fittings. Even when a hose end already has an existing fitting 20 which is engageable with female fitting 50, it will typically be advantageous to use male fitting 12 and adaptor 18 to avoid the need for modifying existing fitting 20 to incorporate probe means 10.

In FIGS 3-6, male fitting 12 is shown as a male camlock fitting with circumferential groove 24. Accordingly, female fitting 50 is shown as a female camlock fitting with a pair of lever arms 52, each of which is rotatable about a corresponding pivot pin 51 as shown. Each lever arm 52 incorporates a cam element 53 adjacent to the corresponding pivot pin 51, for engagement within circumferential groove 24 of male camlock fitting 12. Similarly, existing male fitting 20 is shown as a male camlock fitting with circumferential groove 34, with adaptor 18 being incorporating a female camlock fitting with lever arms 22, each being rotatable about a corresponding pivot pin 21 and each having a cam element 23 for engagement within circumferential groove 34 of male adaptor 18. FIG. 2 shows lever arms 22 and 52 in their open positions, while show lever arms 22 and 52 in the closed positions.

The use and operation of the coupling assembly of the present invention can be readily understood with reference to FIGS. 3-6. Although these FIGS 3-6 illustrate the particular embodiment describe immediately above, the operative principles are fundamentally the same for other embodiments as well.

FIG. 3 illustrates the above-mentioned embodiment hose 30 with male camlock fitting 12 and probe means 10 in an initial position, ready for engagement with female camlock fitting 50 connected to outlet pipe 40 in conjunction with check valve 60 and shut-off valve 42. In FIG. 3, both check valve 60 and shut-off valve 42 are closed.

In FIG. 4, male camlock fitting 12 has been engaged with female camlock fitting 50, with lever arms 52 of female camlock fitting 50 having been rotated to their closed (i.e., locked) positions, with their cam elements 53 disposed within circumferential grooves 24 of male camlock fitting 12. The process of coupling male camlock fitting 12 with female camlock fitting 50 has necessarily urged probe members 16 against semi-circular plates 64 of check valve 60 and moved them to their open positions.
However, flow through outlet pipe 40 is still prevented, because shut-off valve 42 remains closed.

In FIG. 5, the configuration of the assembly is the same as in FIG. 4 except that shut-off valve 42 has been opened, allowing flow through shut-off valve 42, check valve 60, and into hose 30. This is the normal operative position for draining liquid from storage tank T.

FIG. 6 illustrates the situation where with the assembly configured as in FIG.
5, male fitting 12 has been uncoupled from female fitting 50 without first closing shut-off valve 42. The uncoupling of male fitting 12 from female fitting 50 has necessarily caused male fitting 12 has been uncoupled from female fitting 50 probe means 10 to disengage and withdraw from check valve 60, thereby causing check valve 60 to be returned to its closed position (due to the action of the check valve's biasing means).
Therefore, liquid flow through outlet pipe 40 is prevented even though shut-off valve 42 remains open.

In this patent document, any form of the word "comprise" is to be understood in its non-limiting sense to mean that any item following such word is included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article "a" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one such element. Any use of any form of the terms "connect", "engage", "couple", "attach", or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the subject elements, and may also include indirect interaction between the elements such as through secondary or intermediary structure.
Relational terms such as "parallel", "perpendicular", "coincident", "intersecting", and "equidistant"
are not intended to denote or require absolute mathematical or geometrical precision.
Accordingly, such terms are to be understood as denoting or requiring substantial precision only (e.g., "substantially parallel") unless the context clearly requires otherwise.

of any form of the terms "connect", "engage", "couple", "attach", or any other term describing an interaction between elements is not meant to limit the interaction to direct interaction between the subject elements, and may also include indirect interaction between the elements such as through secondary or intermediary structure.
Relational terms such as "parallel", "perpendicular", "coincident", "intersecting", and "equidistant"
are not intended to denote or require absolute mathematical or geometrical precision.
Accordingly, such terms are to be understood as denoting or requiring substantial precision only (e.g., "substantially parallel") unless the context clearly requires otherwise.

Claims

1. A coupling assembly comprising:

(a) an outlet pipe assembly comprising:

a.1 an outlet pipe in fluid communication with a liquid storage tank, for receiving a flow of liquid from the storage tank;

a.2 a shut-off valve for regulating flow through the outlet pipe;

a.2 a check valve positioned downstream of the shut-off valve, said check valve being biased toward a closed position; and a.3 a first pipe fitting downstream of the check valve; and (b) a drain conduit having a second pipe fitting adapted for substantially liquid-tight and releasably locking engagement with said first pipe fitting, said second pipe fitting having an internal bore and incorporating probe means fixed to the second pipe fitting within said internal bore;

wherein:
(c) the first and second pipe fittings are engageable without relative rotation therebetween;

(d) the probe means is adapted to engage and open the check valve concurrently with the engagement of said first and second pipe fittings;
and (e) the probe means is fixed to the second pipe fitting in a manner permitting liquid flow around the probe means and through the internal bore of the second pipe fitting.

2. The coupling assembly of Claim 1 wherein the first pipe coupling is a female camlock fitting and the second pipe coupling is a male camlock fitting.

3. The coupling assembly of Claim 1 wherein the first pipe coupling is a male camlock fitting and the second pipe coupling is a female camlock fitting.

4. The coupling assembly of Claim 1, 2, or 3 wherein:

(a) the check valve comprises a pair of semi-circular plates rotatable about a common diametrical axis, said semi-circular plates being biased toward a closed position preventing liquid flow through the check valve; and (b) the probe means comprises a pair of elongate rigid probe members projecting longitudinally from the second pipe fitting, said probe members being configured and positioned such that each probe member will engage one of the semi-circular plates of the check valve and move said one of the semi-circular plate to the open position, concurrently with engagement of the first and second pipe fittings.

5. The coupling assembly of Claim 4 wherein the probe members are fixed to a cross-member spanning across and fixed at each end to the internal bore of the second pipe fitting.

6. The coupling assembly of Claim 1, 2, or 3 wherein:

(a) the check valve comprises a pair of semi-circular plates rotatable about a common diametrical axis, said semi-circular plates being biased toward a closed position preventing liquid flow through the check valve; and (b) the probe means comprises an elongate rigid probe member projecting longitudinally from the second pipe fitting, said probe member being configured and positioned such that it will engage one of the semi-circular plates of the check valve and move said one of the semi-circular plates to the open position, concurrently with engagement of the first and second pipe fittings.

7. The coupling assembly of Claim 6 wherein the probe member is fixed to a cross-member spanning across and fixed at each end to the internal bore of the second pipe fitting.

8. The coupling assembly of Claim 1, 2, or 3 wherein:

(a) the check valve comprises a single circular plate which swivels about a diametrical axis, said circular plates being biased toward a closed position preventing liquid flow through the check valve; and (b) the probe means comprises an elongate rigid probe member projecting longitudinally from the second pipe fitting, said probe member being configured and positioned such that it will engage one side of the circular plate of the check valve and move it to the open position, concurrently with engagement of the first and second pipe fittings.

9. The coupling assembly of Claim 8 wherein the probe member is fixed to a cross-member spanning across and fixed at each end to the internal bore of the second pipe fitting.

10. A pipe fitting having a coupling end an internal bore, said coupling end being adapted for substantially liquid-tight and releasably locking engagement with a mating second pipe fitting without relative rotation therebetween, wherein:

(a) the improvement comprises elongate rigid probe means fixed to the internal bore of the pipe fitting and projecting longitudinally beyond the pipe fitting; and (b) the probe means is fixed to the internal bore of the pipe fitting in a manner permitting liquid flow around the probe means and through the internal bore.

11. The pipe fitting of Claim 10 wherein the coupling end comprises a male camlock fitting.

12. The pipe fitting of Claim 10 wherein the coupling end comprises a female camlock fitting.

13. The pipe fitting of Claim 10 wherein the probe means comprises one or more elongate rigid probe members.

14. The pipe fitting of Claim 13 wherein the one or more probe members are fixed to a cross-member spanning across and fixed at each end to the internal bore of the pipe fitting.

15. A method of draining liquid from a liquid storage tank, said tank having an outlet pipe assembly incorporating a shut-off valve, said method comprising the steps of:

(a) installing a check valve in the outlet pipe assembly downstream of the shut-off valve, said check valve being biased toward the closed position;
(b) installing a first pipe fitting in the outlet pipe assembly downstream of the check valve;

(c) providing a drain conduit having a second pipe fitting adapted for substantially liquid-tight and releasably locking engagement with said first pipe fitting, said second pipe fitting having an internal bore and incorporating probe means fixed to the second pipe fitting within said internal bore, wherein:

c.1 the first and second pipe fittings are engageable without relative rotation therebetween;

c.2 the probe means is adapted to engage and open the check valve concurrently with the engagement of said first and second pipe fittings; and c.3 the probe means is fixed to the second pipe fitting in a manner permitting liquid flow around the probe means and through the internal bore of the second pipe fitting;

(d) with the shut-off valve in the closed position, engaging the first and second pipe fittings such that the probe means extends through the first pipe fitting so as to engage and open the check valve;

(e) opening the shut-off valve to permit liquid flow from the storage tank through the outlet pipe, shut-off valve, and check valve into the drain conduit; and (f) disengaging the first and second pipe fittings so as to withdraw the probe means from the first pipe fitting.

16. The method of Claim 15 wherein the first pipe coupling is a female camlock fitting and the second pipe coupling is a male camlock fitting.

17. The method of Claim 15 wherein the first pipe coupling is a male camlock fitting and the second pipe coupling is a female camlock fitting.

18. The method of Claim 15, 16, or 17 wherein:

(a) the check valve comprises a pair of semi-circular plates rotatable about a common diametrical axis, said semi-circular plates being biased toward a closed position preventing liquid flow through the check valve; and (b) the probe means comprises a pair of elongate rigid probe members projecting longitudinally from the second pipe fitting, said probe members being configured and positioned such that each probe member will engage one of the semi-circular plates of the check valve and move said one of the semi-circular plate to the open position, concurrently with engagement of the first and second pipe fittings.

19. The method of Claim 18 wherein the probe members are fixed to a cross-member spanning across and fixed at each end to the internal bore of the second pipe fitting.

20. The method of Claim 15, 16, or 17 wherein:

(a) the check valve comprises a pair of semi-circular plates rotatable about a common diametrical axis, said semi-circular plates being biased toward a closed position preventing liquid flow through the check valve; and (b) the probe means comprises an elongate rigid probe member projecting longitudinally from the second pipe fitting, said probe member being configured and positioned such that it will engage one of the semi-circular plates of the check valve and move said one of the semi-circular plates to the open position, concurrently with engagement of the first and second pipe fittings.

21. The method of Claim 20 wherein the probe member is fixed to a cross-member spanning across and fixed at each end to the internal bore of the second pipe fitting.

22. The method of Claim 15, 16, or 17 wherein:

(a) the check valve comprises a single circular plate which swivels about a diametrical axis, said circular plates being biased toward a closed position preventing liquid flow through the check valve; and (b) the probe means comprises an elongate rigid probe member projecting longitudinally from the second pipe fitting, said probe member being configured and positioned such that it will engage one side of the circular plate of the check valve and move it to the open position, concurrently with engagement of the first and second pipe fittings.

23. The method of Claim 22 wherein the probe member is fixed to a cross-member spanning across and fixed at each end to the internal bore of the second pipe fitting.