1. Field of the Invention
The invention relates to a theft abating combination stud and nut assembly for affixation in openings around flanges on fluid flow conduits, such as oil field well head Christmas trees, refinery conduits, gas production pipe lines, and the like.
2. Brief Description of the Prior Art
Oil well Christmas trees are quite common on inland as well as offshore oil and gas wells. These assemblies are securely mounted at the top of the well and provide a number of valves and similar components to permit safe but controlled release of produced hydrocarbon constituents within the well and may be manipulated to close off such production and other fluids for safety or other purposes.
In some remote locations throughout the world, the Christmas trees on the wells are targets for thieves, who would cannibalize the Christmas trees and sell the valves and other parts on the black market. Typically, since the valving components making up the Christmas tree are secured one to another through housings or conduits having metallic outwardly extending flange members, such flange members are typically secured one to another using a series of threaded nut and bolt assemblies. There is a slight gap between the flange members, even when they are tightly secured one to another, because of a seal face around the interior of the flange, which actually seals the flanged members together, to avoid escape of producing fluids, or the like.
As will be appreciated, all that a potential thief need do to remove the flanges B, C one from another, is to place a similar wrench over each of the nuts F and apply an opposing torque to remove the nuts F from the studs E and separate the flange members, thereafter removing whatever valve component is desired to be stolen. The result of this action is not only the loss of the valve component, but the resultant loss of the integrity of the Christmas tree to control the well, as well as the loss of production from the well and, in turn, possible contamination of the surrounding areas with oil and/or gas, and possible pollution of rivers, streams and other waters nearby.
The above-described problem is equally applicable to fluid flow conduits other than Christmas trees, such as refinery conduits, oil and gas production conduits and pipelines, and any other fluid flow conduit where members are joined together with flange components affixed to one another by conventional nuts and studs.
The present invention addresses the problems associated with conventional prior art assemblies by providing a combination nut and bolt theft abatement system.
The present invention is directed to a theft abating combination stud and nut assembly for affixation in openings around first and second flanges of joining members of a fluid flow conduit assembly. The fluid flow conduit assembly may include an oil field Christmas tree, comprised of valves, meters and controls of various sorts, hydrocarbon pipelines, flange assemblies on numerous fluid flow conduits found in refineries and other fluid flow conduit assemblies incorporating flange members which are secured one to another by the use of a plurality of studs and bolts and where it is desirable for safety and or security reasons to assure the securement of the flanges against efforts by thieves or the like to disengage and remove the studs and nuts to disengage the flanges, for whatever may be the objective of the thief, or other unauthorized person.
A combination stud and nut assembly comprises an elongated stud member, including an external circumferentially defined threading system thereon, and further including first and second ends thereof. The stud member is made of a metal, plastic or other solid component which permits the stud to be placeable into tension during affixation. An outer central section length of the threaded stud member is hardened, preferably to at least from between about 55 and about 65 Rockwell C hardness, with at least a part the central section length being placeable between the first and second flanges upon affixation of the assembly onto the flanges.
The combination stud and nut assembly further comprises first and second nut members, each having an internal threaded system for companion inter engagement with the threading system along the stud member as the nut members are secured onto the stud member. The nut members each include first and second ends thereon and further include a smooth conically tapered outer surface extending from the first end to the second end.
In a preferred embodiment, at least one tensioning cavity may be defined on the outer surface of each of the nut members for insertion of an adjusting pin, or the like, for tightening of the nut members onto the stud member as the stud member is placed in tension during the affixation. The tightening of the nut member through use of the adjusting pin is accomplished by placing the stud in tension to slightly elongate the stud within the elastic limits of its composition so that the nut may be moved toward engagement position on the flange member without application of torque to either the stud or nut members. Of course, the invention need not include such alternative preferred embodiment. It is only preferable to provide any means for moving the nut toward the flange as tension is applied to the stud. For further example, epoxy or other similar hex or similarly designed flats could be cast or otherwise secured onto the exterior of the conical nuts, and a wrench applied upon them to move the nut toward the flange during installation. Thereafter, the flats could be broken off or otherwise removed from the exterior of the nuts.
Alternatively, the flats could be left in place after installation and, if thievery is not undertaken thereafter and the flats removed during theft, the flats could be used to remove the nuts if the flanges are to be disengaged from one another by a legitimate engineer or other authorized personnel.
Alternatively, the invention could be designed such that no such means are needed and the nut is permitted, for example, to simply gravitate toward the flange during the securement process, as tension is applied to the stud to elongate the stud within the elastic limits of its composition.
In another preferred embodiment, the stud and nut combination assembly provides for a series of slots defined on the inner face of said flanges, with the slots on the inner face of one of the flanges being vertically alienable with each of the slots on the inner face of the other of the flanges. Metallic bridge means are then insertable within the slots and disposed at least partially across the diameter of the lugs extending between the flanges, to resist sawing or hacking of a length of the stud at a point in between the flanges.
In yet another preferred embodiment, the flanges provide inner and outer faces and the assembly further comprises a circumferentially extending groove way defined on each of said inner faces of said flanges and outboard of the openings in said flanges. A metallic bridge means is houseable in the groove way for resisting cutting or hacking of the studs during attempted theft.
The present invention is also directed to a method for theft abatement of flanges joining members of a fluid flow conduit. A combination stud and nut assembly, as described herein, is provided. The flange members are oriented to align the openings with one another. A stud member is introduced into one of the flange openings. Each of the first and second nut members are sequentially threadingly engaged onto the respective ends of the stud member. Tension is then applied through the stud member to increase the length of the stud member sufficient to elongate the stud within the elastic limits of its composition. The control rod is introduced into at least one of the cavities on at least one of the nuts to manipulate said at least one of the nuts further toward the flanges to secure the nuts to the stud member and upon the flanges in at least hand-tight relationship. Tension is then released through the stud so that the stud thread members and the nut members become lockingly inter engaged and the stud member is in a secured position relative to the flange members. The steps are repeated, as required, in sequential incremental steps around the remaining openings of the flange members.
Now, with first reference to
As further detailed in
Also, as illustrated in
Now referring to
The combination stud and nut assembly 100 further comprises first and second nuts 20A and 20B. Each of the nuts 20A and 20B has an internal threading system 20C (
Each of the nuts 20A, and 20B have first and second ends thereof, 21 and 22, respectively. One of the ends, preferably the upper end 21, has a diameter which is smaller than the larger diameter for the other of the ends, such as the lower end, 22, such that the respective nuts 20A and 20B are provided in a smooth conically tapered outer surface 50 extending from the respective ends 21 and 22. The taper 50 provides a smooth outer surface of the respective nuts 20A and 20B, which do not have a plurality of faces thereon, such as the hexagonal or octagonal faces G of the conventional nuts F shown in
In a preferred embodiment the nuts 20A, 20B also include at least one torquing cavity 23 defined on the outer surface of each of the nut members 20A, 20B for insertion of an adjusting pin 40 for tightening of said nut members onto the stud members 20A and 20B as the stud members are placed into tension during affixation. It will be appreciated that, upon completion of the affixation of the nuts 20A, 20B onto the studs, the stud will remain somewhat in tension, even though the interengaging threads between the nuts and the studs are in engaged position. Such tensioning of the stud in securement relative to the nuts will further resist application of torque to the nuts and/or the stud to disengage same.
An additional preferred embodiment is shown in
Now, with reference to
When it is desired to use the combination stud and nut assembly of the present invention for theft abatement purposes, the conventional nuts F are removed by application of a torque wrench to the respective studs E around the flanges B and C. They are then replaced using the stud 10 of the present invention, with a central section 10C being aligned between the upper and lower internal faces of the flanges B and C. A nut 20A is hand rotated onto the upper end 10A of the stud 10 until its lower face comes into contact with the upper face of the respective flange member B, C. The steps are repeated with the other of the nuts 20B on the other of the flanges B and C. Thereafter, the nut 10 is placed into tension.
There are a number of conventional tensioning devices TD well known to those skilled in the art which may be utilized by providing a sleeve for the tensioner (not shown) which has internal threads which are companionly inter-engageable with the threads 10C of the stud 10. The sleeve would be placed over the stud 10 with an open end of the sleeve being placed on the upper face of the respective flange B, or C and hydraulically activated to apply tension to the stud 10 to elongate the stud within the elastic limits of its composition. While the stud 10 is placed in tension, a control rod is placed into one of the cavities 23 so that the stud 20A, 20B may be manipulated by hand so that it is hand-tight onto the upper surface of the respective flange B or C. When in tension, the respective threads of the slug will still be slightly engaged with the internal companion threads of the nut 20A, 20B, even though the stud 10 has been placed in tension and thus elongated. Tension applied to the stud 10 may now be released , but the stud 10 remains in tension due to the continued and further inter-engagement of the threads of the slug and those of the nut, and the tensioned stud and nut combination 100 are tightly secured against the respective flanges B and C.
It will be appreciated that the length of the stud 10 used to replace the conventional prior art stud E may be somewhat longer than the stud E, in order to provide for acceptance of a sleeve or other component of the tensioning device TD (see
While the foregoing is directed to the preferred embodiment of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims which follow.