GB2220716A

GB2220716A - An indicator system for threaded pipe coupling

Info

Publication number: GB2220716A
Application number: GB8814512A
Authority: GB
Inventors: Norman Brammer; Fred Albert Frape; David Peter; David Stewart Christie
Original assignee: Vetco Gray UK Ltd
Current assignee: Baker Hughes Energy Technology UK Ltd
Priority date: 1988-06-17
Filing date: 1988-06-17
Publication date: 1990-01-17
Anticipated expiration: 2008-06-17
Also published as: GB2220716B; GB8814512D0

Abstract

A connectible system 1 comprises a male part, which is threaded at a free end, a female socket or box part which is threaded at a free end 4 in the box, and complementary indicator means 6, 8 of the male 2 and female 3 parts which is adapted to indicate respective initial contact positions of each part and relative rotational positions thereof for engagement when the male 2 and female 3 parts are axially engaged to assemble the system 1. <IMAGE>

Description

AN INDICATOR SYSTEM The invention relates to an indicator system, particularly a stabbing and make-up indication system for threaded connections.

In making up the male and female elements of thread systems there is an optimum point of relative orientation where the male and female thread-starts are aligned such that they overlap and thus present the thread-starts in a position to permit engagement on initial rotation but also any axial forces allow a maximum circumferential engagement of the thread and do not cause tilting which may induce cross threading.

The possibility of thread jamming or crossing is increased in the case of fine threads, large diameter threads, remote thread make-up or where the components being made up are large, heaw or subject to external loads. One such case is large diameter tubulors used in oil and gas wells where joints of pipe up to 50 feet (1524 cm) long have to be made up on the rig floor often in adverse conditions and are subject to rig motions (offshore applications) wind forces and in some cases at inclined angles (slant well applications).

Various thread forms and alignment devices have been developed to improve alignment and thus improve thread make-up but no system to date has entirely eliminated the possibility of thread jamming or crossing.

Another factor related to preorientation of thread-starts is that of speed of make-up. By preorientation a part turn of one member to the other is eliminated. This also may be significant where the means of make-up is limited to a series of increments of rotation, by rig tongs for example. This means that a connection designed to make-up in 221 turns really means 22 min. and almost 32 max. and a part turn connector, say 41 turn really means 4 min., 2 max.

It is an object of the invention to seek to mitigate these disadvantages .of the prior art.

According to the invention there is provided a system comprising a male part, a female part, and complementary indicator means of the male and female parts which is adapted to indicate respective initial contact positions of each part and relative rotational positions thereof for engagement when the male and female parts are axially engaged to assemble the system.

The male and female parts may be threaded parts.

The complementary indicator means may comprise a marking on the external circumferential surface of the male part and a marking on the external circumferential surface of the female part.

The marking on the male part may comprise a paint mark, suitably an arrow which is directed axially.

The marking on the female part may comprise a paint mark, suitably having two parts for indicating an initial contact orientation of the threads and a further relative orientation of the threads.

One part of the paint mark on the female part may be a 'V' for axial alignment with the arrow of the male part.

The male and female parts may comprise interengaging stabbing connector parts of a fossil fuel well pipestring.

The markings may be provided on the respective male and female parts by a method comprising stamping stencil locations using gauges, and subsequently painting the markings.

The male and female parts may be loose connectors, or full joints, though for preference stamping may preferably be carried out on loose connectors after completion of machining and prior to a finishing treatment such as phosphating. However, marking may be carried out on full joints at any location.

A threaded system embodying the invention is hereinafter described, by way of example, with reference to the accompanying drawings.

Fig. 1 is a view of a threaded system in the made up condition; Fig. 2 is a perspective view to a smaller scale than that of Fig.

1 of that system in the stabbing position; Fig. 3 is a perspective view of a further embodiment in a made up position; Figs. 4 and 4A show steps in a method of applying the markings on the pin and box respectively each Figure showing a diametral and transverse sectional view of the pin and box; and Figs. 5 and 5A show further steps in the method of applying the markings on the pin and box respectively.

Referring to the drawings in which like parts are indicated by like numerals, there is shown a connectible system 1 comprising a male part, which is threaded at a free end, a female socket or box part which is threaded at a free end 4 in the box, and complementary indicator means S of the male 2 and female 3 parts which is adapted to indicate respective initial contact positions of each part (Fig. 2) and relative rotational positions thereof (Figs. 1 and 3) for engagement when the male 2 and female 3 parts are axially engaged to assemble the system 1.

The complementary indicator means may comprise a painted marking in the form of an axially directed arrow 6 on a circumferential external surface of the male part 2 inboard of the thread 7, and a painted marking 8 on the female part 3 on a circumferential external surface thereof adjacent the free edge of the box 4.

The marking on the female part may comprise a 'V' with its apex axially aligned and another part 9 circumferentially spaced therefrom, the 'V' 8 and the another part 9 respectively indicating the stabbing and make-up positions of the male and female parts 2 and 3.

The paint markings, which may be applied in any suitable manner, for example by spray or brush, are thus indexed to the thread markings.

In use to assemble the system 1 by stabbing and turning, the male part 2 and female part 3 are offered up to one another in axial alignment if possible, but with the arrow 6 aligned with the 'V' 8. The parts 2 and 3 are then rotated so that the arrow 6 moves to the marking part 9 on the female part 3. when the threads are properly engaged and the parts 2 and 3 are in the properly made-up position (Fig. 1).

Fig. 3 illustrates an embodiment in which the thread form is such that more than one turn is required for complete make-up. In this case two axially aligned second markings 9 on the female part are required as shown.

In both embodiments, the 'V' 8 and part(s) 9 are linked by a paint marking 10.

In order to apply the paint markings to the parts, gauges 11 and 12 for the threads of the male and female parts are used, after removing protectors if any and ensuring that the threads are clean.

For the male part or pins, a pin gauge, say P/N A30095 is placed onto the male part and rotated until the gauge shoulders out between threads 7 and the load shoulder 13, Fig. 4. A stamp is positioned in a window in the gauge and the position is marked firmly. The gauge is removed and the procedure is repeated at 1800.

For the female part or box, a P/N A30096 gauge is placed onto the t female part and rotated until the gauge shoulders out between threads and load shoulder 14, Fig. 4A. A stamp is positioned in a window in the gauge and the position is marked firmly.

Any thread protectors are then replaced as necessary or required.

The paint markings are then applied to the male part 2 (pin) and female part 3 (box) respectively by lining up pin stencil 15 slot with stamped arrow location, Fig. 5. The stencil is held firmly in place and paint is applied either by spray or brush. For the female part, the box stencil 16. slot is lined up with stamped 'V' on box. The stencil is held firmly in place and the paint is applied by spray or brush.

Any thread protector is then replaced.

The box indicator may be painted prior to welding but the pin indicator must be painted after welding to the pipe. The apparatus thus comprises a box gauge, a pin guage, pin and box stencils, white paint of a suitable quality e.g. Hanjnerite, Meboprime DNS or the like, and a stressless stamp providing the letter 'V' of a suitable height.

Thus using the invention it is possible to mark both the male and female parts or members 2 and 3 during manufacture such that the optimum rotational position for initial thread engagement is indicated. Combined with this is a final position indicator confirming full make-up of the connection and the linking of the two marks to indicate the angle of rotation necessary for proper make-up.

A system embodying the invention has the following ad#antages:- 1. Prealignment of the thread-starts substantially eliminates thread jamming and crossing.

2. Prealignment of the thread -starts reduces the angle of rotation for make-up.

3. Circumferential marking of male and female parts permits indication of this optimum position.

4. Circumferential marking also permits a further indication of full make-up (other indications are normally axial alignment of a shoulder and torque build up).

5. The linking (visually) by marking automatically indicates to the user the angle of rotation necessary for correct make-up.

6. By appropriate design of the marking the three elements of make-up, thread engagement (stabbing), rotation and final make-up position are indicated thus illustrating automatically on each product the proper and most efficient means of operation.

7. A tool or gauge system for locating and marking the threadstart reference point and a system for referencing this and paint marking the male and female parts.

Claims

1. A system comprising a male part, a female part, and compelementary indicator means of the male and female parts which is adapted to indicate respective initial contact positions of each part and relative rotational positions thereof for engagement when the male and female parts are axially engaged to assemble the system.

2. A system according to Claim 1, the male and female parts being threaded parts.

3. A system according to Claim 1 or Claim 2, the complementary indicator means comprising a marking on the external circumferential surface of the male part and a marking on the external circumferential surface of the female part.

4. A system according to Claim 3, the marking on the male part comprising a paint marker, suitably an arrow which is directed axially.

5. A system according to Claim 4, the marker comprising an arrow directed axially of male part.

6. A system according to Claim 4 or Claim 5, the markings on the female part comprising a paint marker.

7. A system according to Claim 6, the marker having two parts for indicating an initial contact orientation of the threads and a further relative orientation of the threads.

8. A system according to Claim 7, one part of the paint mark on the female part comprising a "V" for axial alignment with the arrow of the male part.

9. A system according to any preceding Claim, the male and female parts comprising interengaging stabbing connector parts cf a fossil fuel well pipestring.

10. A system according to any preceding Claim, the indicator means being provided on the respective male and female parts by a method comprising stamping stencil locations using gauges, and subsequently painting the markers.

11. A system according to Claim 10, the male and female parts being loose connectors.

12. A system according to Claim 10, the male and female parts being full joints.

13. A system according to Claim 11, stamping being carried out on the loose connection after completion of machining and prior to a finishing treatment.

14. A system, substantially as hereinbefore described with reference to the accompanying drawings.