Method and apparatus for forming groove in pipe element

Abstract

A method of forming a circumferential groove in a pipe element by cold working the pipe element using opposing rollers determines the diameter of the groove while the pipe element is rotating between the rollers. An apparatus for performing the method uses an instantaneous determination value of the slot diameter in a feedback loop to control operation of the apparatus and to stop slot formation when the slot diameter is within a specified tolerance.

Description

[0001] This application is a divisional application of application number 201910629333.3, application date July 18, 2014, and titled “Method and device for forming grooves in pipe elements”. Technical Field

[0002] The present invention relates to a method and a device for forming a circumferential groove in a pipe element. Background Art

[0003] Pipe elements include any pipe-like items, such as pipe blanks and fittings, including, for example, elbows, T-joints and straight pipes and components such as valves, strainers, end caps, pump inlets and outlets, etc., which can be sealed together in an end-to-end relationship by using a mechanical pipe coupling, one example of which is disclosed in U.S. Patent No. 7,086,131. The coupling is formed by two or more sections connected end to end by threaded fasteners. In use, the coupling sections are positioned to surround the pipe element and are close to each other and engaged with the pipe element by tightening the threaded fasteners. The pipe element may have a circumferential groove that is engaged by a radially protruding key strip on the pipe coupling so as to provide favorable constraints for the axial loads experienced by the pipe element when the pipe element is under internal pressure from the internal fluid. An elastic gasket, usually in the form of an annulus, is positioned between the coupling section and the pipe element to ensure the fluid tightness of the joint. The gasket may have a sealing gland that uses the internal fluid pressure in the pipe element to increase the maximum pressure to effectively prevent leakage. The gasket is radially compressed between the coupling segment and the pipe element to achieve the desired fluid-tight seal.

[0004] In order to form a liquid-tight joint by using a mechanical coupling with a grooved pipe element, it is necessary to control the size of the circumferential groove of the pipe element so that the groove is properly engaged with the key strip of the coupling element and also allows the segments to move toward each other and fully compress the gasket to achieve a liquid-tight seal. The groove can be formed by cold working the side arms of the pipe element between opposing rollers, which are forced to move toward each other when the opposing rollers rotate around substantially parallel rotation axes so as to displace the material of the pipe element (usually through hydraulic components). The pipe element rotates accordingly (or around the roller track of the pipe element) and forms a groove around the circumference of the pipe element. Since the pipe size is allowed to have tolerances, it is difficult to control the size of the groove. For example, for steel pipes, the tolerance on the diameter can be up to + / -1%, the wall thickness tolerance is -12.5% ​​without a fixed upper limit, and the out-of-roundness tolerance is + / -1%. These larger dimensional tolerances bring challenges when forming circumferential grooves by cold working. It would be advantageous to develop a method and apparatus to actively measure parameters such as groove diameter and use these measurements to control the motion of the groove forming rollers as they form the grooves. This would avoid the prior art trial grooves and measurement / adjustment procedures. Summary of the invention

[0005] The present invention relates to a method for forming a circumferential groove in a pipe element having a longitudinal axis. The method is implemented by using a driving roller and a grooving roller. In an exemplary embodiment, the method includes: engaging the pipe element with the drive roller; engaging a grooving roller with a pipe element; forming the grooves by rotating the pipe element about a longitudinal axis while forcing a grooved roller against the pipe element so as to displace material of the pipe element; While rotating the pipe element, measuring the circumference of the groove; The diameter of the slot is determined by using the circumference of the slot; Compare the groove diameter to the desired tolerance range; The steps of forcing, measuring, determining and comparing are repeated until the groove diameter is within the desired tolerance range.

[0006] The exemplary method may further include: Determine the diameter of the piping components; comparing the diameter of the piping element to a tolerance range for the diameter of the piping element; If the diameter of the pipe element is not within the tolerance range for the diameter of the pipe element, the pipe element is rejected before the groove is formed in the pipe element.

[0007] In a specific example of the method, determining the diameter of the pipe element may include: causing the pipe element to rotate when the pipe element engages the grooving roller, the grooving roller rotating in response to the pipe element; Knowing the diameter of the surface of the grooved roller that engages the pipe element; Determine the number of revolutions of the grooving roller per revolution of the pipe element, including fractional parts thereof; and Calculate the diameter of the pipe element, the number of revolutions of the grooving roller, including its fractional part, the number of revolutions per revolution of the pipe element is proportional to the diameter of the pipe element.

[0008] For example, determining the number of revolutions of the grooving roller, including fractional parts thereof, may include counting the number of revolutions of the grooving roller, including fractional parts thereof, for at least one revolution of the pipe element.

[0009] In an exemplary method embodiment, determining at least one turn of the pipeline element is accomplished by: marking an outer surface of the pipe element with a light reflective surface that contrasts with the outer surface of the pipe element; shining light onto an outer surface of the pipe element; When the pipe element is rotated, first and second reflections of the light from the light reflecting surface are sensed.

[0010] In certain exemplary embodiments, engaging the grooving roller with the pipe element includes squeezing the pipe element between the grooving roller and the drive roller using sufficient force to secure the pipe element therebetween. An exemplary embodiment of the method includes engaging an inner surface of the pipe element with the drive roller and engaging an outer surface of the pipe element with the grooving roller.

[0011] For example, the method may further include selecting a rotational speed for rotating the pipe element based on at least one characteristic of the pipe element. The at least one characteristic of the pipe element may be selected from the group consisting of: diameter, wall thickness and material of the pipe element and combinations thereof.

[0012] Similarly, for example, the method may further include selecting a force for urging the grooving roller against the pipe element based on at least one characteristic of the pipe element. The at least one characteristic of the pipe element may be selected from the group consisting of: diameter, wall thickness and material of the pipe element and combinations thereof.

[0013] Again by way of example, the method may include selecting a feed rate of a grooving roller for forming a groove in the pipe element based on at least one characteristic of the pipe element. The at least one characteristic of the pipe element may be selected from the group consisting of: diameter, wall thickness and material of the pipe element and combinations thereof.

[0014] In an exemplary embodiment of the method, determining the diameter of the groove includes: Knowing the diameter of the surface of the grooving roller that engages the groove in the pipe element; Determine the number of revolutions of the grooving roller per revolution of the pipe element, including fractional parts thereof; Calculate the groove diameter, the number of revolutions of the grooving roller, including its fractional part, the number of revolutions per revolution of the pipe element is proportional to the groove diameter.

[0015] Furthermore, for example, determining the number of revolutions of the grooving roller, including fractional parts thereof, includes counting the number of revolutions of the grooving roller, including fractional parts thereof, for at least one revolution of the pipe element.

[0016] In an exemplary embodiment, determining at least one turn of the pipe element may be accomplished by: marking an outer surface of the pipe element with a light reflective surface that contrasts with the outer surface of the pipe element; shining light onto an outer surface of a pipe element; When the pipe element is rotated, first and second reflections of the light from the light reflecting surface are sensed.

[0017] Additionally, the exemplary method may further include measuring a plurality of dimensions proximate to the circumferential groove in the pipe element when the pipe element is rotated. In an exemplary embodiment, measuring the plurality of dimensions includes measuring at least one dimension selected from the group consisting of: a distance from an end of the groove to an end of the pipe, a width of the groove, a depth of the groove, a flattened height of the pipe, and combinations thereof.

[0018] The present invention also encompasses a method for processing a pipe element having a longitudinal axis by using a drive roller and an idler roller. In an exemplary embodiment, the method comprises: determining the diameter of the pipe element by the following steps: engaging the pipe element with the drive roller; engaging the idler roller with the pipe element; rotating the pipe element about the longitudinal axis when the pipe element engages the idler roller, the idler roller rotating in response to the pipe element; knowing the diameter or circumference of the surface of the idler roller that engages the pipe element; Determine the number of revolutions of the idler roller per revolution of the piping element, including fractional parts thereof; and The number of revolutions of the idler roller per revolution of the pipe element, including fractional parts thereof, is used to calculate the diameter of the pipe element.

[0019] In this example, determining the number of revolutions of the idler roller, including fractional portions thereof, may include counting the number of revolutions of the idler roller, including fractional portions thereof, for at least one revolution of the pipe element.

[0020] The exemplary method may further include: comparing the diameter of the piping element to a tolerance range for the diameter of the piping element; If the diameter of the pipe element is not within the tolerance range of the diameter of the pipe element, the pipe element is rejected.

[0021] For example, at least one turn of a pipe element may be determined by the following steps: marking an outer surface of the pipe element with a light reflective surface that contrasts with the outer surface of the pipe element; shining light onto an outer surface of the pipe element; When the pipe element is rotated, first and second reflections of the light from the light reflecting surface are sensed.

[0022] In another exemplary embodiment, at least one turn of the pipe element may be determined by: positioning a magnet on a surface of the pipe element; When the pipe element is rotated, the first magnetic field and the second magnetic field are sensed.

[0023] In certain exemplary embodiments, an idler roller may be used as a grooving roller to form a circumferential groove in a pipe element about a longitudinal axis by: forcing the grooving rollers against the pipe element to displace material of the pipe element while rotating the pipe element; measuring the circumference of the groove while rotating the pipe element; The diameter of the slot is determined by using the circumference of the slot; comparing the diameter of the groove to a tolerance range for the diameter of the groove; The steps of forcing, measuring, determining and comparing are repeated until the diameter of the groove is within tolerance.

[0024] For example, measuring the circumference of a slot while rotating a pipe element may include: Know the diameter or circumference of the surface of the grooved roll that engages the groove; Determine the number of revolutions of the grooving roller per revolution of the pipe element and its fractional part; and The circumference of the groove is calculated by using the diameter or circumference of the surface and the number of revolutions of the grooving roller per revolution of the pipe element and its fractional portion.

[0025] In a specific example, determining the number of revolutions of the grooving roller and fractional parts thereof includes counting the number of revolutions of the grooving roller and fractional parts thereof for at least one revolution of the pipe element.

[0026] Another example includes determining at least one revolution of the pipe element by sensing a feature on the pipe element a first time and a second time while rotating the pipe element.

[0027] As another example, at least one turn of the pipe element may be determined by the following steps: marking an outer surface of the pipe element with a light reflective surface that contrasts with the outer surface of the pipe element; shining light onto an outer surface of the pipe element; When the pipe element is rotated, first and second reflections of the light from the light reflecting surface are sensed.

[0028] In another example, at least one turn of the pipe element may be determined by: positioning a magnet on a surface of the pipe element; When the pipe element is rotated, the first magnetic field and the second magnetic field are sensed.

[0029] In another exemplary embodiment, a grooving roller may be used to form a circumferential groove in a pipe element about a longitudinal axis by: forcing the grooving rollers against the pipe element to displace material of the pipe element while rotating the pipe element; While rotating the pipe element, measuring the circumference of the groove; The diameter of the slot is determined by using the circumference of the slot; comparing the diameter of the groove to a tolerance range for the diameter of the groove; The steps of forcing, measuring, determining and comparing are repeated until the diameter of the groove is within tolerance.

[0030] In certain embodiments, measuring the circumference of the slot while rotating the pipe element may include: engaging the idler roller with the pipe element within the groove; Know the diameter or circumference of the surface of the idler roller that engages the pipe element within the groove; Determine the number of revolutions of the idler roller per revolution of the piping element and its fractional portion thereof; and The circumference of the groove is calculated by using the diameter or circumference of the surface and the number of revolutions of the idler roller per revolution of the pipe element and its fractional portion.

[0031] As another example, determining the number of revolutions of the idler roller and the fractional portion thereof may include counting the number of revolutions of the idler roller and the fractional portion thereof for at least one revolution of the pipe element.

[0032] Another exemplary embodiment may include determining at least one turn of the pipe element by: marking an outer surface of the pipe element with a light reflective surface that contrasts with the outer surface of the pipe element; shining light onto an outer surface of the pipe element; When the pipe element is rotated, first and second reflections of the light from the light reflecting surface are sensed.

[0033] As another example, at least one turn of the pipe element may be determined by the following steps: positioning a magnet on a surface of the pipe element; When the pipe element is rotated, the first magnetic field and the second magnetic field are sensed.

[0034] The present invention further encompasses a device for forming a circumferential groove in a pipe element having a longitudinal axis. In an exemplary embodiment, the device includes a drive roller rotatable about a drive roller axis. When the drive roller axis is oriented substantially parallel to the longitudinal axis of the pipe element, the drive roller can engage the inner surface of the pipe element. The grooved roller can rotate about a grooved roller axis oriented substantially parallel to the drive roller axis. The grooved roller has a known diameter. The grooved roller can move toward and away from the drive roller so as to forcibly engage the outer surface of the pipe element so as to form a groove therein when the pipe element is rotated. A first sensor is used to determine the degree of rotation of the grooved roller and generate a first signal representing the degree of rotation. A second sensor is used to determine the degree of rotation of the pipe element and generate a second signal representing the degree of rotation. A control system is adapted to receive the first signal and the second signal, use the first signal and the second signal to determine the diameter of the groove, and control the movement of the grooved roller toward and away from the drive roller in response to the diameter of the groove.

[0035] For example, the first signal may include a rotary encoder that is operatively associated with the grooving roller. Also for example, the second sensor may include a light reflecting surface adhered to the outer surface of the pipe element. The light reflecting surface is in contact with the outer surface of the pipe element. The light projector is positioned to project light onto the outer surface of the pipe element and the light reflecting surface adhered to the outer surface. The detector is adapted to detect the light projected by the light projector when reflected from the light reflecting surface, and the detector generates a signal representing the projected light. For example, the light projector may include a laser. Further in the example, the light reflecting surface may be selected from the group consisting of the following surfaces: a specular reflective surface, a diffuse reflective surface, a contrasting color reflective surface, and a combination thereof. In another exemplary embodiment, the second sensor includes a magnet adhered to the surface of the pipe element. The detector is adapted to detect a magnetic field. The detector generates a signal representing the magnetic field. In another exemplary embodiment, the device may also include a third sensor for measuring the surface profile of at least a portion of the pipe element and generating a signal representing the surface profile. For example, the third sensor may include a laser that is adapted to project a fan-shaped light beam along at least a portion of the pipe element. The detector receives a reflection of the fan-shaped light beam from a portion of the pipe element. The computer unit converts the reflections into measurements representing the surface profile by using triangulation. The computer unit then generates a signal representing the measurement and transmits the signal to a control system.

[0036] For example, the grooving rolls may be mounted on actuators that are controlled by a control system, the actuators comprising, for example, a hydraulic pump.

[0037] The present invention further encompasses a device for forming a circumferential groove in a pipe element having a longitudinal axis. In an exemplary embodiment, the device includes a drive roller rotatable about a drive roller axis. When the drive roller axis is oriented substantially parallel to the longitudinal axis of the pipe element, the drive roller can engage the inner surface of the pipe element. The grooved roller can rotate about a grooved roller axis oriented substantially parallel to the drive roller axis. The grooved roller can move toward and away from the drive roller so as to forcibly engage the outer surface of the pipe element so as to displace the material of the pipe element and form a groove therein when the pipe element is rotated. The idler roller can rotate about an idler roller axis oriented substantially parallel to the drive roller axis. The idler roller has a known diameter. The idler roller can move toward and away from the drive roller so as to engage the outer surface of the pipe element so as to rotate when the pipe element is rotated. The first sensor determines the degree of rotation of the idler roller and generates a first signal representing the degree of rotation. The second sensor determines the degree of rotation of the pipe element and generates a second signal representing the degree of rotation. The control system is adapted to receive the first signal and the second signal and use the first signal and the second signal to determine a diameter of the groove and to control movement of the grooved roller toward and away from the drive roller in response to the diameter of the groove.

[0038] In a particular exemplary embodiment, the first sensor includes a rotary encoder operatively associated with the idler roller. As another example, the second sensor may include a light reflecting surface adhered to an outer surface of the pipe element. The light reflecting surface is in contact with the outer surface of the pipe element. The light projector is positioned to project light onto the outer surface of the pipe element and the light reflecting surface adhered to the outer surface. The detector is adapted to detect light projected by the light projector when reflected from the light reflecting surface, the detector generating a signal representative of the projected light. The light projector may, for example, include a laser.

[0039] In another exemplary embodiment, the second sensor may include a magnet adhered to the surface of the pipe element. The detector is adapted to detect the magnetic field. The detector generates a signal representative of the magnetic field. The exemplary apparatus may further include a third sensor for measuring a surface profile of at least a portion of the pipe element and generating a signal representative of the surface profile. In a particular exemplary embodiment, the third sensor includes a laser adapted to project a fan-shaped beam along at least a portion of the pipe element. The detector is adapted to receive reflections of the fan-shaped beam from a portion of the pipe element. The calculator unit converts the reflections into a measurement value representative of the surface profile by using triangulation. The sensor generates a signal representative of the measurement value and transmits the signal to a control system.

[0040] In certain exemplary embodiments, the grooved rollers are mounted on actuators controlled by the control system. Similarly, for example, the idler rollers may be mounted on actuators controlled by the control system.

[0041] In another exemplary embodiment, a device for forming a circumferential groove in a pipe element having a longitudinal axis includes a drive roller rotatable about a drive roller axis. When the drive roller axis is oriented substantially parallel to the longitudinal axis of the pipe element, the drive roller can engage the inner surface of the pipe element. A grooved roller can rotate about a grooved roller axis oriented substantially parallel to the drive roller axis, the grooved roller having a known diameter. The grooved roller can move toward and away from the drive roller to forcibly engage the outer surface of the pipe element and form a groove therein when the pipe element is rotated. A sensor is used to measure a surface profile of at least a portion of the pipe element and generate a signal representing the surface profile. A control system adapted to receive the signal uses the signal to determine a diameter of the groove and controls movement of the grooved roller toward and away from the drive roller in response to the diameter of the groove.

[0042] In certain exemplary embodiments, the sensor includes a laser adapted to project a fan-shaped light beam along at least a portion of the pipe element. The detector receives reflections of the fan-shaped light beam from a portion of the pipe element. The calculator unit converts the reflections into measurements representing a surface profile by using triangulation, generates a signal representing the measurements, and transmits the signal to a control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 and Figure 1A is an isometric view of an exemplary embodiment of an apparatus for forming a circumferential groove in a pipe element; Figure 2 yes Figure 1 An isometric view of a portion of the device shown in; Figure 3 , Figure 3A , Figure 4 and Figure 5 yes Figure 1 A cross-sectional view of a portion of the device shown in FIG. Figure 6 is a flow chart illustrating an exemplary method of forming a circumferential groove in a pipe element; Figure 7 yes Figure 1 A cross-sectional view of a portion of the device shown in FIG. Figure 8 is a longitudinal cross-sectional view of a pipe element having a perimeter groove, and Figure 9-17 This diagram is used in Figure 8 A flow chart of an exemplary method of forming a groove in a piping element is shown in FIG. DETAILED DESCRIPTION

[0044] Figure 1An exemplary embodiment of an apparatus 10 for forming a circumferential groove in a pipe element is shown. The apparatus 10 includes a drive roller 12 rotatable about an axis 14. In this example, the drive roller 12 is rotated about the axis 14 by a motor 16 positioned within a housing 18 on which the drive roller is mounted. The drive roller 12 has an outer surface 20 that can engage the inner surface of the pipe element, as described below. In this exemplary embodiment, the idler roller is a grooved roller 22, which is also mounted on the housing 18 for rotation about an axis 24. The axis 14 and the axis 24 are generally parallel to each other, which allows the axis 14 and the axis 24 to cooperate when forming the circumferential groove.

[0045] The grooved roller 22 is mounted to the housing 18 via a yoke 26 which allows the grooved roller to move in the direction indicated by arrow 28 toward and away from the drive roller while maintaining the shaft 14 and shaft 24 in a generally parallel relationship. Movement of the yoke 26, and therefore the grooved roller 22, is achieved by an actuator 30. Hydraulic actuators are advantageous because they provide a large range of high forces that can be adjusted in small increments, which can locally bend the pipe material to gradually form a groove. Of course other types of actuators are also possible.

[0046] As in Figure 2 , the apparatus further includes a first sensor 32 for determining the degree of rotation of the grooving roller 22 about the axis 24 during the formation of the circumferential groove in the pipe element. In the present exemplary embodiment, the first sensor 32 comprises a rotary encoder. Rotary encoders are advantageous because they have excellent reliability, reproducibility, accuracy and resolution, typically allowing the rotation to be divided into 600,060 discrete steps for better accuracy in measuring the rotation of the grooving roller 22. A rotary encoder model LM101C005BB20F00 supplied by RLS of Ljubljana, Slovenia, is used as a practical example suitable for the apparatus 10.

[0047] Typically, at least one revolution of the pipe element can be determined by sensing a feature on the pipe element for a first time and a second time while rotating the pipe element. For example, the feature can be a naturally occurring feature, such as a unique scratch, tool mark, seam, or other feature that is not placed on the pipe for any special purpose. However, it is advantageous to place an easily detectable feature on the pipe element to ensure that the rotation of the pipe element is reliably and accurately detected. Two examples are described below, and it should be understood that other detection methods are also possible.

[0048] Refer again Figure 1 , the device 10 comprises a second sensor 34 for detecting the degree of rotation of the pipeline element. Figure 3A second sensor 34 is shown, which includes a light projector 36 (e.g., a laser), a detector 38 that detects light from the light projector when the light is reflected from a pipe element 40, and a light reflective surface 42 that is adhered to an outer surface 40b of the pipe element 40. The light reflective surface 42 may be a specular reflective surface, a diffuse reflective surface, or have a different color than the light reflective surface of the outer surface 40b of the pipe element 40 and thus provide a contrast to the outer surface of the pipe element. The sensor 34 is also referred to as a contrast sensor because the detector 38 detects the difference between the projected light reflected by the pipe outer surface 40b and the projected light reflected by the contrast light reflective surface 42. A contrast sensor such as 34 is manufactured by Leuze Electronics, Inc., New Hudson, Michigan, Model HRTL 3B / 66-S8, and may be used with the apparatus 10 disclosed herein. Each time the light reflective surface 42 passes under the light from the light projector 36, the detector detects the reflection from the light reflective surface 42 and generates a signal that may be used to detect and count the number of revolutions of the pipe element.

[0049] In an alternative embodiment, Figure 3A , the second sensor 34 may include a magnetic sensor 35. The magnetic sensor 35 is also a non-contact proximity sensor that uses inductive or capacitive principles to sense the passage of a magnet 37 adhered to a surface (e.g., the outer surface 40b of the pipe element 40). Each time the magnet 37 passes through the magnetic sensor 35, a signal is generated that can be used to detect and count the number of revolutions of the pipe element.

[0050] As in Figure 1 As shown in FIG. 1 , the device 10 may also have a third sensor 46 for measuring the surface profile of at least a portion of the pipe element. Figure 7 , the third sensor 46 is a triangulation sensor and includes a laser 48 adapted to generate a fan-shaped beam 50 along a portion of the outer surface 40b of the pipe element 40 where a profile 52 is to be measured. A detector 54 is adapted to receive reflections of the fan-shaped beam from the outer surface portion of the pipe element. The third sensor 46 also includes a calculator unit 55 that uses triangulation to convert the reflections of the fan-shaped beam into a measurement value representative of the outer surface profile.

[0051] Refer again Figure 1, the device 10 also includes a control system 56. The control system 56 is in communication with the sensors 32, 34, 46, as well as the motor 16 and the actuator 30. This communication may be achieved through dedicated wires 58. The control system receives the signals generated by the sensors 32, 34, and 46 and sends commands to the actuator 30 and the motor 16 to control the operation of the various parts of the device 10 to form the grooves in the pipe element. The sensor 32 generates a signal indicative of the rotation of the grooving roller 22; the sensor 34 generates a signal indicative of the rotation of the pipe element 40 (see also Figure 3 ); and the sensor 46 generates a signal representing the outer surface profile of the pipe element 40 (see also Figure 7 ). These signals are transmitted to the control system. The control system 56 may include a computer or programmable logic controller with resident software that interprets the signals from the sensors 32, 34, and 46 and then sends commands to the actuator 30 and the motor 16 to initiate a plurality of functions associated with forming the circumferential groove in the pipe element. The control system 56, the actuator 30, the motor 16, and the sensors 32, 34, and 46 operate together in a feedback loop to automatically form the groove in the operation described below.

[0052] Figure 1A Device 10a is shown with a second idler roller 23, which is spaced from idler roller 22. In this exemplary embodiment, idler roller 22 is a grooved roller mounted on yoke 26 as described above, and second idler roller 23 is mounted on actuator 25, which is mounted on device 10a. Actuator 25 is controlled by control system 56 and moves idler roller 23 toward and away from drive roller 12 to engage and disengage engagement between idler roller 23 and a pipe element. Idler roller 23 is rotatable about axis 27, which is generally parallel to axis 14, and will rotate about axis 27 when engaged with a pipe element mounted on and rotated by drive roller 12. In this embodiment, idler roller 23 is used to determine pipe element diameter and slot diameter, and idler (grooved) roller 22 is used to support the pipe element and form a circumferential slot. To this end, a first sensor 32 is operatively associated with the idler roller 23 and is used to determine the extent of rotation of the idler roller 23 about the axis 27 during the determination of the diameter of the pipe element and the formation of the circumferential groove in the pipe element. In the present exemplary embodiment, the first sensor 32 may again include a rotary encoder as described above. The rotary encoder counts the number of revolutions of the idler roller 23 and fractions thereof and generates a signal representative of the number of revolutions and fractions thereof, which is transmitted to the control system 56 via a communication link such as a hardwired wire 58. The control system 56 uses the information transmitted in the signal to determine the diameter of the pipe element and to control the machine operation during the formation of the groove as described below.

[0053] Device Operation An exemplary method for forming a circumferential groove in a pipe element by using the apparatus 10 is described in Figure 1-5 Neutral Figure 6 As shown in the flowchart of Figure 3 As shown in FIG. 1 , the pipe element 40 engages the drive roller 12 (see box 62, Figure 6 ). In this example, the inner surface 40a of the pipe element 40 is placed in contact with the drive roller. Figure 6 As described in block 64 of the apparatus 10, the grooving roller 22 is moved toward the drive roller 12 by the actuator 30 (under the command of the control system 56) until it engages the outer surface 40b of the pipe element 40. Advantageously, the pipe element 40 is squeezed between the drive roller 12 and the grooving roller 22 with sufficient force to securely secure the pipe element to the apparatus 10. At this point, the diameter of the pipe element 40 can be determined so that the pipe element is accepted and the circumferential groove is formed, or the pipe element is rejected because the diameter of the pipe element is outside of an acceptable tolerance range and is therefore incompatible with other pipe elements of the same nominal size. The pipe element diameter is determined by Figure 6 66 in and is achieved by measuring the circumference of the pipe while rotating the pipe element 40 about its longitudinal axis 68 using the drive roller 12 powered by the motor 16. The drive roller 12 in turn rotates the pipe element 40, which causes the grooved roller 22 to rotate about its axis 24. In order to make the measurement more accurate, it is advantageous that the grooved roller 22 rotates in response to the pipe element 40 and does not slip. The diameter of the pipe element 40 can then be calculated by: knowing the diameter of the surface 22a of the grooved roller 22 that contacts the pipe element 40; and counting the number of revolutions of the grooved roller for each revolution of the pipe element, including fractional portions of the revolution. If the diameter D of the grooved roller surface 22a is known, the circumference C of the pipe element 40 can be calculated from the relationship C=(DxrevxΠ), where "rev" equals the number of revolutions of the grooved roller 22 for each revolution of the pipe element, including fractional portions of the revolution. Once the circumference C of the pipe element is known, the pipe element diameter d can be calculated from the relationship d=C / Π.

[0054] In the device 10, the sensor 32 (e.g., a rotary encoder) counts the number of revolutions and fractions thereof (rev) of the grooved roller 22 and generates a signal representing the number of revolutions and fractions thereof (rev). The number of revolutions per revolution of the pipe element 40 is detected and / or counted by the sensor 34, which generates a signal representing the number of revolutions per revolution of the pipe element 40. For example, if the sensor 34 is a control sensor as described above (see Figure 3 ), the sensor 34 senses the first and second reflections from the light reflecting surface 42, which indicates that it has detected or counted one rotation of the pipe element. If the sensor 34 is a magnetic sensor ( Figure 3A ), the sensor 34 senses the first magnetic field and the second magnetic field, which indicates that it has detected or counted one rotation of the pipe element. The signals from the sensors 32 and 34 are transmitted to the control system 56, which performs calculations to determine the diameter of the pipe element 40. The control system can then display the pipe element diameter to the operator for acceptance or rejection, or the control system itself can compare the pipe element diameter with the tolerance range of the pipe of known nominal size and display an "accept" or "reject" signal to the operator. Note that for this automatic operation, the control system is programmed with dimensional tolerance data for pipe elements of multiple standard sizes. The operator must install a grooving roller suitable for the standard pipe size and the groove formed and input the specific standard pipe element being processed into the control system. The resident software within the control system will then respond to these inputs and use the appropriate reference data to determine whether the pipe element has an acceptable tolerance range for the selected standard size of pipe elements.

[0055] Figure 6 Box 70 and Figure 4 The groove 72 is shown formed in the pipe element 40. Thus, the drive roller 12 is rotated by rotating the pipe element 40 about its longitudinal axis 68, which rotates the grooved roller 22 about the axis 24. Note that the rotation axis 14 of the drive roller 12, the rotation axis 24 of the grooved roller 22, and the longitudinal axis 68 of the pipe element 40 are generally parallel to each other. As used herein, "generally parallel" means within about 2 degrees to allow rotation without significant friction but to allow the generation of traction forces that keep the pipe element engaged with the drive roller and the grooved roller during rotation. During the rotation of the pipe element, the actuator 30 ( Figure 1 ) forces the grooved roller 22 against the pipe element 40, thereby cold working the pipe element. Note that the force applied by the actuator 30, as well as the feed rate of the grooved roller 22 (i.e., the rate at which the grooved roller moves toward the drive roller) and the rotational speed of the pipe element can be selected based on one or more characteristics of the pipe element 40. These characteristics include, for example, pipe element diameter, wall thickness (plan), and the material comprising the pipe element. The selection of operating parameters such as force, feed rate, and rotational speed can be established by the operator or by the control system 56 in response to input from the operator indicating the specific pipe being processed. For example, the controller can have a database of preferred operating parameters associated with specific standard pipe elements based on diameter, plan, and material.

[0056] To achieve compatibility between the pipe element 40 and the mechanical coupling, the final diameter 74b of the groove 72 (see Figure 5 ) needs to be within acceptable tolerances for the particular diameter pipe element being processed. As indicated in block 76 (see also Figure 4), in order to produce an acceptable groove 72, the instantaneous groove diameter 74a (i.e., the groove diameter before the final diameter is achieved) is determined during the interval when the pipe element 40 is rotated. Figure 4 As shown in FIG. 1 , by using the diameter of the pipe element 40 as described above for determining the diameter of the pipe element 40 ( Figure 6 , box 66) to determine the instantaneous groove diameter 74a. The signals from the sensor 32 (which represents the number of revolutions of the groove roll 22 and its fractional portion) and the signals from the sensor 34 (which represents the number of revolutions of the pipe element) continue to measure the instantaneous circumference of the pipe element 40 within the groove 72. These signals are transmitted to the control system 56, which uses the information in the signals to determine (i.e., calculate) the instantaneous diameter 74a of the groove 72 (note that the diameter of the surface 22a of the groove roll 22 that forms the groove is known). As shown in box 78, the control system then compares the instantaneous diameter of the groove with the appropriate tolerance range for the groove diameter for the particular pipe being processed. As shown in block 80, if the instantaneous groove diameter is not within the appropriate tolerance range, e.g., the instantaneous groove diameter is greater than the maximum acceptable diameter for the particular pipe element being processed, the control system 56 continues to form the groove 72 by rotating the pipe element 40 about its longitudinal axis 68 while forcing the groove rollers 22 against the pipe element to displace material of the pipe element, determining the instantaneous diameter 74a of the groove 72 while rotating the pipe element 40, and comparing the instantaneous groove diameter to the tolerance range for the groove diameter until the groove diameter is within the acceptable tolerance range for the groove diameter.

[0057] Once the final groove diameter 74b is at the predetermined target diameter, the control system 56 stops moving the grooving roller 22 toward the drive roller 12, but continues to rotate the pipe element at least one full revolution to ensure uniform grooving depth. The rotation is then stopped and the grooving roller 22 moves away from the drive roller 12 so that the pipe element 40 can be removed from the device 10.

[0058] Another exemplary method described is for using Figure 1A 10a is used to form a circumferential groove in a pipe element. This embodiment has two separate idler rollers: idler roller 22, which is a grooved roller; and idler roller 23, which is a measuring roller. As described above, the pipe element engages with the drive roller 12 (see box 62, Figure 6 ). Then, as in Figure 6As described in block 64 of , the grooved roller 22 is moved toward the drive roller 12 by the actuator 30 (under the command of the control system 56) until it engages the outer surface of the pipe element. It is advantageous to use sufficient force to squeeze the pipe element between the drive roller 12 and the grooved roller 22 so as to securely secure the pipe element to the device 10. The control system 56 also commands the actuator 25 to move the idler roller 23 into engagement with the outer surface of the pipe element. At this point, the diameter of the pipe element can be determined so that the pipe element is accepted and the circumferential groove is formed, or the pipe element is rejected because the diameter of the pipe element is outside of an acceptable tolerance range and is therefore incompatible with other pipe elements of the same nominal size. The pipe element diameter is determined by Figure 6 66 in and is accomplished by measuring the circumference of the pipe while rotating the pipe element about its longitudinal axis using a drive roller 12 powered by a motor 16. The drive roller 12 in turn rotates the pipe element, which causes the idler roller 23 to rotate about its axis 27. For greater accuracy of measurement, it is advantageous that the idler roller 23 rotates in response to the pipe element and does not slip. The diameter of the pipe element can then be calculated by: knowing the diameter of the surface of the idler roller 23 that contacts the pipe element; and counting the number of revolutions, including fractional portions of revolutions, of the idler roller 23 for each revolution of the pipe element. If the diameter D of the idler roller 23 is known, the circumference C of the pipe element can be calculated from the relationship C=(D x rev x Π), where "rev" equals the number of revolutions, including fractional portions of revolutions, of the idler roller 23 for each revolution of the pipe element. Once the circumference C of the pipe element is known, the pipe element diameter d can be calculated from the relationship d=C / Π.

[0059] In the device 10a, the sensor 32 (e.g., a rotary encoder) counts the number of revolutions of the idler roller 23 and fractions thereof and generates a signal representing the number of revolutions and fractions thereof. The number of revolutions per revolution of the pipe element is detected and / or counted by the sensor 34 (e.g., a contrast sensor or a magnetic sensor), which generates a signal representing the number of revolutions per revolution of the pipe element. The signals from the sensors 32 and 34 are transmitted to the control system 56, which performs calculations to determine the diameter of the pipe element. The control system can then present the pipe element diameter to the operator for acceptance or rejection, or the control system itself can compare the pipe element diameter to the tolerance range of a pipe of a known nominal size and present an "accept" or "reject" signal to the operator.

[0060] Figure 6Frame 70 of illustrative embodiment illustrates the formation of a groove in a pipe element. Thus, the drive roller 12 is rotated by rotating the pipe element about its longitudinal axis (which rotates the grooved roller 22 about the axis 24 and the idler roller 23 about its axis 27). Note that the rotation axis 14 of the drive roller 12, the rotation axis 24 of the grooved roller 22, the rotation axis 27 of the idler roller 23, and the longitudinal axis of the pipe element are generally parallel to each other. During the rotation of the pipe element, the actuator 30 forces the grooved roller 22 against the pipe element, thereby cold working the pipe element, displacing the pipe element material, and forming a circumferential groove. Also during the rotation of the pipe element, the actuator 25 causes the idler roller 23 to maintain contact with the pipe element within the groove formed by the use of the grooved roller 22.

[0061] To achieve compatibility between the pipe element and the mechanical coupling, the final diameter of the groove needs to be within acceptable tolerances for the particular diameter pipe element being processed. As represented in block 76, in order to produce an acceptable groove, the instantaneous groove diameter (i.e., the groove diameter before the final diameter is achieved) is determined during the interval when the pipe element is rotated. By using the diameter of the pipe element ( Figure 6 , box 66) to determine the instantaneous groove diameter. The signals from sensor 32 (which represents the number of revolutions of the idler roller 23 and its fractional portion) and the signals from sensor 34 (which represents the number of revolutions of the pipe element) continue to measure the instantaneous circumference of the pipe element within the groove formed by the groove roller 22. These signals are transmitted to the control system 56, which uses the information in the signals to determine (i.e., calculate) the instantaneous diameter of the groove (note that the diameter of the idler roller 23 in contact with the pipe element is known). As shown in box 78, the control system then compares the instantaneous diameter of the groove with the appropriate tolerance range for the groove diameter for the particular pipe being processed. As shown in box 80, if the instantaneous groove diameter is not within the appropriate tolerance range, for example, the instantaneous groove diameter is greater than the maximum acceptable diameter for the particular pipe element being processed, then the control system 56 continues to form the groove by rotating the pipe element about its longitudinal axis while forcing the groove rollers 22 against the pipe element to displace material of the pipe element, determining the instantaneous diameter of the groove while rotating the pipe element (via the idler rollers 23 and their associated sensors 32), and comparing the instantaneous diameter of the groove to the tolerance range for the groove diameter until the groove diameter is within the acceptable tolerance range for the groove diameter.

[0062] Once the final groove diameter is at the predetermined target diameter, the control system 56 stops moving the groove roll 22 toward the drive roll 12, but continues to rotate the pipe element at least one full revolution to ensure uniform groove depth. The rotation is then stopped and the groove roll 22 and idler roll 23 move away from the drive roll 12 so that the pipe element can be removed from the device 10a.

[0063] As in Figure 7 As shown in FIG. 1 , the triangulation sensor 46 may also be used to measure multiple dimensions of the pipe element 40 proximate the slot 72. Figure 8 , dimensions such as the distance 88 from the end of the pipe 40 to the groove 72, the width 90 of the groove, the depth 92 of the groove, and the flattened height 94 of the pipe element can be measured to create a profile of the pipe end. Flattening can occur due to the grooving process, and the flattened height is the height of the end of the pipe element above the pipe diameter. This information can be transmitted to the control system for comparison with the acceptable tolerances for these dimensions for standard pipe elements.

[0064] As in Figure 7 and Fig. 9 As described in , the measurement of multiple dimensions is achieved while rotating the pipe element and includes: measuring along the length of the surface of the pipe element 40 (which includes the circumferential groove 72 (see Fig. 9 , box 96). The reflection of the beam 50 is detected by the sensor 54 (box 98). The calculator unit 55 operatively associated with the sensor 54 uses trigonometric methods to calculate the size of the area of ​​the pipe element 40 swept by the beam 50 (box 100). The size information is encoded into a signal, which is transmitted (in this example via hardwired wires 58) to the control system 56 (see Figure 1 ). The dimension signals thus acquired can be displayed in a database and / or evaluated in order to characterize the pipeline element as processed.

[0065] FIG. 10 illustrates another exemplary method for forming a circumferential groove in a pipe element having a longitudinal axis and using a drive roller and a grooving roller, the exemplary method comprising: engaging a pipe element with a drive roller (block 102); engaging a grooving roller with a pipe element (block 104); forming a groove by rotating the pipe element about a longitudinal axis while forcing a grooved roller against the pipe element so as to displace material of the pipe element (block 106); measuring a plurality of circumferences of the groove while rotating the pipe element (block 108); determining a plurality of diameters of the groove by using a plurality of perimeters of the groove (block 110); Calculating the change in diameter of the groove per revolution of the pipe element (block 112); calculating the number of revolutions of the pipe element required to form a groove of a desired diameter by using the change in diameter of the groove per revolution (block 114); Counting the number of revolutions of the conduit element (block 116); and When the number of revolutions required to form a groove of the desired diameter is reached, forcing the grooving rollers against the pipe element is stopped (block 118).

[0066] The method shown in Figure 10 is a predictive method that uses the rate of change of diameter per revolution of the pipe element to predict when to stop forming the groove by displacing material of the pipe element. Since this prediction may not produce the groove diameter as accurately as desired, additional steps as shown below may be advantageous: measuring the diameter of the slot (block 120); comparing the diameter of the slot to a desired diameter (block 122); The forming, measuring, determining, calculating, counting and stopping steps are repeated (block 124).

[0067] FIG. 11 shows a similar prediction-correction method for forming a groove. However, the method is based on the circumference of the groove rather than the diameter. In a specific example, the method includes: engaging the pipe element with the drive roller (block 126); engaging a grooving roller with a pipe element (block 128); forming a groove by rotating the pipe element about a longitudinal axis while forcing a grooved roller against the pipe element so as to displace material of the pipe element (block 130); measuring a plurality of circumferences of the groove while rotating the pipe element (block 132); Calculating the change in circumference of the slot per revolution of the conduit element (block 134); calculating the number of revolutions of the conduit element required to form a groove of a desired circumference by using the change in circumference per revolution of the conduit element (block 136); Counting the number of revolutions of the conduit element (block 138); and When the number of revolutions required to form a groove of the desired circumference is reached, forcing the grooving rollers against the pipe element is stopped (block 140).

[0068] Again, to correct for the inaccurate slots formed by using predictions, the following steps can be added: measuring the circumference of the slot (block 142); comparing the circumference of the slot to a desired circumference (block 144); The forming, measuring, calculating, counting and stopping steps are repeated (block 146).

[0069] The methods described so far have all used a generally continuous rate (the rate at which the grooved rollers move toward the pipe element). However, if the grooved rollers are advanced in discrete increments, such as in Fig.12 The method described in the figure and as described below may be advantageous in terms of efficiency and accuracy: engaging the pipe element with the drive roller (block 148); engaging the grooving roller with the pipe element (block 149); forming a groove by rotating the pipe element about a longitudinal axis while forcing a grooved roller into the pipe element discrete distances so that material of the pipe element is displaced by the rotation of the pipe element (block 150); measuring the circumference of the groove while rotating the pipe element (block 152); determining a diameter of the slot by using the perimeter of the slot (block 154); comparing the diameter of the groove to a tolerance range for the diameter of the groove (block 156); and Until the groove diameter is within tolerance: The forming, determining and comparing steps are repeated (block 158).

[0070] It may be further advantageous to vary the size of the discrete distances that the groove rolls move, for example by reducing the discrete distances per revolution as the diameter approaches the tolerance range. This may allow greater accuracy in the groove formation and reduce the time required to form the groove.

[0071] exist Fig.13 The exemplary method described in also uses discrete increments of the distance traveled by the grooved rollers, but controls the grooved rollers based on measurements of the circumference of the grooves, as described below: engaging the pipe element with the drive roller (block 160); engaging a grooving roller with a pipe element (block 162); forming a groove by rotating the pipe element about a longitudinal axis while forcing a grooved roller into the pipe element discrete distances so that material of the pipe element is displaced by the rotation of the pipe element (block 164); measuring the circumference of the groove while rotating the pipe element (block 166); comparing the perimeter of the slot to a tolerance range for the perimeter of the slot (block 168); and Until the slot circumference is within tolerance: The forming, measuring and comparing steps are repeated (block 170).

[0072] Again, it may be further advantageous to vary the size of the discrete distances that the grooving rollers move, for example by reducing the discrete distances per revolution as the diameter approaches the tolerance range. This may allow greater accuracy in the formation of the grooves and reduce the time required to form the grooves.

[0073] exist Fig.14 In the exemplary method shown in , the predictive-corrective aspect is combined with the discontinuous step-by-step motion of the grooving rolls, as described below: engaging the pipe element with the drive roller (block 172); engaging a grooving roller with a pipe element (block 174); forming a groove by rotating the pipe element about the longitudinal axis while forcing a grooved roller into the pipe element discrete distances so that material of the pipe element is displaced by the rotation of the pipe element (block 176); calculating the number of revolutions of the pipe element required to form a groove of a desired diameter by using the discontinuity distance of the groove per revolution (block 178); Counting the number of revolutions of the conduit element (block 180); and When the number of revolutions required to form a groove of the desired diameter is reached, forcing the grooving rollers a discrete distance into the pipe element is stopped (block 182).

[0074] Again, it may be advantageous to Fig.14 Add the following steps to the method shown in measuring the diameter of the slot (block 184); comparing the diameter of the slot to a desired diameter (block 186); The forming, measuring, calculating, counting and stopping steps are repeated (block 188).

[0075] exist Fig.15 In the exemplary method embodiment of Figure 8 ) is used to control the movement of the slotting rollers as described below: engaging the pipe element with the drive roller (block 190); engaging a grooving roller with a pipe element (block 192); measuring a diameter of the pipe element while rotating the pipe element about the longitudinal axis (block 194); Calculating a desired groove depth tolerance corresponding to the desired groove diameter tolerance (block 196); forming a groove by rotating the pipe element about a longitudinal axis while forcing a grooved roller against the pipe element so as to displace material of the pipe element (block 198); While rotating the pipe element, measuring the groove depth (block 200); comparing the groove depth to a desired groove depth tolerance (block 202); and The steps of forming the groove, measuring the groove depth, and comparing the groove depth to a desired groove depth tolerance are repeated until the groove depth is within the desired groove depth tolerance.

[0076] Fig.16 An exemplary method is shown in which the groove diameter is used to control the movement of the grooved rollers as described below: engaging a pipe element with a drive roller (block 205); engaging a grooving roller with a pipe element (block 206); determining a diameter of the pipe element while rotating the pipe element about the longitudinal axis (block 208); determining a desired groove diameter tolerance based on a diameter of the pipe element (block 210); forming a groove by rotating the pipe element about a longitudinal axis while forcing a grooved roller against the pipe element so as to displace material of the pipe element (block 212); determining a groove diameter while rotating the pipe element (block 214); comparing the slot diameter to a desired slot diameter tolerance (block 216); and The steps of forming the groove and determining the groove diameter are repeated until the groove diameter is within a desired groove diameter tolerance (block 218 ).

[0077] Fig.17 An exemplary method is illustrated in which the groove circumference is used to control the movement of the grooved rollers as described below: engaging a pipe element with a drive roller (block 220); engaging a grooving roller with a pipe element (block 224); measuring a circumference of the pipe element while rotating the pipe element about the longitudinal axis (block 226); determining a desired groove circumference tolerance based on the diameter of the pipe element (block 228); forming a groove by rotating the pipe element about a longitudinal axis while forcing a grooved roller against the pipe element so as to displace material of the pipe element (block 230); measuring the groove circumference while rotating the pipe element (block 232); comparing the slot perimeter to a desired slot perimeter tolerance (block 234); The steps of forming the slot, measuring the slot perimeter, and comparing the slot perimeter steps are repeated until the slot perimeter is within a desired slot perimeter tolerance (block 236 ).

[0078] The methods and apparatus disclosed herein provide increased efficiency for forming slotted piping components which reduces the frequency of human error and malformed slots.

Claims

1. A method of forming a circumferential groove in a pipe element having a longitudinal axis using a drive roller and a grooving roller having a known diameter, the method include: engaging a portion of an inner surface of the conduit element with the drive roller; engaging a portion of an outer surface of the pipe element with the grooving roller; forming the groove by rotating the pipe element about the longitudinal axis while forcing the grooved rollers against the pipe element so as to displace material of the pipe element; while rotating the pipe element, measuring the circumference of the groove based on a number of revolutions of the grooving roller determined by sensing features marked on the outer surface; determining a diameter of the groove using the circumference of the groove; comparing the diameter of the groove to a desired tolerance range; The forcing, measuring, determining and comparing steps are repeated until the diameter of the groove is within the desired tolerance range, wherein the drive roller is rotated about a first axis, thereby rotating the pipe element about the longitudinal axis.

2. The method according to claim 1, further comprising: include: determining a diameter of the pipe element; comparing the diameter of the pipe element to a tolerance range for the diameter of the pipe element; If the diameter of the pipe element is not within the tolerance range of the diameter of the pipe element, the pipe element is rejected prior to forming the groove in the pipe element.

3. The method according to claim 2, It is characterized in that Determining the diameter of the pipe element comprises: causing the pipe element to rotate when the pipe element engages the grooving roller, the grooving roller rotating in response to the pipe element; determining the number of revolutions of the grooving roller per revolution of the pipe element, including fractional parts thereof; and The diameter of the pipe element is calculated using the number of revolutions of the grooving roller per one revolution of the pipe element, including the fractional part thereof, and the diameter of the surface of the grooving roller.

4. The method according to claim 3, It is characterized in that Determining the number of revolutions of the grooving roller, including the fractional portion thereof, comprises counting the number of revolutions of the grooving roller, including the fractional portion thereof, for at least one revolution of the pipe element.

5. The method according to claim 4, further comprising: include: The at least one rotation of the pipe element is determined by sensing the characteristic a first time and a second time while rotating the pipe element.

6. The method according to claim 4, further comprising: include: The at least one rotation of the pipe element is determined by: marking the outer surface of the pipe element by using a light reflecting surface that contrasts with the outer surface of the pipe element; shining light onto the outer surface of the pipe element; When the pipe element is rotated, first and second reflections of the light from the light reflecting surface are sensed.

7. The method according to claim 4, further comprising: include: At least one rotation of the pipe element is determined by: marking the outer surface by positioning a magnet on the surface of the pipe element; When the pipe element is rotated, the first magnetic field and the second magnetic field are sensed.

8. The method according to claim 1, It is characterized in that Engaging the grooved roller with the pipe element includes squeezing the pipe element between the grooved roller and the drive roller with sufficient force to secure the pipe element therebetween.

9. The method according to claim 1, further comprising: include: The rotational speed for rotating the pipe element is selected based on at least one characteristic of the pipe element selected from the group consisting of: diameter, wall thickness and material of the pipe element and combinations thereof.

10. The method according to claim 1, further comprising: include: The force used to urge the grooving roller against the pipe element is selected based on at least one characteristic of the pipe element selected from the group consisting of: diameter, wall thickness, and material of the pipe element, and combinations thereof.

11. The method according to claim 1, further comprising: include: A feed rate of the grooving roller for forming the grooves in the pipe element is selected based on at least one characteristic of the pipe element selected from the group consisting of: diameter, wall thickness, and material of the pipe element, and combinations thereof.

12. The method according to claim 1, It is characterized in that Determining the diameter of the groove includes: determining the number of revolutions of the grooving roller per revolution of the pipe element, including fractional parts thereof; The diameter of the groove is calculated using the number of revolutions of the grooving roller per one revolution of the pipe element, including the fractional portion thereof, and the diameter of the surface of the grooving roller.

13. The method according to claim 12, It is characterized in that Determining the number of revolutions of the grooving roller, including the fractional portion thereof, comprises counting the number of revolutions of the grooving roller, including the fractional portion thereof, for at least one revolution of the pipe element.

14. The method according to claim 13, further comprising: include: The at least one rotation of the pipe element is determined by sensing a feature on the pipe element a first time and a second time while rotating the pipe element.

15. The method according to claim 13, further comprising: include: The at least one rotation of the pipe element is determined by: marking the outer surface of the pipe element with a light reflecting surface that contrasts with the outer surface of the pipe element; shining light onto the outer surface of the pipe element; When the pipe element is rotated, first and second reflections of the light from the light reflecting surface are sensed.

16. The method according to claim 13, further comprising: include: The at least one rotation of the pipe element is determined by: positioning a magnet on the surface of the pipe element; When the pipe element is rotated, the first magnetic field and the second magnetic field are sensed.

17. The method according to claim 1, further comprising: include: Measuring a plurality of dimensions proximate the circumferential groove in the pipe element when the pipe element is rotated, measuring the plurality of dimensions comprises measuring at least one dimension selected from the group consisting of: a distance from an end of the groove to an end of the pipe, a width of the groove, a depth of the groove, a flattened height of the pipe, and combinations thereof.

18. A method of forming a circumferential groove in a pipe element having a longitudinal axis using a drive roller and a grooving roller having a known diameter, the method include: engaging a portion of an inner surface of the conduit element with the drive roller; engaging a portion of an outer surface of the pipe element with the grooving roller; forming the groove by rotating the pipe element about the longitudinal axis while forcing the grooved roller to advance a distance into the pipe element in discrete increments so as to displace material of the pipe element as a result of the rotation of the pipe element; while rotating the pipe element, measuring the circumference of the groove based on a number of revolutions of the grooving roller determined by sensing features marked on the outer surface; determining a diameter of the groove by using the circumference of the groove; comparing the diameter of the groove to a tolerance range for the diameter of the groove; Until the groove diameter is within the tolerance range: The forming, measuring, determining and comparing steps are repeated wherein the drive roller is rotated about a first axis, thereby rotating the pipe element about the longitudinal axis.

19. The method according to claim 18, further comprising: include: As the diameter approaches the tolerance range, the distance per the number of revolutions is reduced.

20. A method of forming a circumferential groove in a pipe element having a longitudinal axis and using a drive roller and a grooved roller, the method include: engaging the conduit element with the drive roller; engaging the grooved roller with the pipe element; forming the grooves by rotating the pipe element about the longitudinal axis while forcing the grooving rollers into the pipe element a discrete distance so as to displace material of the pipe element as a result of the rotation of the pipe element; calculating the number of revolutions of the pipe element required to form a groove of a desired diameter by using the distance of the discontinuity per revolution of the groove; counting the number of revolutions of the pipeline element; as well as When the number of revolutions required to form the groove of the desired diameter is reached, forcing the grooving rollers the distance into the discontinuity in the pipe element is stopped.

21. The method according to claim 20, further comprising: include: measuring the diameter of the groove; comparing the diameter of the slot to the desired diameter; The forming, calculating, counting and stopping steps are repeated.

22. A method of forming a circumferential groove in a pipe element having a longitudinal axis and using a drive roller and a grooved roller, the method include: engaging the conduit element with the drive roller; engaging the grooved roller with the pipe element; measuring a diameter of the pipe element while rotating the pipe element about the longitudinal axis; Calculating a desired groove depth tolerance corresponding to a desired groove diameter tolerance; forming the groove by rotating the pipe element about the longitudinal axis while forcing the grooved rollers against the pipe element so as to displace material of the pipe element; measuring the groove depth while rotating the pipe element; comparing the groove depth to the desired groove depth tolerance; as well as The steps of forming the groove, measuring the groove depth, and comparing the groove depth to the desired groove depth tolerance are repeated until the groove depth is within the desired groove depth tolerance.

23. A device for forming a circumferential groove in a pipe element having a longitudinal axis, the device include: a drive roller rotatable about a drive roller axis, the drive roller being engageable with an inner surface of the pipe element when the drive roller axis is oriented generally parallel to the longitudinal axis of the pipe element; a grooved roller rotatable about a grooved roller axis oriented generally parallel to the drive roller axis, the grooved roller having a known diameter, the grooved roller being movable toward and away from the drive roller to forcibly engage the outer surface of the pipe element to displace material of the pipe element and form the groove therein when the pipe element is rotated; a first sensor for determining an extent of rotation of the grooving roll and generating a first signal representative of the extent of rotation; a second sensor for determining an extent of rotation of the conduit element and generating a second signal representative of the extent of rotation; A control system is adapted to receive the first signal and the second signal, use the first signal and the second signal to determine a diameter of the groove, and control movement of the grooved roller toward and away from the drive roller in response to the diameter of the groove.

24. The device according to claim 23, It is characterized in that The first sensor includes a rotary encoder operatively associated with the grooving roller.

25. The device according to claim 23, It is characterized in that The second sensor comprises: a light reflecting surface adhered to an outer surface of the conduit element, the light reflecting surface contrasting with the outer surface of the conduit element; a light projector positioned to project light onto the outer surface of the duct element and the light reflecting surface adhered to the outer surface; A detector is adapted to detect light projected by said light projector when reflected from said light reflecting surface, said detector generating said signal representative of said projected light.

26. The device according to claim 25, It is characterized in that The light projector includes a laser.

27. The device according to claim 25, It is characterized in that The light reflecting surface is selected from the group consisting of: a specular reflecting surface, a diffuse reflecting surface, a contrasting color reflecting surface, and combinations thereof.

28. The device according to claim 23, It is characterized in that The second sensor comprises: a magnet adhered to a surface of the pipe element; A detector is adapted to detect a magnetic field, said detector generating said signal representative of said magnetic field.

29. The apparatus of claim 23, further comprising a third sensor for measuring a surface profile of at least a portion of the pipe element and generating a signal representative of the surface profile.

30. The device according to claim 29, It is characterized in that The third sensor comprises: a laser adapted to project a fan-shaped beam along at least said portion of said conduit element; a detector adapted to receive reflections of said fan-shaped light beam from said portion of said conduit element; A computer unit for converting the reflections into measurements representing the surface profile using triangulation, generating the signal representing the measurement, and transmitting the signal to the control system.

31. The device according to claim 23, It is characterized in that The grooving rolls are mounted on actuators that are controlled by the control system.

Images