US3525314A - Apparatus for coating the interiors of tubular members - Google Patents

Description

United States Patent lnventor Thomas R. Mc Clughan Houston, Texas Appl. No. 701,634

Filed Jan. 30, 1968 Patented Aug. 25, 1970 Assignee Schlumberger Technology Corporation New York, New York a corporation of Texas APPARATUS FOR COATING THE INTERIORS OF TUBULAR MEMBERS 17 Claims, 7 Drawing Figs.

US. Cl 118/317, 134/167 Int. Cl 1305b 13/06 Field ofSearch 118/214,

215, 754, 317, 318; 117/96; 15/59, 60, 66,101; 134/43, 152, 167. 168; 2l4/(Inquired); 117/18, 95; 118/306,622

[56] References Cited UNlTED STATES PATENTS 1,199,998 11/1916 Linderme 15/59 1,209,850 12/1916 Kintzele 15/60 2,084,093 6/1937 Kronquest 118/317X 2,227,734 1/1941 Meyer l34/l67X 2,927,044 3/1960 Gough 118/318X Primary Examiner- Daniel Blum Attorneys-Ernest R. Archambeau, Jr.. Richard E. Bee, Donald H. Fidler, David L. Moseley. Edward M. Roney and William R. Sherman ABSTRACT: The invention disclosed herein is directed to apparatus for coating the internal bores of vertically disposed elongated tubular members such as joints of pipe. More particularly, the apparatus disclosed herein includes a vertically movable coating applicator that is arranged to be selectively traversed through the internal bore of a vertically supported pipe. A guide member is arranged to cooperate with the coating applicator for reliably centering the pipe in relation to the applicator so that, as it is being operated, the coating applicator will pass easily through the pipe.

Patented Aug. 25, 1970 Sheet 1 of 3 7/20/7701 /P. M: C/uyfiaw INVENTOR.

147' 7 G g/V5 y Patented Aug. 25, 1970 3,525,314

Sheet 3 of 3 I N VENTOR.

ATTORNEY APPARATUS FOR COATING THE INTERIORS OF TUBULAR MEMBERS Where large numbers of elongated tubular members, such as joints of pipe and the like, are to be internally coated in a mass-production operation, various problems are presented. For example, an excessive amount of floor space is required if long joints of pipe and the like are transported in a generally horizontal position between the successive operations usually employed in typical coating procedures. On the other hand, if such pipe joints are transported in a generally vertical position, it has been necessary heretofore either to lay the pipes down into a predetermined horizontal position or else to rely upon elaborate switching arrangements and carefully arranged guides, stops, and the like to assure that the pipes are accurately aligned with the coating applicator as it is being operated.

Accordingly, it is an object of the present invention to provide apparatus for internally coating elongated tubular members in a vertical position, with this apparatus including means for accurately, but quickly, positioning the tubular members in succession as well as means for maintaining the coating applicator in alignment with each tubular member as it is being coated.

This and other objects of the present invention are attained by providing a selectively operable guide member that is cooperatively arranged with an elongated coating applicator, with the guide being adapted to engage the end of a tubular member to be coated and centralize the tubular member in relation to the coating applicator as it is passed through the tubular member.

The novel features of the present invention are set forth with particularity in the appended claims. The operation, together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is an isometric view of the apparatus of the present invention;

FIG. 2 is a more detailed view of a portion of the apparatus of the present invention;

FIG. 3 is a schematic representation of a typical installation of the apparatus shown in FIG. 1; and

FIGS. 4A-4D are successive views of the apparatus of the present invention as it will appear during a typical coating operation.

Turning now to FIG. 1, a somewhat simplified isometric view is shown of a coating apparatus arranged in accordance with the principles of the present invention and in readiness to coat the interior surfaces of an elongated tubular member such as a joint of pipe 11 suspended freely thereabove so that at least its lower end is capable of limited lateral movement. In general, the coating apparatus 10 is comprised of an elongated tubular lance 12 of a greater length than the pipe 11, with the lance being disposed in a generally vertical or erect position and supported at its lower end by a movable carriage 13 adapted for travel upwardly and downwardly along an upright guide, such as a pair of paralleled fixed rods 14 and 15, for a distance somewhat greater than the length of the pipe 11. To secure the rods 14 and 15, their lower ends are fixed to a base 16 and their upper ends are fixed to a cantilevered bracket 17 that is mounted on the upper ends of two upright frame members 18 and 19 carried on opposite sides of the base.

A coating applicator 20 is operatively arranged on the distal.

end of the lance 12 to uniformly distribute coating materials delivered thereto in a generally radial pattern as the lance is moved longitudinally through the internal bore of the pipe 11 that is suspended on a suitable overhead conveyor (not shown in FIG. 1) in substantially coincidental alignment with the central axis of the lance. As will subsequently be explained, flexible conduits 21 and 22 are respectively arranged to supply pressured air and coating materials by way of a distributor 23 on the carriage 13 and the lance 12 to the applicator 20 as it is traversed through the pipe ll.

It is, of course, desirable that the carriage 13 remain in substantial alignment with the pipe 11 as the applicator 20 is moved therethrough. Accordingly, as depicted in FIGS. 1 and 2, the lower end of the lance 12 is suitably secured, as at 24 and 25, to the distributor 23, with either a single or a pair of lateral support members on opposite sides of the carriage 13 being adapted for sliding travel along the fixed parallel rods 14 and 15. The outer ends 24 and 25 of the support member are preferably coupled to the rods 14 and 15 by suitable rod bearings 26 and 27, respectively mounted therearound, to allow the carriage 13 to move easily along the fixed guide rods.

To traverse the lance 12 upwardly and downwardly through the pipe 11, selectively-operable reciprocating driving means are provided such as a typical cable-piston actuator 28 that is secured in an upright position justabove the base 16. As is typical, the cable-piston actuator 28 is comprised of a tubular cylinder 29 having a free piston 30 slidably sealed therein and adapted for controlled movement in alternate directions in response to application of a pressured fluid to one end of the other of the piston. Cables 31 and 32 are respectively secured to opposite faces of the piston 30 and brought out of the cylinder 29 by way of suitable packing glands (only 33 seen) centered in the opposite ends of the piston cylinder. Once the cables 31 and 32 emerge from the cylinder 29, they are respectively directed over vertically aligned sheaves 34 and 35 that are suitably journalled at the opposite ends of the piston cylinder and appropriately sized to allow the cables to be vertically disposed a short distance in front of the cylinder where they are joined to one another so as to form a continuous loop. A connecting member 36 joins the carriage 13 to the cables 31 and 32 so that movement of the piston 30 in one direction along the cylinder 29 will carry the carriage 13 in the opposite direction. Thus, by selectively admitting a pressured fluid to the upper end of the cylinder 29 the piston 30 Willbe' moved downwardly to shift the lance 12 upwardly into the pipe 11. On the other hand, removal of this pressure or application of pressure to the lower end of the cylinder 29 will move the piston 30 upwardly and return the lance l2 and carriage 13 to their positions shown in FIG. 1.

To insure that the coating applicator 20 is accurately aligned with the pipe 11 before the lance 12 and carriage 13 are shifted upwardly, selectively-operable centralizing means 37 are provided with the coating apparatus 10. As shown in FIG. 1, the centralizing means 37 include a guide 38 that is adapted to contact the lower end of the suspended pipe 11 thereabove and shift the pipe as necessary to bring it into alignment with the coating applicator 20 as it is inserted into the pipe. Although it is preferred to arrange the guide 38 as an inverted, hollow frusto-conical member, it will be recognized that the guide needs only to be shaped so as to engage either the inside or outside of the pipe 11 and continue moving until i the pipe is contacting three circumferentially spaced points on the guide that have an equal radius from the central axis of the guide.

A reciprocating actuator 39, such as a piston cylinder 40 with a piston 41 operatively arranged therein, is fixed to the coating apparatus 10 and appropriately connected to the guide 38 so that the guide can be moved upwardly into contact with the lower end of the pipe 11 and shift the pipe into coaxial alignment with the coating applicator 21 before it has entered the pipe. So that the actuator 39 will not interfere with the travel of the carriage 13, it is preferred to mount the cylinder 40 along the front of the piston cylinder 29 just behind the cable 31 and connect the lower free end of the piston rod 42 to the inner end of a bifurcated transverse member or yoke 43 that has spaced arms 44 and 45 extending outwardly and straddling the cable 31 and lance 12. Rigid rods 46 and 47 are respectively secured to the outer ends of the arms 44 and 45 and extended vertically upwardly through the plate 17 where they are secured to a transverse base 48 on which the guide 38 is mounted. Where desired, suitable rod guides, as at 49 and 50 (FIG. 2), can, of course, be provided to prevent buckling of the rods 46 and 47. It will be appreciated that the arms 44 and 45 and rods 46 and 47 are appropriately spaced to allow the carriage 13 to move freely therebetween.

It will be noted in FIGS. 1 and 2 that the upper end of the lance 12 is extended through aligned apertures 51 and 52 in the fixed plate 17 and the movable base plate 48 so that the coating applicator 20 is normally coaxially disposed within the guide 38. Accordingly, once a pipe, as at 11, is suspended generally above the upper end of the guide 38 and coating applicator 20, upward travel of the inverted frusto-conical guide will cause at least the lower end of the pipe to be moved laterally into the center of the guide. Then, once the pipe 11 is centralized by the guide 38, the coating applicator 20 will be in alignment with at least the lower end of the pipe so that the applicator can freely enter the pipe. It will be realized, of course, that even should the guide 38 cause the pipe 11 to tilt slightly, the relative flexibility of the elongated lance 12 will allow the coating applicator 20 to still move easily along the internal pipe bore. Moreover, by forming the guide 38 as an inverted, hollow, frusto-conical member, the guide will be capable of accommodating many various sizes of pipes.

In any randomly selected lot of pipes, it will usually be found that the overall lengths of these pipes will vary somewhat. Thus, the stroke of the piston actuator 39 must be of sufficient length to be certain that the guide 38 will contact the lower ends of even the shortest ones of a number of randomly arranged pipes being coated. This will, of course, result in the guide 38 contacting the longer ones of these pipes before the piston 41 has reached its upper limit of travel. Thus, if the piston 41 was allowed to continue moving upwardly, a longer pipe could very likely be lifted by the guide 38 and, quite possibly, even be displaced from its support suspending it over the coating apparatus 10. Accordingly, as will subsequently be explained in greater detail, to prevent a long pipe from being lifted by the guide 38, the piston actuator 39 is appropriately governed so that it is unable to continue moving the piston 41 once the guide 38 contacts and centers the lower end of the suspended pipe.

The particular coating applicator 20 employed is, of course, incidental to the present invention. Thus, although the applicator could just as well be a typical spray nozzle, it is preferred to employ the applicator 20 as best seen in FIG. 2. As seen there, the coating applicator 20 is comprised of a suitable driver, such as an electrical or fluid-powered motor 53, having a rotatable annular coating distributor 54 mounted on the forward end of the shaft of the motor. To supply the motor 53 (which is preferably air-driven) as well as the coating distributor 54, the lance 12 is arranged as two concentric pipes 55 and 56 that are fluidly sealed from one another, with the longer inner pipe 55 preferably being used to conduct the coating materials and shorter outer pipe 56 carrying the pressured fluid such as air. If, on the other hand, the applicator 20 is electrically powered, the annular space 57 between the pipes 55 and 56 could be used to carry the necessary electrical conductors to the applicator motor.

Accordingly, the inner pipe 55 is fluidly connected to the distributor 23 on the carriage 13 and extended through the outer pipe 56 to a fluid manifold 58 carried on the forward ends of both pipes. To supply a pressured fluid to the applicator 20, the outer pipe 56 is also fluidly connected to the rear of the manifold 58 and extended back over the inner pipe 55 to a suitable branched fitting 59 that is arranged to receive a supply of pressured fluid from the flexible conduit 21 for passage through the annular space 57 between the pipes to the fluid motor 53. A rearwardly directed deflector 60 is mounted on the forward end of the air-driven motor 53 to deflect air being exhausted from its exhaust ports away from the centrifugal distributor 54.

To avoid conducting the coating materials through the shaft of the air-driven motor 53, one or more delivery tubes 61 are fluidly connected to the manifold 58, with these tubes being extended around the air-driven motor and appropriately arranged to supply coating materials to the centrifugal distributor 54. The forward end of the inner pipe 55 is in communication with an interconnecting longitudinal bore 62 formed in the manifold 58 and appropriately arranged to define a rearwardly-facing annular valve seat 63 therein. After emerging from the branched fitting 59, the rearward end of the inner pipe 55 is fluidly connected to a longitudinal bore 64 extending through the distributor 23 and intersected therein by a lateral bore 65 to which the flexible conduit 22 is fluidly connected. To regulate the flow of coating materials an elongated rod 66 has its forward end arranged as a valve member 67 that is complementally shaped for seating engagement with the valve seat 63. The elongated rod 66 is coaxially disposed for longitudinal movement within the inner pipe 47 and its rearward portion is extended to the exterior of the distributor 23 through suitable packing means 68 in the longitudinal bore 64. Although the elongated rod 66 could just as well be manually positioned, it is preferred to connect the rearward end of the rod to a selectively-operable reciprocating actuator 69 that is preferably actuated by a pressured fluid. Accordingly, it will be appreciated that the flow of coating materials through the lance 12 to the applicator 20 will be controlled by moving the valve member 67 into and out of seating engagement with the valve seat 63. Thus, once the actuator 69 is operated to shift the valve member 67 off of its seat 63, coating materials will be conducted to the centrifugal distributor 54 by the tubes 61.

Turning now to FIG. 3, the coating apparatus 10 of the present invention is schematically shown in an exemplary arrangement for successively coating a number of pipes 70-72 that are dependently suspended at spaced intervals along an overhead conveyor 73 for progressive movement over the coating apparatus 10 in the direction of the arrow 74. It will be assumed that the pipe 72 has already been coated and that the pipe 71 has just been moved into the depicted position just above the guide 38.

It will be appreciated that any one of a number of pneumatic, electrical, hydraulic, or electro-mechanical control arrangements can be devised to control the operation of the coating apparatus 10. The degree of sophistication of such a control system will, of course, be limited only by what may be considered to be justifiable for a given installation. Thus, since those with even ordinary skill in the art can readily devise numerous suitable control systems to serve their particular purposes, it is believed to be sufficient to describe only a fundamental control system so that the principles of the present invention can be better emphasized herein.

Accordingly, in one exemplary manner of controlling the operation of the coating apparatus 10, a source 75 of a pressured fluid, such as compressed air or a hydraulic fluid, is connected by suitable valve means, such as a multiple-port valve 76, that can be operated either manually or automatically to selectively direct the pressured fluid to either the upper end or the lower end of the piston cylinder 29 as required to control the travel of the carriage 13. For reasons that will subsequently become apparent, the guide actuator 39 is connected to the source 75 (or another source if desired) of pressured fluid by a pressure-limiting or regulating valve 77 that is adapted to maintain only a slight upward force on the guide 38. Although a cut-off valve can be employed, it is preferred, however, to always retain a slight pressure in the cylinder 40 as long as the source 75 is operatively connected to the valve 76.

To control the valve member 67 (FIG. 2), the valve actuator 69 is connected by a suitable control valve 78 to the pressure source 75 (or another source). The flexible conduit 21 is connected by a suitable control valve 79 to a source 80 of compressed air for driving the motor 53 as required. The conduit 22 is connected to a suitable source of coating materials such as may be provided by a pump 81 connected to a supply tank 82.

It will also be appreciated that, if desired, appropriate position-responsive means such as limit switches and the like can be arranged as required to halt a pipe, as at 71, at the proper position on the conveyor 73 to approximately center the pipe over the guide 38. Similarly, other limit switches and the like can also be arranged to regulate the extent of travel of the carriage 13 as well as to initiate or terminate the operation of the various elements of the coating apparatus as the lance 12 is advanced into and withdrawn from the pipe 71.

It is of particular significance to the present invention that the pressured fluid, such as compressed air, supplied to the piston actuator 39 is controlled by the pressure-regulating valve 77 which functions to limit the inlet pressure applied to the cylinder 40 to a level that is sufficient to elevate the guide 38 with a force that is so low that an opposing force somewhat less than the weight of the pipe 71 will halt the piston 41 and prevent further upward travel of the guide. Thus, although the upward travel of the guide 38 is effective to centralize the pipe 71, the guide cannot be moved upwardly any further than is required to center the pipe. Accordingly, by arranging the frusto-conical guide 38 to move freely only until it contacts a pipe suspended thereabove, various lengths and diameters of pipes can be readily accommodated without special precautions and adjustments. In this manner, the coating apparatus 10 is capable of successively coating a large number of randomly arranged pipes, such as at 70-72, having a wide range of diameters and/orlengths. It will be realized, therefore, that neither the particular sequence of operations of the coating apparatus 10 nor the control system employed to accomplish this sequence are critical to the invention. Instead, it is to be understood that the present invention requires only that a centralizer, such as at 38, is urged into contact with a pipe to be coated with only sufficient force to allow at least the lower end of the pipe to be moved laterally into alignment with the coating applicator before it enters the pipe. Then, once the pipe is centered, the centralizer 38 will be halted by the opposing weight of the pipe and maintain the pipe in alignment as it is being coated.

Turning now to FIGS. 4A-4D, a typical sequence of operations of the coating apparatus 10 is schematically illustrated. In FIG. 4A, the pipe 71 is assumed to have halted just above the guide 38 but may be in a slight misaligned position in relation to the axis of travel of the coating distributor 20. Accordingly, once the arrival of the pipe 71 in position above the coating apparatus 10 is sensed (either automatically or visually), the guide member 38 and coating applicator 20 are moved upwardly in unison until the guide contacts the lower end of the pipe as seen in FIG. 4B. It will be appreciated that even though the pipe 71 may have been swinging slightly, the flared end of the guide 38 will confine the lower end of the pipe and bring it to a halt as the pipe is centered.

Upward travel of the coating applicator 20 is, of course, obtained by applying a pressured fluid to the piston actuator 28. Thus, with the control system as shown in FIG. 3, the valve 76 is operated (either manually or automatically) to direct the pressured source 75 through the conduit 83 to theupper end of the cylinder 29 while any pressure in the lower end thereof is vented by the conduit 84 through an exhaust port 85 in the valve 76. The rate at which the pressure is applied will, of course, govern the speed of travel of the carriage 13.

It will be noted in FIG. 2 that the manifold 58 is sized to be somewhat larger than the opening 52 through the base plate 48. Thus, even though there is a pressure applied to the actuator 39 tending to lift the guide 38, so long as the carriage 13 is in the position shown in FIG. 4A, the lower end of the manifold 58 will be resting on the base 48 and will keep the guide in its retracted position. In this manner, as the carriage 13 is moved upwardly toward its position as shown in FIG. 4B, the pressure applied to the actuator 39 will simultaneously lift the guide 38 until it contacts the lower end of the pipe 71.

Once the guide 38 contacts the pipe 71, it can move further upwardly with only sufficient force to allow at least the lower end of the pipe to shift laterally as required to bring it into alignment with the applicator 20. Here again, it will be recalled that the motivating force moving the guide member 38 is sufficient only to centralize the lower end of the pipe 71 without also lifting the pipe. Thus, where a pressurized fluid (as at 75 in FIG. 3) is used to drive the guide 38, the pressure of this fluid is appropriately regulated to limit the motivating upward force acting on the guide to something less than the weight of the pipe 71. In any event, as seen in FIG. 48, once the lower end of the pipe 71 is centered, the guide 38 will be halted from further upward travel by the weight of the pipe and the coating applicator 20 will freely enter the lower end of the pipe as the carriage 13 is advanced further upwardly by the actuator 28.

It is of little or no consequence to the present invention as to whether the pipe 71 is coated on either one or both of the upward or downward traversals of the coating applicator 20 through the pipe. This choice of operating sequence will, of course, be one within the scope of one with only ordinary skill in the art. Thus, in FIG. 4C, the coating applicator 20 has passed through the pipe 71 and is now ready to be returned downwardly. To accomplish this, the carriage 13 is reversed and returned toward its original position. With a control system as shown in FIG. 3, the valve 76 will be actuated to supply pressured fluid through the conduit 84 and to connect the conduit 83 to the exhaust port 85. As seen in FIG. 4D, therefore, the coating applicator 20 is just emerging from the lower end of the pipe 71 as the carriage l3 nears its original position.

Although the control system can, of course, be arranged to positively return the guide 38 to its initial position, it is preferred to arrange the applicator 20 so that its return travel will restore the guide member to this initial position. Thus, as seen in FIG. 4D, and, in more detail, in FIG. 2, means such as the enlarged manifold 58 on the coating applicator 20, are provided to engage the upper face of the support plate 48 and return the guide 38 to its initial position as the applicator is moving back to its original position. Thus, although release or reduction of the actuating pressure in the cylinder 40 may be used to return the guide 38, it is preferred that the guide remain in contact with the lower end of the pipe 71 until it is disengaged therefrom by return of the coating applicator 20 to its initial position. The enlarged shoulder provided by the manifold 58 will, therefore, insure the positive retraction of the guide 38 to enable the pipe 71 to be transported away from the coating apparatus 10 and to allow the next pipe 70 to be moved into position.

Accordingly, it will be appreciated that the present invention has provided new and improved pipe-centering means for reliably centering a vertically-suspended pipe over a coating applicator. By arranging the guide as an inverted hollow conical or frusto-conical member, the guide member will contact at least three points on the lower end of a suspended pipe and shift it laterally into a desired vertical position in relation to the coating applicator. Moreover, by using an inverted hollow conical of frusto-conical guide, pipes of various diameters and lengths can be readily accommodated by the coating apparatus of the present invention. Furthermore, by urging the guide member into contact with the lower end of a vertically suspended pipe with only the minimum force sufficient to shift the pipe laterally into alignment, the apparatus of the present invention will be incapable of dislodging a suspended pipe from its support.

While a particular embodiment of the present invention has been shown and described, it is apparent that changes and modifications may be made without departing from this invention in its broader aspects; and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

Iclaim:

1. Apparatus adapted for coating the interior of a tubular member supported at its upper portion only so that it hangs freely in a generally vertical position and comprising:

applicator means including a coating distributor adapted for travel along a generally vertical axis and upwardly into a tubular member hanging freely thereabove in alignment with said vertical axis to distribute coating materials on the internal surfaces of that tubular member;

centralizing means adapted for travel upwardly along said vertical axis and into engagement with the lower end of that tubular member to move at least its lower end into general alignment with said vertical axis;

and actuating means connected to said centralizing means and selectively operable for urging said centralizing means into engagement with the lower end of that tubular member with a force less than the weight of that tubular member but sufficient to centralize that tubular member before said applicator means enters therein.

2. The apparatus of claim 1 further including:

means normally disabling said actuating means and responsive to movement of said applicator means toward that tubular member for enabling said actuating means to engage said centralizing means with the lower end of that tubular member.

3. The apparatus ofclaim 1 further including:

means responsive to movement of said applicator means downwardly out of the lower end of that tubular member for disabling said actuating means and disengaging said centralizing means from the lower end of that tubular member.

4. The apparatus of claim 1 further including:

means normally disabling said actuating means and responsive to upward movement of said applicator means toward that tubular member for enabling said actuating means to engage said centralizing means with the lower end of that tubular member and responsive to downward movement of said applicator means away from that tubular member for disabling said actuating means and disengaging said centralizing means from the lower end of that tubular member.

5. Apparatus adapted for coating the interior of a tubular member supported at its upper portion only so that it hangs freely in a generally vertical position above said apparatus and comprising:

applicator means adapted for upward and downward travel between vertically-spaced positions and including an upright elongated lance and a coating distributor on the upper end of said lance adapted for passage along a generally vertical axis through a tubular member supported vertically there-above in alignment with said vertical axis to selectively distribute coating materials along the internal surfaces of that tubular member;

a centralizer coaxially arranged around said lance and adapted for upward and downward movement relative thereto, said centralizer defining at least three contact surfaces lying in a common horizontal plane and circum ferentially spaced from one another about a circle around said vertical axis so that upward movement of said centralizer will bring said contact surfaces into engagement with the lower end of that tubular member and coaxially align at least the lower end thereof with said vertical axis;

and actuating means connected to said centralizer and selectively operable for moving said centralizer upwardly into engagement with that tubular member with a force less than the weight thereof to generally align at least the lower end of that tubular member with said vertical axis before said coating distributor moves upwardly thereinto from a lower position to a higher position.

6. The apparatus of claim 5 wherein each of said three contact surfaces respectively lie in an inclined plane intersecting said vertical axis at a common point of intersection.

7. The apparatus of claim 6 wherein said common point of intersection is below said horizontal plane.

8. The apparatus of claim 5 wherein said centralizer is a hollow frusto-conical member uniformly disposed about said vertical axis.

9. The apparatus of claim 8 wherein said frusto-conical member is inverted and sized so as to receive the lower end of that tubular member.

10. The apparatus of claim 5 further including:

means normally disabling said actuating means so long as said coating distributor is in its said lower position and responsive to upward movement of said coating distributor toward its said higher position for enabling said actuating means to move said centralizer upwardly into engagement with the lower end of that tubular member.

11. The apparatus ofclaim 5 further including:

means responsive to downward movement of said coating distributor out of the lower end of that tubular member for disabling said actuating means and returning said centralizer to a position below and out of contact with that tubular member as said coating distributor returns toward its said lower position.

12. The apparatus of claim 5 further including:

means normally disabling said actuating means so long as said coating distributor is in its said lower position and responsive to upward movement of said coating distributor toward its said higher position for enabling said actuating means to move said centralizer upwardly into engagement with the lower end of that tubular member and responsive to downward movement of said coating distributor out of the lower end of that tubular member for disabling said actuating means and returning said centralizer to a position below and out of contact with that tubular member as said coating distributor returns toward its said lower position.

13. The apparatus of claim 5 wherein said actuating means include:

a piston cylinder; a piston slidably disposed in said piston cylinder for movement therein in response to a pressured fluid; and pressure-developing means adapted to supply a pressured fluid to said piston cylinder at a pressure sufficient only to move said piston with a force less than the weight of that tubular member.

14. Apparatus adapted for coating the interior of a tubular member supported in a generally vertical position above said apparatus and comprising:

applicator means adapted for upward and downward travel between vertically-spaced positions and including an upright elongated lance and a coating distributor on the upper end of said lance adapted for passage along a generally vertical axis through a tubular member supported vertically there above in coaxial alignment with said vertical axis to selectively distribute coating materials along the internal surfaces of that tubular member;

a hollow frusto-conical centralizer coaxially arranged around said lance below said coating distributor and adapted for upward and downward movement relative thereto so that upward movement of said centralizer will bring said centralizer into engagement with the lower end of that tubular member and coaxially align at least the lower end thereof with said vertical axis;

a piston actuator connected to said centralizer and adapted to move said centralizer upwardly into engagement with that tubular member;

and means selectively operable for moving said centralizer into engagment with that tubular member to coaxially align at least the lower end thereof with said vertical axis before said coating distributor moves upwardly thereinto from a lower position to a higher position, said selectively-operable means including means for admitting a pressured fluid to said piston actuator at a pressure sufficient only to engage said centralizer with that tubular member with a force less than the weight thereof.

15. The apparatus of claim 14 wherein said fluid-admitting means are admitting a pressured fluid to said piston actuator before said coating distributor is moved from its said lower position and further including:

means on said applicator means adapted to restrain said centralizer from being moved into engagement with that tubular member so long as said coating distributor remains in its said lower position.

16. The apparatus of claim 15 wherein said restraining means include first and second abutting surfaces on said ap plicator means and said centralizer respectively adapted for abutment to hold said centralizer down so long as said coating distributor is in its said lower position.

returned downwardly toward its said lower position, re-engage said second abutting surface to disengage said centralizer from that tubular member and return said centralizer downwardly as said coating distributor reaches its said lower position.

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