JPH01118323A - Method and device for expanding sleeve and sealing it into peripheral pipe - Google Patents

Abstract

PURPOSE: To reduce a sealing cost for many tubes by inserting a tool device which respectively provides an expandable collet finger and an elastic expander into a tubular sleeve and expanding the finger and the expander. CONSTITUTION: A first long tool device 20 which joins many tubes 12 and sleeves 14 and a second tool device 120 which is connected to the end part are prepared. The first device 20 is provided with a cylinder assembly 28, into which plural fingers 31 expandable in the radial direction are inserted, and the second device 120 is provided with elastic expanders 136a, 136b which are compressed in the axial direction and expanding in the radial direction with a piston 126. A piston 34 and a tapered mandrel 36 are advanced to expand the collet 31 in the radial direction. Next, the expander of the tool device 120 is expanded to seal the tube 12 and the sleeve 14. Since sealing is executed via a fluid pressure, the sealing cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method and apparatus for inflating and sealing a tubular sleeve into a surrounding tube. More particularly, the present invention relates to the inflatable sealing of a tightly fitting metal sleeve into a surrounding tube and a dual pressurizable tool used to remotely achieve this sealing. Regarding equipment.

<Prior art> Air preheating used in steam power plants using fossil fuels as a heat source to preheat combustion air for tubes used in tubular heat exchangers, that is, high temperature flue gas. The vessel tubes develop leaks after several years of use due to metal corrosion, erosion, or fatigue and require repair or replacement. Leaks in these tubes usually occur near the tubesheet, but can occur anywhere along the tube. Replacing these heat exchanger tubes, especially for large heat exchangers containing 10,000 to 50,000 tubes, can be expensive, prolong plant downtime, and reduce dust pollution. Various methods and special tooling systems have been developed to repair these pipes quickly, inexpensively, and reliably in high-intensity environments.

Various methods and devices are known in the prior art for remotely expanding tubes into surrounding plates or tube sheets. For example, DeWald U.S. Pat. No. 2,319,216 discloses a pull-type tapered tube for expanding a heat exchange tube in a tubesheet using direct contact between a tapered wedge surface and the inner wall of the tube. An expander is disclosed.

U.S. Pat. No. 3,470,724 to Bretzb discloses a tube end forming apparatus that uses an external retaining collet to hold the tube end and a tapered center arbor pushed through the forming collet to expand the tube end. There is. U.S. Pat. No. 3,829,948 to Miller et al. discloses an apparatus for expanding tubes into a tubesheet using an expandable collet. U.S. Pat. No. 4,182,152 to Peil et al. discloses a grid sleeve expansion tool used to secure an inner guide tube to an outer sleeve and grid. U.S. Pat. No. 4,471,643 to Champeau et al. discloses a tool for drawing a tapered mandrel through a sleeve to butt and secure workpieces together. U.S. Pat. No. 4,068,372 to Atsushi Kamo et al. discloses a tube expander for retaining tubes in the tubesheet of a heat exchanger.

In this pipe expander, a rod inserted through a cylindrical elastic medium and a backup ring are used to expand the elastic medium by compressive force in the axial direction. U.S. Pat. No. 4,387,507 to Kelly et al. discloses a tube expander for expanding tubes for retention in a tubesheet using primary and secondary expander rings. Mueller, U.S. Pat. No. 4,418,457, discloses another device for expanding a tube into a bore in a tubesheet and controlling the expansion of the tube by the axial position of an elastomeric washer relative to the tubesheet. There is.

Also, in Kelly U.S. Pat. No. 4,567,631.

Another apparatus is disclosed for expanding tubes into a tubesheet using a plurality of axially compressively loaded elastomeric expansion rings.

These conventional techniques have various drawbacks, and there is no known method or self-contained device for remotely inflating a tubular sleeve that fits tightly into surrounding tubing to form a pressure-tight joint therebetween. It wasn't. Prior art techniques include conveniently quickly and strongly inflating a metal sleeve that fits tightly against the tubes in a tubesheet, so that it can withstand one cycle of use and be easily withdrawn from the inflated sleeve. A pressurizable tooling device is not shown. In accordance with the present invention, an improved elongated pressure-actuated tooling device is used to insert long, closely-fitting metal sleeves into the tube, and expand the distal ends of each sleeve radially against the inner wall of the tube. A pressure-sealing bone repair method has been developed.

The invention also includes inserting a tubular metal sleeve into the tube, sequentially inserting a tool into the sleeve, and expanding the sleeve radially to seal the sleeve in a pressure-tight manner with respect to the tube and tubesheet. Special pressurizable tools have also been developed to repair leaky pipes.

SUMMARY OF THE INVENTION The present invention provides a method for expanding opposing ends of a sleeve into a surrounding tube. The present invention specifically provides a method that utilizes a first elongated tooling device to remotely expand the forward end of a closely fitting sleeve into a surrounding tube. This method involves inserting a long, close-fitting tubular sleeve into the tube and extending it through any opening or break in the tube;
The long extension of the tool is then inserted into the sleeve and surrounding tube such that the collet fingers of the tool are located near the inner or forward end of the sleeve. The forward screw 1 of the tool is then pressurized to force a tapered mandrel secured to the forward end of the piston past the fingers of a radially expandable collet and against the inner ring of the sleeve. The fingers are expanded radially outward and the sleeve is expanded tightly against the inner wall of the tube to form an interference fit and seal therebetween. Further pressurization of the forward piston of the tool pushes the mandrel further through the fingers of the collet and retracts the fingers into contact with the small diameter portion of the mandrel before withdrawing the tool from the sealed sleeve and tube. The rear piston of the first tool assembly is then pressurized to retract the mandrel through the fingers of the collet to its initial position, resetting the tool in readiness for the next operating cycle of the tool assembly.

The present invention strongly expands the rear end of a closely fitting metal sleeve into a tube in a tube sheet such as a heat exchanger to form a pressure-tight interference fit between the outer surface of the sleeve and the inner surface of the tube. A method is also provided. According to this method, the forward end of the second tool is first inserted into a long metal sleeve located in the proximal end of the tube of the heat exchanger. After fully inserting the forward end of the tool, including the retaining nut, the elastic expander ring unit 1- and the forward part of the adapter flange of the housing into the sleeve, the forward port of the housing is pressurized.

Retracting the piston and axially compressing one elastic expander ring causes the rings to expand radially outwardly relative to the sleeve.

This expansion forces the rear end of the metal sleeve and the inner surface of the tube, which is already pressure-tightly sealed in the tubesheet, to expand radially outwardly. The joint formed by the tool is
Forming a rear pressure-tight seal between the damaged tube and the sleeve, which was previously pressure-tightly rolled into the bore of the tubesheet during the original manufacture of the heat exchanger.

After the elastic expander ring and sleeve are thus expanded against the tube, the front port of the housing is depressurized and the rear port is pressurized to move the retaining nut forward and relieve the axial pressure on the elastic ring. next,
The tool is withdrawn from the inflated sleeve and tube, inserted into another damaged tube, and the desired procedure repeated.

The present invention also provides a first elongated tool apparatus for internal sealing for remotely inflating a sleeve into a circumferential tube to form a pressure-tight seal therebetween.

A first tool arrangement for forward sealing comprises a housing and a long forward extension secured to a forward cylinder housing an axially movable piston pressurizable through a first port of the housing. There is.

The forward cylinder is secured to an expandable collet with radially movable fingers disposed at the forward end. A tapered mandrel fixed to the forward end of the piston is
axially forward by the forward piston so as to have a rear end of a large diameter and expand the fingers of the collet radially outward against the inner wall of the sleeve into which the collet is inserted; It is supposed to move.

The collet fingers push a localized portion of the sleeve radially outward until it contacts the tube, and then push the sleeve and tube together radially, creating a positive gap between the sleeve and tube. A locking and sealing joint is formed radially outwardly.

The mandrel has a reversely tapered small diameter section near its rear end so that as the mandrel advances further,
The small diameter trailing end allows the fingers of the collet to trail radially inward. This rear end of the collet finger makes it possible to withdraw the tooling device from the surrounding tube and tubular sleeve sealed against the sleeve.

The extension of the tool housing also includes a rear piston containing an axially movable piston, the rear piston being rigidly connected to the front piston by a central connecting rod and through a second port in the housing. Can be pressurized. Following withdrawal of the tooling device from the tube, pressurizing the rear piston in the tool housing moves the mandrel backwards through the fingers of the collet to its initial position, ready for repeated use. Reset the tool.

The present invention provides a sealable-pressurizable second tooling device or trailing end tooling device for use in effectively repairing leaking tubes of a heat exchanger.

This second tooling device is adapted to be inserted into a close-fitting sleeve disposed within the tubes in order to forcefully expand the ribs and tubes into the tube bores of the tubesheet of the heat exchanger.

The second tool device includes a housing having a longitudinal cylindrical shaft hole and a pressurizable front port connected to the shaft hole, and a housing closing plate having a rear pressurizable port. We are prepared. A housing adapter flange with a reduced diameter portion sized to fit over the tube end is located at the forward end of the housing to facilitate positioning of the tool relative to the sleeve and tubesheet. The cylindrical shaft bore of the housing contains therein an axially movable piston, the forward end of which is secured to a long rod to which an adjustable retaining nut is secured by screwing. An elastic expander unit having at least two elastic expander rings or washers (+ia) is provided surrounding the rod between the housing flange and the retaining nut. Preferably, each of the front and rear expander rings , the forward outer corner of the forward ring adjacent to the retaining nut and the housing flange, respectively, and the rearward one to minimize radially outward extrusion of each ring during repeated pressure cycles during use of the tool. The outer rear corner of the ring is chamfered.

The expander ring is comprised of a resilient extremer material that retains its elasticity through many high compression-decompression cycles during use of the tool. Useful ring materials include:
Included are polyurethanes, nylons, Teflon and synthetic rubbers, with polyurethane elastomers being particularly preferred due to their desirable high pressure properties.

The present invention also provides a method for effectively repairing corroded or broken pipes, thereby eliminating the need for costly and time-consuming reconfiguration or replacement of heat exchangers.

The present invention also provides a long duplex 1 for carrying out the sealing method.
A first tooling device is also provided, the first tool device being an elongated tool for being inserted into the closely fitting sleeve and tube of the heat exchanger to expand the sleeve into the tube and form a leak-tight seal therebetween. It is a tool device.

The second tooling device is inserted into a tightly fitting metal sleeve in the tube to expand the sleeve radially into the tubesheet to form a pressure-tight seal therebetween. This tooling device utilizes dual elastomeric expander rings, which are connected to a sealing ring unit to provide efficient radial expansion without undesired extrusion and provide long service life for the rings. The front and rear surfaces of each are each contoured to include chamfers at the outer corners. This effective pipe repair eliminates the need for expensive reconfiguration or replacement of air preheaters in fuel-based steam power plants.

<Example> As generally illustrated in FIG. 1, a vertical tubular heat exchanger 10 includes a plurality of tubes 12 whose lower ends are pre-expanded in a tube plate 13. The pipe 12 consists of a broken part 1
2a, and as shown in detail in FIG.
2 and locally inflating the sleeve 14 against the inner wall of the tube 12 so as to repair the break 12a by forming a pressure-tight expansion joint 15 at the distal end of each sleeve 14. Must be repaired.

This expansion joint 15 at the inner end of the tube 12 is formed by using a special first elongated tooling device 20 according to the invention. The lower end of sleeve 14 is later pressure-tightly sealed to the tube using another tooling device such as that described between pending US patents.

As shown in FIG. 2, the first elongated tool device 20 has a housing 22 with a reduced diameter, tubular elongated forward extension 23 for insertion into the sleeve 14; inserted into tube 12. The adapter 24 is
The outer space tube 26 is screwed to the front end of the front extension 23 by a threaded joint 23a.
A threaded portion 25 is screwed to the outer end of the adapter 24 .

Cylinder assembly 28 is screwed 27 to the forward end of spacer tube 26. Cylinder assembly 28
includes a collet 30, which is connected to the cylinder 2
A screw 29a is screwed to the front end of 9. colette 30
has at least three radially expandable fingers 3
1.

The forward end of each finger 31 of the collet 30 radially outwardly pushes an adjacent portion of the sleeve 14 so as to forcefully deform the sleeve 14 into the tube 12 to form a pressure-tight seal therebetween. On the other hand, there is a portion 31a expanded outwardly for contacting and pressing the tube 12.

The cylinder 29 has a circular tube hole 29b.
A piston 34 with a sealing ring 35 and a long front portion 34a is housed inside. The forward portion 34 of the piston 34 has an elongated mandrel 3 with an outer surface 36a.
6 is screwed 34b. The mandrel 36 is tapered rearward so that the rear end has a larger diameter. The tapered outer surface 36a is located adjacent to a reduced diameter portion 37 and a reverse tapered portion 37a at the rearward end of the mandrel 36. Tapered end portion 38 extends from sleeve 1 as shown generally in FIG.
4 and the forward end of the mandrel 36 is screwed 39 to facilitate insertion of the tooling device 20 into the tube 12.

The long inner spacer tube 40 also connects to the adapter 24.
and the cylinder assembly 28 and is pressure sealed to the adapter 24 by a sealing ring 41 and by a sealing cylinder 43 to the cylinder assembly 28.
8 is also sealed. The forward piston 34 is pressurized and advanced by fluid pressure applied to the sleeve expansion port 48 in the housing 22. The port 48 is connected to the piston 34 by a longitudinal annular passage 47 formed in the extension 23 of the housing 22 and a connecting annular passage 47a disposed between the inner spacer tube 40 and the connecting rod 46. has been done.

A second cylindrical bore 42 is formed in the distal end of the housing 22 of the tool device 20 in which an axially movable rear piston 44 containing a sealing ring 45 is accommodated. The rear piston 44 is secured by a central long connecting rod 46 that extends through the inner spacer tube 40 and is secured near the front piston 34 . The front surface of the rear piston 44 is pressurizable via a longitudinal passage 49 that is flow connected to a piston retraction port 50 in the housing 22 .

The rear part of the housing 22 is closed by a plug 52 secured by a threaded joint 53. If desired, reduced fluid pressure can also be applied to piston 44 at port 54.
The pressure applied to the piston 34 through the port 48 and passageway 47 may be increased and the mandrel 36 pushed forward through the fingers 31 of the collet 30. The relative positions of sleeve expansion port 48 and piston retraction port 50 are illustrated in FIG.

Front extension 23 of tool device 20 and cylinder assembly 2
8 is the small diameter necessary for easy insertion into a tight-fitting sleeve 14 in tube 12 and fitting 15.
The sleeve 14 has a length necessary to pressure-seal the inner end of the sleeve 14 to the tube 12 at the same time. The housing 22 of the tooling device 20 may have an outer diameter of 2 to 3 inches and an overall length of 4 to 8 feet. The tool typically has a length of about 1.8 m and its extension slides inside a close-fitting sleeve in a 1-2 inch (2.5-5.1 ann) diameter tube. It has a reduced outer diameter for a free fit. The taper of the mandrel 36 is such that the forward piston 34 limits the axial force required to force the fingers 31 of the collet 30 radially outward and force the sleeve 14 to expand into the tube 12. It is considered to be a relatively small value. The radial force required in the expanded portion 3La at the tip of the finger 31 is determined by the diameter, wall thickness and yield strength of the sleeve 14 and tube 12, and the deformation required to form a pressure-tight expansion joint 15. .

The coefficient of friction and the total radial force between outer surface 36a and finger 31 determines the axial force required to drive mandrel 26 forward from piston 34.

The amount of taper on the outer surface 36a is approximately 1 inch in diameter for a 1 inch length of the tapered mandrel 36.
．． It can range from 0.050 to 0.065 inches (3 to 1.7 m). The outer surface 36a of the mandrel 36 is typically coated with a low coefficient of friction material, such as molybdenum disulfide, thereby forming the tapered mandrel 36.
and the fingers 31 of the collet 30 are minimized.

The housing 22 has a sleeve 14 inside the tube 12.
The front end of the housing 22 is also provided with a shoulder 22a sized to fit over the tip of the housing 22.

A spacer piece 51 is also fixed. Tool device 20
During use, the forward end of the spacer piece 51 properly positions the expansion portion 31a of the finger 31 of the collet 3° relative to the inner end of the sleeve 14 to form the actual expansion joint 15. It is arranged in contact with the front surface 13a of the tube sheet 13 so as to make it easy to do so.

Tooling device 20 is typically made from high strength alloy steel;
Mandrel 36 is made of hardened high carbon tool steel.

The number of fingers 31 on collet 30 varies with the diameters of collet 30 and sleeve 14. For example, for a sleeve 14 with an outer diameter of approximately 3.6 mm (1.4 inches), six fingers 31 of collet 30 would be used and an outer diameter of approximately 7.4 mm (2.9 inches). In the case of sleeve 14, twelve fingers 31 of collet 30 are used.

Method steps for using the tool apparatus 20 of the present invention include:
The steps include pressing the elongated tubular sleeve 14 against the forward end of the tooling device 20 and then inserting the tooling device 20 and sleeve 14 into the tube 12 to be repaired (first, second
(see figure). Ports 4.8.50 of the tooling device 20 are connected to a hydraulic pressurization unit (not shown) by suitable high pressure hoses. A spacer ring 51 fixed to the front end of the housing 22 is abutted against the front surface 13a of the tube sheet 13. The shoulder 22a of the housing 22 is also used to push the sleeve 14 forward and properly axially position the sleeve 14 within the tube 12 to form an expansion joint 15 therebetween. .

After inserting the tooling device 20 into the sleeve 14 and properly positioning the sleeve 14 within the tube 12, the tooling device 20 is first inserted into the sleeve 245 at the sleeve inflation port 48.
~280kg/al (3500~4000psig
), the front piston 34 and the tapered mandrel 36 are advanced, and the fingers 31 of the collector l-30 are pressed radially outward against the sleeve 34 and the pipe 12. Tube 12 is further expanded radially outwardly to form a secure lock and joint 15 between sleeve 34 and tube 12 (FIG. 4).

As the mandrel 36 advances further through the fingers; 31 of the collet 30, the fingers 31 can automatically retract into the small diameter portion 37 of the mandrel 36, as shown in FIG. After pulling the tooling device 20 out of the inflated sleeve 14 and tube 12, the
Pressurize port 50 with pressure fluid under a pressure of 3500-4500 psig (3500-4500 psig) and pressurize rear piston 4.
The tool assembly 20 is reloaded by moving the tool 4 rearwardly, thereby drawing the tapered mandrel 36 from the fingers 31 of the collet 30 to the cutting position shown in FIG.

As shown in FIG. 6, a vertical tubular heat exchanger 1
10 comprises a plurality of tubes 112 whose lower ends are tightly expanded into a lower tube sheet 113. The break 112a in the tube 112 consisting of the tube 112, as shown in particular detail in FIG.
A sleeve 114 is inserted into each damaged tube 112 to form a pressure-tight seal at the lower end of the tube sheet 1.
13 must be repaired by locally inflating the outer surface of sleeve 114 to the inner wall of tube 112. This repair of the tube 112 is accomplished according to the invention by inserting a special tooling device 120 into the sleeve 114 and repairing the tube 11.
This is done by radially expanding sleeve 114 into contact with 2.

As shown in FIG. 7, pressurizable tooling device 120 includes a housing 122 with a longitudinal cylindrical axial bore 123 and a pressurizable forward port 124 connected to the axial bore. Piston 12 built into housing 122
6 is axially movable in the shaft hole 123 and is provided with an outer sealing ring 125. The rear end of the housing 122 is closed by a head plate 128, and the front portion 128a of the umbilical cord plate 128 is connected to the shaft hole 12.
3, is fixed to the housing 122 by a plurality of bolts 128b, and is pressure-sealed to the shaft hole 123 of the housing 122 by an outer sealing ring 127. A head plate 128 surrounds a rear extension 126a of the piston 126.

Pressurizable rear port 138 pressure sealed by inner sealing ring 129 and fluidly coupled to axial bore 123
It is equipped with

The front end of the piston 126 is screwed to a long rod 130t 126b, and this rod is attached to the ○ ring 13.
1 is pressure sealed to the housing 122.

The forward portion 130d of the rod 130 is of small diameter and extends through an adapter flange 132 that is removably secured to the front surface of the housing 122 by a plurality of screws 133. The adapter flange 132 has a small diameter forward portion 132a sized to fit into the tube 112 and into which a tightly fitting sleeve 114 is expanded. Contact with the aft end positions sleeve 114 axially relative to tube 112 and tubesheet 113. rod 130
A retaining nut 134 is screwed onto the forward end 130a of the retaining nut 134, which can be tapered to facilitate insertion of the nut 134 and tooling into the tube 112 and sleeve 114.

An expander unit 136 including two to four irregularly shaped elastic expander rings 136a, 136b, . . . is disposed between the front portion 132a of the adapter flange 132 and the nut 134. These rings are made of a resilient material that can withstand repeated high compressive loads without permanent deformation of the rings. Examples of useful elastic materials for the expander rings 136a, 136b... include polyurethane, nylon, Teflon, and synthetic rubber, among others.

Polyurethane elastomers are most preferred due to their favorable elastic properties and ability to withstand numerous cycles of use without permanent deformation. Polyurethane elastomers have the desirable property of being substantially solid under normal unpressurized conditions and exhibiting properties similar to pressurized fluids when strongly pressurized. Polyurethane disstomers also have the property of essentially returning to their original shape after strong compressive pressure is removed (memory properties).

A preferred suitable material is polyurethane elastomer XPE-, commercially available from Polaroid Corporation.
It is 10.

The expander unit 136 includes two annular washers or annular rings 136a, preferably of equal thickness.
, 136b. A chamfer 137 is formed on the front outer corner of the edge of the front ring 136a and the rear outer corner of the edge of the rear ring 136b.
This retards or prevents permanent swelling of rings 136a, 136b in situ due to the high compression and repeated axial loading required on 36b. Chamfer 1
37 is 30 to the surface of rings 136a, 136b.
ring 1 with an angle of ~60°, as shown in Figure 9.
36a, 136b have a radial dimension ±7 equal to 20-30% of the radius.

The front extension part of this tool device 2o is connected to the tube 1 in the tube plate 13.
It has a slightly smaller diameter than the sleeve 114 so that it can be easily inserted into the rear end of the sleeve 114 disposed in the sleeve 2. The length of the extended portion of the tool device 20 is sufficient to extend past the thickness of the tube sheet 13 and position the expander unit 136 within the thickness of the tube sheet 13. The outer diameter of the expander ring is
It is typically 1-2 inches and fits snugly into sleeve 114 of tube 112. The forward portion of the tool assembly 20 is typically 15-30 anns (6-12 inches) depending on the thickness of the tubesheet 13. Tool arrangement 20 is suitably made of high strength alloy steel.

A method of using a second tool arrangement to expand a close-fitting metal sleeve 114 into a tube 12 in a tubesheet 13 to form a pressure-tight interference fit therebetween. As shown, tubes 112 in tubesheet 113
First, the front end portion of the tool device is inserted into the sleeve 114 disposed in the sleeve 114.

The front face of adapter flange 132 typically
The extension portion 132a of the adapter flange 132 is typically disposed substantially aligned with the front surface of the tubesheet 113.

The tool is connected to a hydraulic fluid pressure unit (not shown) by a suitable hose. The forward port 124 of the housing 122 is then connected to a
psig), and the piston 126 is thereby retracted to axially compress the resilient expander unit 136, thereby diametrically forcing the sleeve 114 into the tube 112 in a pressure-tight manner, as shown in FIG. Inflate.

After expanding the sleeve 114, the tool housing 12
2, the front port 124 of the expander unit 124 is depressurized and the rear port 138 is pressurized to advance the piston 126 and the retaining nut 134 and release the axial load pressure on the expander unit 136. The tooling device 120 can now be easily withdrawn from the tube 112 and inserted into another tube 112 for the next cycle of use for expansion of the sleeve 114 into the tube 112. It has been found that the front ring 136a initially loses its elasticity due to its loading and relatively large compression and deformation and is replaced after 20 to 30 cycles of use.

After the next 20-30 use cycles, the retaining ring 1
Both expander rings 136a, 136b are replaced with new ones by removing 34.

SUMMARY OF THE INVENTION A first tool device for sleeve-tube expansion according to the present invention is constructed and used for pressure-tightly sealing the inner end of a sleeve into a tube of an air preheater of a power plant. . Heat exchange
The tooling device has the following typical dimensions and characteristics:

Inner diameter of tube 12 4.6 mark (1,
834 inches) length of sleeve 14
198 cm (78 inches) outer diameter of sleeve 14
4.6 ■ (1,800 inches) Inner diameter of sleeve 14 4.10 (1,634 inches) Tooling! Length of 20: 210cm (83 inches) Outer diameter of housing 22 of tool device 20: 6.4cm
+n (2,5 inches) diameter of forward piston
3.3 (1) (1,31 inches) Rear piston diameter 1.4 ■ (0,56 inches) Number of fingers 31 on collet 30 10 Pressure on front piston 34 280 kg/al (4000 ps
i g) Pressure on rear piston 44 280
kg/a (4000 psig), the rear end of the forward extension of the tool is first inserted into the long metal sleeve placed in the tube of the heat exchanger, and the tool is moved forward against the tube. the collet fingers of the tool near the forward or inner end of the sleeve.The forward piston of the tool is pressurized by a hydraulic fluid pressurization unit connected to the tool arrangement, and the tapered mandrel is Pushed forward, the collet fingers are expanded and the sleeve is
Expanded strongly against the tube, the tube and sleeve are expanded radially together to form a positive lock and seal between the sleeve and tube. This pressurization and sleeve sealing process takes 10 to 15 seconds. The tool arrangement is then withdrawn from the sleeve and tube, the pressure unit pressurizes the port on the rear piston of the tool, and the mandrel is withdrawn through the collet fingers, resetting the tool and preparing it for the next cycle of use. do. This procedure is repeated for each tube in the heat exchanger that is repaired using the method of the present invention.

A second sleeve-tube expansion tool device in accordance with the present invention is constructed and used to expand and tightly seal the rearward end of the sleeve into a tube in a tubesheet of a heat exchanger. Tooling equipment and heat exchangers have the following typical dimensions and characteristics:

Inner diameter of tube 4.6an (1,8
34 inches) Sleeve outer diameter 4.6■
(1,800 inches) inner diameter of sleeve
4.1 mark (1,634 inches) tool length
20G (8 inch) Outside diameter of tool device housing 10.1 AN (4 inch) Diameter of screw 1 hem 8.3 AN (3.25 inch) Outside diameter of expander ring 4.1 ■ (1,625 inch) Piston diameter Working pressure 140kg/aJ
(2000 psig) In use, the forward extension of the tooling device is inserted into a metal sleeve disposed in the tube of the heat exchanger to laterally align the expander ring in the tubesheet of the heat exchanger. The forward port of the tool can be controlled at 140 kg/cot by means of a suitable hydraulic pressurization unit connected to the tool.
gauge pressure) (2000 psig), thereby driving the piston rearward and expanding expander rings 136a, 136b, causing tubesheet 1 in tubesheet 113 to
The metal sleeve 114 is inserted radially outwardly relative to the metal sleeve 12 . Next, depressurize the front port of the tooling housing,
Approximately 140 kg/d (gauge pressure) at rear port 138
A vacuum (2000 psig) is applied to advance the pistons, relieving the axial force on the expander rings 136a, 136b and allowing the tooling to be withdrawn from the sleeve 114 and tube 112. This procedure is repeated for each tube to be repaired using the method of the invention.

Having described that particular embodiment of the invention above,
Since the present invention can be implemented in various modifications other than the embodiments described above, the specific configurations described above are merely illustrative and do not limit the present invention.

[Brief explanation of the drawing]

FIG. 1 shows a section of a heat exchanger containing a plurality of tubes and a first pressurizable tooling device used to inflate a sleeve into a leaking tube of the heat exchanger. FIG. 1A is a partial side view, FIG. 1A is a partial cross-sectional view showing the sleeve expanded into the heat exchange tube and tubesheet to form a sealing joint for the tube; FIG. Figure 3 is a longitudinal cross-sectional view of the elongated tooling device inserted into the sleeve in the tube, with the mandrel and collet fingers shown in their initial normal unexpanded position relative to the sleeve;
FIG. 4 is a partial cross-sectional view of the tool assembly after pressurization, with the collet fingers shown in an unexpanded position in the sleeve and tube. FIG. 5 is a partial cross-sectional view of the tooling device, with the mandrel moved to a forward position and the fingers of the collet retracted so that the tooling device can be withdrawn from the sleeve and tube; FIG. 6 is a partial side view showing a portion of the heat exchanger housing a plurality of tubes and a second tooling device used to inflate the sleeves onto the tubes in the tubesheet of the heat exchanger; Figure 6A is a partial cross-sectional view of the sleeve after being expanded into the tubesheet and tubes of the heat exchanger; Figure 7 is a longitudinal cross-sectional view showing the sleeve in the tubesheet and the tool inserted into the tubes; and FIG. 8 is a partial longitudinal section showing the tooling and tube with the expander ring and sleeve in the expanded position in the tube. Figure, Figure 9 is. FIG. 3 is a partial cross-sectional view showing the expander unit and rod of the tool device. 12...Pipe, 14...Sleeve, 20...First tool device, 30...Collet, 31...Finger, 13b...
Elastic expander unit. Representative Patent Attorney Naoma Sakai Kane Saka - Shigeru Kane Saka FIG, /FIG, /AFIG
6 FIG8 FIG9

Claims (1)

Claims: 1) A method of remotely inflating and sealing a tubular sleeve into a surrounding tightly fitting tube using a dual elongated pressurizable tooling apparatus comprising: (a) a tube; inserting an elongate tubular sleeve having a length extending through any break into the tube; (b) inserting a first elongate pressurizable tool device into the sleeve to remove the forward end of the sleeve; the front of the sleeve by aligning the fingers of a radially expandable collet of the tooling in the vicinity and then applying pressure to the tooling to expand the fingers outwardly against the inner surface of the sleeve. expanding the end toward the wall of the tube to form a seal therebetween, and then withdrawing the first tooling device from the sleeve and tube; (c) a housing containing an axially movable piston; inserting a pressurizable second tooling device into the sleeve, the second tooling device having a resilient expander unit disposed near the rearward end of the sleeve; (d) pressurizing the second tooling device to cause its piston to move; retracting and radially compressing the elastic expander unit;
expanding the rearward end of the sleeve radially toward the wall of the tube, forming a seal therebetween; (e) withdrawing the second tooling device from the sleeve and surrounding tube; Sealing method. 2) a method of remotely expanding the forward end of a tubular sleeve into a surrounding tube to form a sealed joint therebetween using an elongated expander tooling device, comprising: (a) inserting the elongated tubular sleeve into the tube; (b) inserting an elongate tooling device into the sleeve and aligning a radially expandable finger of a collet of the tooling device near the forward end of the sleeve; (c) a forward piston of the tooling device; applying pressure to force an axially movable tapered mandrel secured to the forward end of the forward piston through expandable fingers of the collet to expand the fingers outwardly toward the inner surface of the sleeve. (d) further pressurizes the forward piston to further push the mandrel through the collet fingers, thereby retracting the collet fingers; (e) withdrawing the tooling device from the inflated sleeve and tube; (f) pressurizing the rear piston of the tooling device to retract the mandrel through the fingers of the collet and resetting the tooling device for next use; Formation method consisting of setting. 3) an elongate first tool device for remotely inflating a forward end of a tubular sleeve into a surrounding tube, the first elongate tooling device comprising: (a) a first port and a second port, the forward extension being secured to the forward cylinder; (b) a collet secured at a forward end to the forward cylinder and having at least three radially expandable fingers disposed at the forward end of the collet; (c) in the forward cylinder; an axially movable forward piston connected to a long tapered mandrel having a large diameter aft end and a longitudinally extending smaller diameter adjacent portion; (d) the mandrel is axially slidable within the collet and connected to the forward guide portion; and (d) the mandrel is disposed within the housing and receives the rear piston. a rear cylinder, the rear piston being rigidly connected to the rear piston by a centrally disposed rod extending therebetween; an elongated tube, the tube being arranged to provide fluid pressure from a port in the first housing to an aft end of the forward piston, the first port flow of the housing to an aft end of the forward piston; and a second port flow is connected to the forward end of the rear piston such that the forward extension of the tooling
insertable into a tubular sleeve, the forward piston comprising:
Pressure was applied to advance the tapered mandrel to expand the fingers of the collet radially toward the sleeve, thereby expanding the sleeve into the tube and sealing the sleeve into the tube. First tool device. 4) an elongated first tooling device adapted to remotely inflate a forward end of a tubular sleeve into a surrounding tube to form a seal therebetween, the forward end being secured to a forward cylinder; a housing having a spacer and a forward extension and defining a first port and a second port; (b) a forward end secured to the forward cylinder;
a collet having ~12 radially expandable fingers disposed at the forward end; (c) a forward piston movable axially in the forward cylinder, the forward piston having an elongated taper; connected to a tapered mandrel, the tapered mandrel comprising:
the mandrel has a large diameter aft end and a longitudinally extending adjoining portion of a small diameter, the mandrel being axially slidable within the collet and having a forward taper of a slightly smaller diameter than the collet; (d) having a rear cylinder disposed within the housing and housing a rear piston, the rear piston being connected to a centrally disposed rod extending therebetween; (e) a long tube centrally disposed about the rod, the tube extending from a port in the first housing to an aft end of the forward piston; the first port flow of the housing is arranged to provide fluid pressure, the first port flow of the housing being connected to the aft end of the forward piston, and the second port flow being connected to the forward end of the aft piston; The forward extension of the tooling device is insertable into the tubular sleeve, and the forward piston is pressurized to advance the tapered mandrel by expanding the collet fingers radially toward the sleeve. A first tooling device adapted to inflate the sleeve into the tube and seal the sleeve into the tube. 5) A method for radially expanding the rearward end of the sleeve into a surrounding tube in the tubesheet, comprising: a housing containing an axially movable piston; and a resilient expander unit disposed at the forward end of the housing. inserting a tooling device into a tightly fitting sleeve to be expanded in a surrounding tube, pressurizing the tooling device to retract the piston and axially compress the expander unit; forcefully expanding the unit and sleeve radially toward the inner wall of the tube to form a pressure-tight seal therebetween; and compressing the expander unit by releasing axial compression from the expander unit. A method of expansion comprising pressurizing a tooling device to move the piston forward and withdrawing the tooling device from the tubes in the tubesheet and the expanded sleeve. 6) A pressurizable tool adapted to inflate the rearward end of the sleeve into the surrounding tube in the tubesheet, the tool having a cylindrical axial bore and a forward port connected to the axial bore. a housing; a shutoff plate having a forward portion inserted into the axial bore and a rear port connected to the axial bore; and axially movable within the axial bore of the housing;
a piston having a forward end secured to an elongated rod, the rod including a retaining nut screwed to the forward end and further surrounding the rod between the housing and the retaining nut. The elastomeric expander unit includes a plurality of elastomer rings and has chamfers on the outer edges of its front and rear surfaces so that when the front port of the housing is pressurized, the piston moves rearwardly in the housing to compress the elastomeric expander unit axially relative to the housing causing the expander unit to expand strongly radially relative to the sleeve into the tubes in the tubesheet. A tool that can be pressurized. 7) A pressurizable tool adapted to inflate the rear end of the sleeve into the surrounding tube in the tubesheet, the tool having a cylindrical axial bore and a forward port connected to the axial bore. a housing; a shutoff plate having a front portion inserted into the axial bore and a rear port connected to the axial bore; and a piston movable axially in the axial bore of the housing; A rearward extension of the piston extends through the shut-off plate and has a forward end secured to a long rod with a retaining nut screwed to the forward end of the rod, and a retaining nut screwed to the forward end of the rod. an adapter flange rigidly attached to the forward end of the housing, the adapter flange including a forward shoulder sized to fit inside the tube and contact the rearward end of the sleeve; a dual expander unit surrounding the rod between the adapter flange and the retaining nut, the expander unit including dual rings each having a chamfer disposed on an outer edge of a front surface and a rear surface; Pressurizing the forward port of the housing causes the piston to move rearwardly within the housing, compressing the elastomer expander unit axially against the adapter flange of the housing and forcing the expander unit into the tube in the tubesheet. A tool configured to expand strongly in the radial direction with respect to the sleeve.