Centrally threaded plug for heat exchanger tube and removal tool

Patent metadata

Field	Value
Publication number	US-9709346-B2
Application number	US-201414207979-A
Country	US
Kind code	B2
Filing date	Mar 13, 2014
Priority date	Mar 13, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A tube plug insertable in one end of a heat exchange tube, the tube plug formed as an shaft having a distal part and an opposite proximal part which terminates in a proximal end with an threaded hole extending axially in the proximal end in the distal direction, and a plug removal tool having a proximal handle part and a distal stem part which has external threads that match threads in the threaded hole in the plug's shaft, the stem part being threadedly insertable into the threaded hole in the proximal end of the tube plug, whereby rotation of the stem will urge the tube plug to rotate relative to the heat exchange tube and break free from being lodged in the bore thereof.

First claim

The invention claimed is:

1. A tube plug insertable into one end of a heat exchange tube, comprising:
a. a solid metal one-piece elongated shaft having length L, a distal part and an opposite proximal part which terminates in a proximal end with an elongated threaded hole extending axially into said proximal part in the distal direction to a depth D distance less than L, said shaft being tapered on its outer surface from said proximal end to said distal part such that said distal part has smaller diameter than said proximal part, with said outer surface having a fixed dimension at each axial location along the length of said solid shaft, and
b. a removal tool having (i) a handle part and a stem part extending in the distal direction which stem part has external threads that match threads in said threaded hole in said plug's shaft, said stem part being threadedly insertable in a first rotation direction a predetermined axial distance into said threaded hole in said proximal end of said tube plug, and (ii) a stop element situated on said stem part for barring further rotation in said first rotation direction of said stem part relative to said shaft after said stem part is threadedly inserted said predetermined distance into said threaded hole of said shaft,
c. where further rotation of said stem part in said first rotation direction will urge said tube plug to rotate in said first rotation direction relative to said heat exchange tube.

2. The tube plug according to claim 1 where said stop element comprises a flange extending radially outward of said stem part and located proximally of said threaded part of said stem for engaging said proximal end of said shaft.

3. A tube plug insertable into one end of a heat exchange tube, comprising:
a. solid metal elongated shaft having length L, a distal part and an opposite proximal part which terminates in a proximal end with a threaded hole extending axially into said proximal end in the distal direction to a depth D distance less than L, said shaft being tapered on its outer surface from said proximal end to said distal part such that said distal part has smaller diameter than said proximal part, and
b. a removal tool having (i) a handle part and a stem part extending in the distal direction which stem part has external threads that match threads in said threaded hole in said tube plug's shaft, said stem part being threadedly insertable in a first rotation direction a predetermined axial distance into said threaded hole in said proximal end of said tube plug, and (ii) a stop element situated on said removal tool stem part for barring further rotation in said first rotation direction of said stem part relative to said shaft after said stem part is threadedly inserted said predetermined distance into said threaded hole of said shaft, where said threaded hole is defined by threaded bore walls and a distal end wall, said stop element comprises a foot extending distally on said stem part for engaging the distal end wall of said thread hole,
c. where further rotation of said stem part in said first rotation direction will urge said tube plug to rotate in said first rotation direction relative to said heat exchange tube.

4. The tube plug according to claim 3 where said threads of said threaded hole are configured to allow insertion of said externally threaded stem a predetermined axial distance and to then bar further rotation of said stem relative to said shaft.

5. The tube plug according to claim 3 where said handle part has a proximal part extending transversely of said shaft.

6. The tube plug according to claim 5 where said proximal part of said handle part extends generally perpendicularly to said stem part.

7. A tube plug insertable into one end of a heat exchange tube, comprising:
a. a solid one-piece metal elongated shaft having length L, a distal part and an opposite proximal part which terminates in a proximal end with a threaded hole extending axially into said proximal end in the distal direction to a depth D distance less than L, said shaft being tapered on its outer surface from said proximal end to said distal part such that said distal part has smaller diameter than said proximal part, and
b. a removal tool having (i) a handle part and a stem part extending in the distal direction which has external threads that match threads in said threaded hole in said plug's shaft, said stem part being threadedly insertable in a first rotation direction a predetermined axial distance into said threaded hole in said proximal end of said tube plug, and (ii) a stop element situated on said removal tool stem part for barring further rotation in said first rotation direction of said stem part relative to said shaft after said stem part is threadedly inserted said predetermined distance into said threaded hole of said shaft,
c. where further rotation of said stem part in said first rotation direction will urge said tube plug to rotate in said first rotation direction relative to said heat exchange tube, where said threaded hole is defined by threaded bore walls and a distal end wall, said stop element comprises a foot extending distally on said stem part for engaging the distal end wall of said threaded hole, and
d. where said tube plug's threaded hole is threaded along its entire depth D, and said handle stem part is threaded from its distal end a length at least as long as said depth D.

8. The tube plug according to claim 1 for a heat exchange tube having a central bore of diameter D 1 , and where said tube plug has an outer diameter at said proximal end greater than D 1 , and an outer diameter at said distal end less than D 1 .

9. The tube plug according to claim 1 where said tube plug's shaft comprises solid steel.

10. The tube plug according to claim 1 where said shaft has a round cylindrical outer space, and said threaded hole extends centrally of said shaft.

11. A method for breaking the bond of a tube plug lodged in the bore of one end of a heat exchange tube where said tube plug is tapered on its outer surface from its proximal end to a smaller diameter distal end, comprising the steps:
a. forming a threaded hole in said proximal end of said tube plug, inserting in said threaded hole a mating threaded stem of a tube plug removal tool,
b. providing with said removal tool a stop element (i) to allow rotation of said threaded stem and axial traverse of said threaded stem in said threaded hole a maximum predetermined distance, and (ii) then to bar further rotation of said threaded stem of said removal tool relative to said tube plug, and
c. applying further rotative force to said removal tool to break said bond of said tube plug with said bore surface of said heat exchange tube.

12. A method according to claim 11 wherein barring further rotation of said stem comprises forming a shoulder on said stem intermediate the ends thereof to engage said proximal end of said tube plug.

13. A method according to claim 11 wherein barring further rotation of said stem comprises forming an axially extending foot at the distal end of said stem to engage the bottom wall of said threaded hole, thus blocking further rotation of said stem.

14. A method according to claim 11 wherein barring further rotation of said stem comprises forming threads in said threaded hole to have limited axial depth therein thus barring further rotation of said stem after it has reached said limited axial depth.

15. A method according to claim 11 further providing a handle extending radially outward from said stem, providing a lever for rotation of said stem.

Assignees

• Saudi Arabian Oil Co

Inventors

• Al-Otaibi Dhawi A

Classifications

• F16L55/13

  the closure device being a plug fixed by plastic deformation · CPC title

• Y10T29/49822

  by applying force · CPC title

• F28F11/02 Primary

  using obturating elements, e.g. washers, inserted and operated independently of each other (F28F11/06 takes precedence) · CPC title