CA1112413A - Fabrication of a flange adapter for plastic pipe - Google Patents
Fabrication of a flange adapter for plastic pipeInfo
- Publication number
- CA1112413A CA1112413A CA315,807A CA315807A CA1112413A CA 1112413 A CA1112413 A CA 1112413A CA 315807 A CA315807 A CA 315807A CA 1112413 A CA1112413 A CA 1112413A
- Authority
- CA
- Canada
- Prior art keywords
- section
- pipe
- plug
- ethylene
- assist
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Shaping Of Tube Ends By Bending Or Straightening (AREA)
Abstract
FABRICATION OF A FLANGE ADAPTER FOR PLASTIC PIPE Abstract of the Disclosure A method of forming a flange on a thermoplastic pipe wherein the end of the pipe is heated, the wall of the pipe is turned back on itself and the turned-back portion is turned outwardly to form a flange.
Description
4~3 .
FABRICATION O~ A FLAN OE ArAPTER FOR PLASTIC PIPE
-This invention relates to flaring the end of a thermoplastic pipe to form a flange.
Flanged connections for joining sections of plastic conduit have been proposed and utilized to a limited extent. In one method for provid-ing a flanged end on a plastic pipe, flanges are molded, then welded or fused to the end of the plastic pipe, as required. This method is gener-ally unsatisfactory because a variety of sizes of flanges must be main-tained in stock in order to have the required size when needed. This method is economically unsatisfactory because of the variety of molds re-quired to mold the various sizes of flanges. In another method, the end of a plastic pipe is flared with a heated flaring tool. This method is gener-ally unacceptable for flaring the end of a plastic pipe having a relatively thick wall. This method is also unacceptable because expansion of the pipe to the flange shape reduces the wall thickness of the expanded portion.
Accordingly, it is an object of this invention to provide a process for forming a radial flange on a plastic pipe.
Other objects and advantages of the i~vention will be apparent to one skilled in the art upon study of this disclosure and the appended draw-ing, of which:
FIGURES 1-6, inclusive, are views schematically illustrating vari-ous stages during the formation of a flange on a thermoplastic pipe.
In accordance with the present invention, there is provided a method of forming an annular flange on the end of a plastic pipe which comprises folding a first section of the end portion of a plastic pipe back upon the next succeeding section and compressing the turned-back section to form a flange.
The method of this invention is applicable to any size of plastic pipe. It is particularly applicable to large-diameter pipe having a rela-tively thick wall, i.e., pipe having an inside diameter of at least 6 inches and a wall thickness of at least ~ inch.
It is necessary tha~ the material in the end portion of the pipe have sufficient plasticity to allow the first section to be folded back on the next succeeding section. The required plasticity can be obtained by heating the pipe to a temperature substantially above ambient temperature.
Due to the relatively thick wall of large-diameter pipe, it is preferred that the pipe wall be heated on its inner and outer sides simultaneously.
This can be accomplished by heating at least a portion of the pipe in a heated oil bath or a heated glycol bath.
It is preferred that the material in the pipe have a mechanical memory, i~e., the material has a tendency to return to its original config-uration. This allows the first section of the end portion to be folded back on itself.
The polymer materials from which the pipes or pipe in sections are made are polymers of ethylene or copolymers of ethylene and a small quan-tity of a mono-l-olefin having 3 to 8 carbon atoms per lecule, i.e., up to about 10 weight percent~ Such polymers and copolymers have a weight average molecular weight in the approximate range of 200,000 to 1,000,000, preferably from 250,000 to 500,000~ It is presently preferred that the plastlc pipe be formed from a copolymer of ethylene and a mono-l-olefin, containing at least about 90 weight percent of ethylene. In a presently preferred embodiment, the plastic pipe is formed fron an ethylene/butene-l copolymer containing from 90 to 98 weight percent ethylene and from 2 to 10 weight percent butene-l~
Referring now to the drawing and particularly to FICURE l, the end portion 2 of a plastic pipe 4 is heated to a temperature substantially above ambient temperature. The axial extremity 6 of conduit 4 is positioned over a male plug 8 ha~ing a surface contour 10 adapted to fold the axial extrem-ity 6 and a first section 12 back upon the next succeedin~ section 14.
As shown in FIGURES 2-4, a force is applied to the pipe 4 moving it toward the plug 8 so that the first section 12 follows the contour 10 and folds back on the next succeeding section 14.
FABRICATION O~ A FLAN OE ArAPTER FOR PLASTIC PIPE
-This invention relates to flaring the end of a thermoplastic pipe to form a flange.
Flanged connections for joining sections of plastic conduit have been proposed and utilized to a limited extent. In one method for provid-ing a flanged end on a plastic pipe, flanges are molded, then welded or fused to the end of the plastic pipe, as required. This method is gener-ally unsatisfactory because a variety of sizes of flanges must be main-tained in stock in order to have the required size when needed. This method is economically unsatisfactory because of the variety of molds re-quired to mold the various sizes of flanges. In another method, the end of a plastic pipe is flared with a heated flaring tool. This method is gener-ally unacceptable for flaring the end of a plastic pipe having a relatively thick wall. This method is also unacceptable because expansion of the pipe to the flange shape reduces the wall thickness of the expanded portion.
Accordingly, it is an object of this invention to provide a process for forming a radial flange on a plastic pipe.
Other objects and advantages of the i~vention will be apparent to one skilled in the art upon study of this disclosure and the appended draw-ing, of which:
FIGURES 1-6, inclusive, are views schematically illustrating vari-ous stages during the formation of a flange on a thermoplastic pipe.
In accordance with the present invention, there is provided a method of forming an annular flange on the end of a plastic pipe which comprises folding a first section of the end portion of a plastic pipe back upon the next succeeding section and compressing the turned-back section to form a flange.
The method of this invention is applicable to any size of plastic pipe. It is particularly applicable to large-diameter pipe having a rela-tively thick wall, i.e., pipe having an inside diameter of at least 6 inches and a wall thickness of at least ~ inch.
It is necessary tha~ the material in the end portion of the pipe have sufficient plasticity to allow the first section to be folded back on the next succeeding section. The required plasticity can be obtained by heating the pipe to a temperature substantially above ambient temperature.
Due to the relatively thick wall of large-diameter pipe, it is preferred that the pipe wall be heated on its inner and outer sides simultaneously.
This can be accomplished by heating at least a portion of the pipe in a heated oil bath or a heated glycol bath.
It is preferred that the material in the pipe have a mechanical memory, i~e., the material has a tendency to return to its original config-uration. This allows the first section of the end portion to be folded back on itself.
The polymer materials from which the pipes or pipe in sections are made are polymers of ethylene or copolymers of ethylene and a small quan-tity of a mono-l-olefin having 3 to 8 carbon atoms per lecule, i.e., up to about 10 weight percent~ Such polymers and copolymers have a weight average molecular weight in the approximate range of 200,000 to 1,000,000, preferably from 250,000 to 500,000~ It is presently preferred that the plastlc pipe be formed from a copolymer of ethylene and a mono-l-olefin, containing at least about 90 weight percent of ethylene. In a presently preferred embodiment, the plastic pipe is formed fron an ethylene/butene-l copolymer containing from 90 to 98 weight percent ethylene and from 2 to 10 weight percent butene-l~
Referring now to the drawing and particularly to FICURE l, the end portion 2 of a plastic pipe 4 is heated to a temperature substantially above ambient temperature. The axial extremity 6 of conduit 4 is positioned over a male plug 8 ha~ing a surface contour 10 adapted to fold the axial extrem-ity 6 and a first section 12 back upon the next succeedin~ section 14.
As shown in FIGURES 2-4, a force is applied to the pipe 4 moving it toward the plug 8 so that the first section 12 follows the contour 10 and folds back on the next succeeding section 14.
-2--~;~12413 ,~ ~emale plllg assist 16 having a flat radial surface 18 is then positioned concentrically over the pipe 4 and placed in contact with the axial extremity 6. As shown in FIGURE 5, a force is applied to the plug assist 16, moving it toward the plug 8. As the plug assist 16 is moved toward the plug 8, the folded first section 12 is c~mpressed and generally follows the contour 10 of the plug 8~ The force applied to plug assist 16 is continued until the first section has assumed a radial flange configura-tion, as shown in FI~nR~ 6.
The thus-flanged pipe is maintained under pressure between the male plug 8 and the plug assist 16 until it cools sufficiently to hold its shape without reverting to its former shape~ The section can be cooled by water spray to accelerate such cooling.
The width of the flange, and concomitantly, the amount of first section 12 folded back on the next succeeding section 14, is dependent upon the pipe diameter and its wall thickness and the size of the bolt circle on the metal backup flange which is used to join two flanged pipes together~
Accordingly, flange size is a matter of preference. Similarly, the dimen-sions of contour 10 of the male plug 8 and the radial surface 18 of the female plug assist 16 are dependent upon the desired flange size.
While it is preferred that the male plug 8 be a single unit, it is within the scope of this invention to utilize a first mandrel, not shown, having a surface contour adapted to turn the first section back on the next succeeding section, and a second mandrel, not shown, having a surface con-tour ada~ted to turn the folded section radially outward.
The following example is given better to facilitate the understand-ing of this invention.
EXAMPLE
A 2~-inch section of pipe, having an inside diameter of 8 inches and a wall thickness of ~ inch, made of high density polyethylene was used.
This section was made from an ethylene/butene-l copolymer containing 95 weight percent ethylene and 5 weight percent butene-l, having a molecular
The thus-flanged pipe is maintained under pressure between the male plug 8 and the plug assist 16 until it cools sufficiently to hold its shape without reverting to its former shape~ The section can be cooled by water spray to accelerate such cooling.
The width of the flange, and concomitantly, the amount of first section 12 folded back on the next succeeding section 14, is dependent upon the pipe diameter and its wall thickness and the size of the bolt circle on the metal backup flange which is used to join two flanged pipes together~
Accordingly, flange size is a matter of preference. Similarly, the dimen-sions of contour 10 of the male plug 8 and the radial surface 18 of the female plug assist 16 are dependent upon the desired flange size.
While it is preferred that the male plug 8 be a single unit, it is within the scope of this invention to utilize a first mandrel, not shown, having a surface contour adapted to turn the first section back on the next succeeding section, and a second mandrel, not shown, having a surface con-tour ada~ted to turn the folded section radially outward.
The following example is given better to facilitate the understand-ing of this invention.
EXAMPLE
A 2~-inch section of pipe, having an inside diameter of 8 inches and a wall thickness of ~ inch, made of high density polyethylene was used.
This section was made from an ethylene/butene-l copolymer containing 95 weight percent ethylene and 5 weight percent butene-l, having a molecular
3-~ 12~13 weight of about 250,000, a density of 0.941 grams/cc and a high load melt index of 2 g/10 minutes (ASTM D-1238-70, Condition F); the resin contained 2 weight percent carbon black, 0~1 weight percent glycerine and 0.1 weight percent 4,4'-thio-bis~6-tert-butyl m-cresol).
About 6 inches of one end of the pipe section was heated in a bath of ethylene glycol at 275 F (135 C) until it was soft enough to be de-formed but not melted. It was then placed on a male plug and hydraulic pressure of about 2000 psi was applied until the pipe end had bent past 90 and generally conformed to the shape of the plug. On partial cooling, the end section folded back on itself.
A female mandrel assist was then placed o~er the pipe and hydraulic pressure at about 2000 psi was applied to form the flange and to maintain the flanged shape until the pipe had cooled sufficiently to maintain the shape.
Reasonable modifications are possible within the scope of this dis-closure without departing from the scope and spirit thereof
About 6 inches of one end of the pipe section was heated in a bath of ethylene glycol at 275 F (135 C) until it was soft enough to be de-formed but not melted. It was then placed on a male plug and hydraulic pressure of about 2000 psi was applied until the pipe end had bent past 90 and generally conformed to the shape of the plug. On partial cooling, the end section folded back on itself.
A female mandrel assist was then placed o~er the pipe and hydraulic pressure at about 2000 psi was applied to form the flange and to maintain the flanged shape until the pipe had cooled sufficiently to maintain the shape.
Reasonable modifications are possible within the scope of this dis-closure without departing from the scope and spirit thereof
Claims (6)
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE AS FOLLOWS:
1. A method of forming a flange on a plastic pipe having an end portion, a first section of said end portion and a next succeeding section of said end portion which comprises the steps of:
(a) raising the temperature of said first section of said end por-tion to a temperature substantially greater than ambient;
(b) turning back said first section upon said next succeeding sec-tion by positioning the axial extremity of said end portion over a male plug having a surface contour adapted to fold said axial extremity and said first section back upon said next succeeding section, and applying a force moving said pipe toward said plug so that said first section follows said contour of said plug and folds back upon said next succeeding section, thereby forming a first folded section;
(c) compressing said folded section by positioning a female plug assist having a flat radial surface concentrically over said pipe in con-tact with said axial extremity and applying a force, through said female assist, to said axial extremity, moving said female assist toward said male plug, whereby said folded section is compressed and follows said contour of said male plug, thereby forming a radial flange; and (d) allowing said pipe to cool while compressed between said male plug and said female plug assist.
(a) raising the temperature of said first section of said end por-tion to a temperature substantially greater than ambient;
(b) turning back said first section upon said next succeeding sec-tion by positioning the axial extremity of said end portion over a male plug having a surface contour adapted to fold said axial extremity and said first section back upon said next succeeding section, and applying a force moving said pipe toward said plug so that said first section follows said contour of said plug and folds back upon said next succeeding section, thereby forming a first folded section;
(c) compressing said folded section by positioning a female plug assist having a flat radial surface concentrically over said pipe in con-tact with said axial extremity and applying a force, through said female assist, to said axial extremity, moving said female assist toward said male plug, whereby said folded section is compressed and follows said contour of said male plug, thereby forming a radial flange; and (d) allowing said pipe to cool while compressed between said male plug and said female plug assist.
2. The method of claim 1 wherein said pipe has an inside diameter of at least 6 inches and a wall thickness of at least 1/2 inch.
3. The method of claim 1 wherein said pipe has a mechanical memory.
4. The method of claim 3 wherein said pipe is formed of a material selected from the group consisting of polymers of ethylene and copolymers of ethylene and at least one mono-1-olefin having from 3 to 8 carbon atoms.
5. The method of claim 4 wherein said pipe is formed from a copoly-mer of ethylene and butene-1 containing 95 weight percent ethylene and 5 weight percent butene-1.
6. The method of claim 1 wherein said first section is heated in a heated glycol bath.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA315,807A CA1112413A (en) | 1978-11-03 | 1978-11-03 | Fabrication of a flange adapter for plastic pipe |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA315,807A CA1112413A (en) | 1978-11-03 | 1978-11-03 | Fabrication of a flange adapter for plastic pipe |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1112413A true CA1112413A (en) | 1981-11-17 |
Family
ID=4112884
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA315,807A Expired CA1112413A (en) | 1978-11-03 | 1978-11-03 | Fabrication of a flange adapter for plastic pipe |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1112413A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4525319A (en) * | 1983-04-27 | 1985-06-25 | Prolite Plastics Limited | Method and apparatus for forming a single flange pipe adapter |
-
1978
- 1978-11-03 CA CA315,807A patent/CA1112413A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4525319A (en) * | 1983-04-27 | 1985-06-25 | Prolite Plastics Limited | Method and apparatus for forming a single flange pipe adapter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4156710A (en) | Fabrication of a flange adapter for plastic pipe | |
| US3719209A (en) | Arcuate tubular articles of rigid plastic | |
| US4984831A (en) | Pipe socket and a method of forming a pipe socket | |
| US3418409A (en) | Method for thickening the end of plastic pipe | |
| US5527503A (en) | Method for belling tubing ends without wall thinning | |
| US4177237A (en) | Method of molding socket of plastic resin tube | |
| US5833279A (en) | Crosslinked polyethylene tubing ends | |
| US6557907B2 (en) | Polyethylene connectors | |
| US6860524B1 (en) | Polyolefin connectors | |
| EP0563721B1 (en) | A method and apparatus for the orientation of a plastic pipe and an oriented ribbed plastic pipe | |
| WO1998006558A1 (en) | Improved boot and method of making such a boot | |
| CA1168821A (en) | Apparatus and method for forming ends on thermoplastic tubing | |
| WO1997047460A1 (en) | Heat-shrinkable uhmv polymer film, tubing, and roll covers | |
| WO1997047460A9 (en) | Heat-shrinkable uhmv polymer film, tubing, and roll covers | |
| US5554332A (en) | Process of manufacturing shaped elements from synthetic thermopolastics | |
| CA1112413A (en) | Fabrication of a flange adapter for plastic pipe | |
| US4345956A (en) | Method for making a pipe connection or fitting | |
| US3755528A (en) | Method for making tubular articles from a thermoplastic material | |
| US4521041A (en) | Pipe connection | |
| JP2000334818A (en) | Molding, blow molding machine for molding. and its molding method | |
| US6676886B2 (en) | Pipe belling process | |
| CN1142849C (en) | Device for forming stability regular cone nozzle on thermoplastic material pipe end with multi-stage | |
| JPS61273934A (en) | Preparation of ultra-high molecular weight polyolefine composite material | |
| EP0800911B1 (en) | Tool for automatically forming, on thermoplastic pipes, bellings of considerable longitudinal extension | |
| JPH06185681A (en) | Manufacture of corrugated pipe incorporating sleeve |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry | ||
| MKEX | Expiry |
Effective date: 19981117 |