CA2182763A1

CA2182763A1 - Pipe section especially for use in pipelines carrying abrasive or corrosive materials

Info

Publication number: CA2182763A1
Application number: CA002182763A
Authority: CA
Inventors: Giulio Grossi
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-08-06
Filing date: 1996-08-06
Publication date: 1998-02-07

Abstract

A pipe section, which may be a length of pipe or may be a pipe fitting such as an elbow or a junction, and which is suitable for connection to other pipe sections to make a pipeline especially a large diameter pipeline used for carrying abrasive or corrosive materials. The pipe section comprises several longitudinal portions connected by longitudinal joints, each joint including a pair of longitudinal flanges extending along, and projecting radially from, edges of adjacent longitudinal portions, the flanges being connected together by a series of fasteners such as bolts which normally hold the flanges together in sealed relationship. The fasteners are removable to allow replacement of one of the longitudinal portions while others of the portions remain in place in the pipeline, thus reducing considerably the cost of repairing a large pipeline.
The pipe fittings may be elbows, tees or wye fittings, and these may be split longitudinally along a central plane of symmetry.

Description

~ 21~2763 PIPE SECTION ESPECIALLY FOR USE IN PIPELINES CARRYIN(3 ABRASIVE OR CORROSIVE MATERIALS

BACKGROUND OF THE INVENTION

1. Fi~ of th~ Tny- -~

5 The present invention relates to pipe sections used to make up pipelines for carryingabrasive or corrosive materials. Such pipelines are used in the mining and cement industries and elsewhere for carrying slurries or . - which cause .. :1 .i.l.l.
wear to standard steel pipes. The term "pipe section" includes not only straight lengths of pipe but also elbows and, , for example T or Y junction fittings, also 10 lcnown as tee or wye fittings.

2. Pri~ r Art of - T

Pipes for carrying abrasive or corrosive materials are usually made of steel, stainless steel, cast iron, ductile iron, or -' , and are often provided with a protective liner which may be of glass, cement, ceramic, rubber, or various kinds of 15 organic/inorgamic materials. In spite of such linings, sections of such pipelines, including c , are subject to d ~ over time and must be replaced. The pipe sections are expensive and replacing a section of a large pipe can cost around ~ ~18~763 $3,000. There is a need to reduce this cost.

SUMMARY OF THE INVENTION

The present invention provides a pipe section which comprises several l~-n- i' '' portions connected by ~ n~- ' ' joints. Each joint includes a pair of I n"
5 flanges extending along, and projecting radially from, the edges of adjacent porlions of the pipe section. These flanges are cormected together by a series of fasteners which normally hold the flanges together in sealed .~ ' ~, but which are removable to allow ,~ ~ ' of one of the I ~ ' ' portions while amother porlion or portions remains in place in the pipeline. This allows substantial savings, since it in many cases 10 only one side of a pipe section, affecting one of the portions, is subject to wear.

Normally, the pipe section is formed of two l~-ngih ' ' porlions, each porlion having a main curved body, for example a part-cylind~ical body, having one of the 1- n~i' ' ' flanges extending along each of its edges. Such a section can be repaired by removing the fasteners connecting the l~ l" ' ' flmges, as well as other 15 fasteners joining the ends of the pipe section to the upstream and ,lu..~ . sections of the pipeline. The fasteners are usually nuts amd bolts.

The pipe section may be in the form of a cylinder, each porlion forming one-half of the cylinder, the two flanges being coplanar.

~ 218~763 Also, the section may be the form of an elbow, and may comprise two portions which are identical but of opposite hand, the portions being joined at a central plane which is the plane of curvature of the elbow, and which is also the plane of symmetry.
Alternatively, the elbow may comprise a radially imner portion amd a radially outer 5 portion, which portions are connected by curved joints which are ~ d;~ulal to the plane of curvature of the elbow and which follow the curvature of a cent~al axis of the elbow.

F. i' ~, the pipe section may be in the form of a jumction fitting havmg a central plane of symmetry, the junction fitting being formed of two identical but opposite 10 hand portions, and tne joints being located at the plane of symmetry. Alternatively again, the l ~ ~ l portions may be inner and outer portions.

It will be evident that the pipe sections must also have means whereby their ends can be comnected to the ends of otrner sections to make up the pipeline. For this purpose, the pipe section may have circular end flamges which are split between the porrions of the section.

Normally, each l ~ ' ' portion of the pipe section has a liner capable of resisting abrasive or corrosive material, the liner being made of materials known for this pull)ose.

~ 21g2763 BRIEF DESCRIPTION OF THE DRAWINGS

The preferred ,: ' ' of the present invention will now be described in detail by way of example with reference to the ~ y ., drawings showing various kinds of pipe section in accordance with the invention, in which;

5 Figure la is a perspective view of a straight pipe section having flanged ends;

Figure lb is a similar view of an al'ternative form of pipe section, having grooved ends;

Figures 2a and 2b are pc~ liv~, views of tee fittings, lc;~lJc~Liv~ly having flanged and grooved ends;

0 Figures 3a and 3b are p~ L)~L~ view of 90 elbows, having lc~ liv~,ly flanged ends and grooved ends;

Figures 4a and 4b are perspective views of 22.5 elbows, having l~,ocL v~,ly flanged ends and grooved ends;

Figures 5a and Sb are perspective views of wye fittings, having lc~,~L~,ly flanged 15 ends and grooved ends;

2 7 6 ~

Figures 6a amd 6b are p~ c~ , views of alternate forms of 90 elbows, having J flanged amd grooved ends;

Figures 7a and 7b are p~ views of alternative forms of tee, having flanged and grooved ends; and 5 Figures 8 and 9 are perspective views of alternative forms of elbow and wy-e fitting ly, each having flamged ends.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, Figure la shows a straight pipe section 10 with end flanges 12 which are suitable for conmecting onto other similar sections or onto elbows or o junction fittings. The pipe section can have a diameter of from 4 to 24 inches, and the pipe may be made of stainless steel, black steel, cast iron, ductile iron, aluminium or other materials usual in this art. The pipe section has an intennal liner indicated at 14, which may be of various liner materials normally used in tbis art.

In accordance with the invention, the pipe section, including the liner 14, is formed of two identical 1~ n~ ' ' portions 10a and 10b connected by I n, ' ' joints extending along opposite sides of the section. Each portion comprises a semi-~.r" ' "~/ curved body along the outer edges of which are welded I ,i~ ' ' ~I 2~ g2763 flamges 16 which project radially from the edges of the portion and which are normally held together by fasteners in the form of nuts and bolts 18 ftted into aligned holes in the flanges. Gaskets of rubber or the like between the flanges ensure that the joint remains ~ , leak free, even when handling fluid at pressure. The end flanges 5 12 are split between the l ~ ' ' portions, with flange par~ 12a on one portion lOa and flange part 12b on the other portion lOb so that the whole section can be split in two along a central plane of symmetry when the bolts 18 are removed. To assist in correct assembly of the parts, alignment tabs 19 are provided at the ends of all the flanges.

o Witn this; g t, when the piipe section has ~' l, it can usually be repaired by replacing one of the two portions, without removing the whole section This is done for example by removal of the bolts 18 connecting the l ~ ' l flanges, and by removal of bolts whi.ch connect the a~ ' end flange portions 12a, 12b to adjacent sections. During this ll r I t, the pipe section portion which 15 remains in place holds the adjoining pipeline parts at the correct spacing and thus gives less alignment problems than the ~~ r~ ~ ' of a whole section.

Figure lb shows a similar straight pipe section, but withou~ the end flanges. In this form, the ends of the pipe section are provided with c.., ~ ,l grooves, which allow the end of the section to mate with a suitable fitting. To ~ ' these 20 flttings, the I " ' ' flamges 16' are set back at A fron the ends of the pipe. The ~ ~18276~

nature of the flanges, bolt holes, and alignment tabs are the same as in the first ; 'lC'' Figure 2a shows a pipe section in accordance with the invention which is in the form of a tee fitting having flamges 12 for attachment to other pipe sections. The fitting has 5 opposed inlet and outlet ports with a common axis, and a third port . "
with a main l,ai~b~ between the other ports. The fitting is divided into upper and lower body ponions 20a amd 20b about a central plane of symmetry P, the body portions beimg identical but of opposite hand,i.e~ mirror images of each other. Each body portion has a straight flange 22 connecting the inlet and outlet port ends, amd a 0 pair of flanges 23 which are coplanar with flange 22 but are curved when viewed y to tbie plane of symmetry. The flanges 22 and 23 are comnected by nuts and bolts, to allow the tee section to be split, and for this purpose the flamges 12 are also split into upper and lower flange portions 12a and 12b divided by the plame of symmetry. Either the upper or lower body portion can be replaced i _L~
15 of the other portion by removal of the bolts holding the flanges 12a or 12b to adjacent pipe sections, and removal of the bohs connecting the flanges 22 and 23.

Figure 2b shows a further tee section which is similar to that of Figure 2a except that instead of the flanges 12, the ends of tbe tee are grooved, as with the pipe section of Fig lb, to mate witn suitable: The flanges 22' and 23' are the same as 20 flanges 22 and 23 of the previous: ' ' t, except in tbat they are set back from - 21~27~3 the ends of the section to a ~.' ' the COMectors.

Figure 3a shows a 90 elbow having end flanges 12. The whole titting, including flanges 12, is split r ~ , into top and bottom portions about a plane of symmetry which is also the plane of curvature. The top and bottom portions are the 5 same but of opposite hamd. The portions are joined by outer and inner flangw 25 and 26 lw~ , which have coplanar mating surfaces which meet at the plane of symmetry, and which are curved whe n viewed p. . ~ to this plane to follow the curvature of the tee a~is. The flanges are normally held together by nuts and bolts 18, these being removable to allow lcl h of the upper or lower portion of tbe 10 tee. Figure 3b shows a similar ~ but in wbich the ends are grooved as with the Figure Ib section, and the flanges 25' and 26' being set back from the ends of the fltting to Figures 4a and 4b show 22.5 elbows which are generally similar to those of Figures 3a and 3b ~ Lv~,ly, except in being shorter and havmg lws curvatltre;
15 ~ nl- ~ ' 1 parts are similarly referenced.

Figure 5a shows a wye or branch connector having a main, generally cylindrical portion 30 providing a p~ wa,y e~:tending between inlet and outlet ports provided with flangw 12 and 12', this ~ ~s~wl~ with a side branch 31 leading to a tb rd port with another flange 12". Again, upper amd lower portions of ~ ~8276~

the coMector are identical but of opposite hand, and the connector is split along its plane of symmetry into top and botlom portions each having half of the flanges 12, 12' and 12", these portions also each having a straight edge flange 32 and two shorter, curved edge flanges 33 and 34, all the edge flanges being coplanar and 5 meeting at the plane of symme~ry. Figure Sb shows a similar wye connector, also split along the plane of symmetry, but designed for grooved end pipe connectors.

The connectors described above have been, in effect, split along their plane of symmetry, so that each portion is a mirror image or opposite hand version of the other portion. This is convenient for ~ ci, but may not be the best ~ v for 0 the purposes of this invention. For e~:ample, it often happens that most of the wear in a fitting such as an elbow occurs on the outside of the bend, with little wear on the inside. With an elbow of the kind shown in Figure 3a, for example, wear on the outside of the bend will requnre thal: both portions be replaced. To avoid tbis, the fittings may be designed so that they are connected by joints which are ~.1 " ' to the plane of symmetry or of culvature, the joints being curved to follow the curvature of the fitting.

As an e~ample, Figure 6a shows an elbow which is similar to that of Figure 3a in having end flanges 12 joined by a body portion with a 90 bend, but in which the elbow is split I ~ mto an inner body portion 40 and am outer body portiorl 42, the portions having inner and outelr mating flanges 45, 46 ~ wbich meet ~ 2182763 along curved paths which follow the curved axis of the elbow. As before, these flanges are normally held together by nuts and bolts 18. The end flanges 12 are similarly split into ilmer and outer portions on lines ~ to the meeting planes of the flamges, again being pe, I " ' to the plane of symmetry. Figure 6b 5 shows a silmilar elbow suitable for grooved end pipe connectors.

Figures 7a amd 7b show versions of a tee connector which is split I ~ , along two planes, each P~ l- to the plane of symmetry. The fitting has an inlet end port 51 amd an outlet end port 52 connected by a main ~la~ .,wa,~ and has a third port 53 - " ~ with the ~a~ ay~ all these ports Iying in a central plane 10 of symmetry. The fitting is split into three portions including a main I g ' I, semi-cylindrical portion 54 e~tending between the inlet and the ou~det port and defining the outer side of the ~ and havmg I ~ ' I, radially projecting flanges 55 along its edges Iying ~i.l ' ' to the central plane. The fitting also includes two angled portions 56 and 57 each having one pair of flamges 58 arranged to mate with one part of each of the 1~ " ' flanges 55, and a second pair of flanges 59, 60 also Iying in a plane P~ ' ' to the central plane and aligned with the axis of the third port 53. The second pair of flanges 59 of one of the angled portions mate with the second pair of flanges 60 of the second angled portion, all the mating flamges being comnected by removable fastening means to allow 1~,- of one of said 20 three portions while the others remain in place.

~:L82763 In Figure 7a the end flanges 12 are also shown split along the pl~mes P' and P",forming fl mge portions 12i and 120, for the end ports, and portions 12a amd 12b for the third port. In Figure 7b, the tee has no end flanges, being designed for grooved end 5 Figure 8 shows am elbow which is similar to that of Figure 6a, except for being a 22.5 elbow.

Figure 9 shows a wye connector which is similar to the tee connector of Figure 7a, and im which like parts are similarly referenced.

It will be Imderstood that all of tbe . ' ' preferably have the following o features:

(a) Aligmnent tabs 19 on the flamges to assist in their assembly;

(b) Gaskets between the fl~mges;

(c) Inner liners fitted into the I ~ ' ' portions, and I ~ at the ' edges of the portinns; and (d) End flamges 12, where present, are split to provide one part for each portion of the pipe section.

In each case, the procedure for producing the pipe section (including fittings) from a ~,u... ..v~ u.~l pipe section can include the following steps:

(a) splitting the pipe section by cutting in half, or dividing into three portions as required;

(b) cutting out suitable ~ L,ir ' ' flanges, bending these if necessary, and forming the bolt holes;

(c~ welding the flanges to the edges of the pipe section por~ions;

(d) gluing or otherwise adhering a suitable liner portion to the inside of û each the pipe section portion; and (e) assembling the parts with suitable gaskets and bolting the flamges together.

Claims

1. A pipe section suitable for connection to other pipe sections to make a pipeline, comprising several longitudinal portions connected by longitudinal joints, each joint including a pair of longitudinal flanges extending along, and projecting radially from, edges of adjacent longitudinal portions, said flanges being connected together by a series of fastening means which normally hold the flanges together in sealed relationship but which are removable to allow replacement of one of the longitudinal portions while others of said portions remain in place in the pipeline.

2. A pipe section according to claim 1, wherein the pipe section comprises two of said longitudinal portions which are symmetrical about a central plane of the section, each said portion having a main curved body part with one of said longitudinal flanges extending along each of its edges, said flanges of each portion being coplanar, and all said flanges meeting at said central plane.

3. A pipe section according to claim 2 in the form of a cylinder, each portion forming one-half of said cylinder.

4. A pipe section according to claim 2 in the form of an elbow, and comprising two said portions which portions are identical but of opposite hand, and wherein said joints are located in the plane of curvature of said elbow which coincides with said central plane.

5. A pipe section according to claim 2 in the form of a tee or wye junction fitting, and wherein the junction fitting is formed of two of said portions which are identical but of opposite hand.

6. A pipe section according to claim 1 in the form of an elbow, and wherein said longitudinal portions include a radially inner portion and a radially outer portion, and wherein said longitudinal joints are curved joints which are perpendicular to a central plane of curvature of the elbow and which follow the curvature of a central axis of the elbow.

7. A pipe section in the form of a tee or wye fitting having an inlet end port and an outlet end port connected by a passageway, and having a third port communicating with said passageway, all said ports lying in a central plane of symmetry, characterised by comprising three portions including a main longitudinal outer portion extending between the inlet and the outlet port and defining an outer surface of said passageway, and having longitudinal, radially projecting flanges along its edges and lying perpendicular to said central plane, and two angled inner portions each having one pair of flanges arranged to mate with one part of each of said longitudinal flanges and a second pair of flanges lying in a plane perpendicular to said central plane and aligned with the axis of the third port, the second pair of flanges of one angled portion mating with the second pair of flanges of the second angled portion, all said mating flanges being connected by removable fastening means to allow replacement of one of saidthree portions while the others remain in place.

8. A pipe section according to claim 1, wherein said fastening means include bolts, and wherein gaskets are provided between said flanges.

9. A pipe section according to claim 1, having circular end flanges provided with bolt holes, said end flanges being split at said joint.

10. A pipe section according to claim 1, wherein each portion has a liner capable of resisting abrasive or corrosive material.

11. A pipe section according to claim 10, wherein said liner is formed of material selected from the group comprising lubber, polyurethane, and resin.

12. A pipe section according to claim 10, wherein said liner is formed of cement.

13. A pipe section according to claim 10, wherein said liner is formed of ceramic material.

14. A pipe section according to claim 10, wherein said liner is formed from glass.