ZA201008270B - Method of insulating pipe joints - Google Patents
Method of insulating pipe joints Download PDFInfo
- Publication number
- ZA201008270B ZA201008270B ZA2010/08270A ZA201008270A ZA201008270B ZA 201008270 B ZA201008270 B ZA 201008270B ZA 2010/08270 A ZA2010/08270 A ZA 2010/08270A ZA 201008270 A ZA201008270 A ZA 201008270A ZA 201008270 B ZA201008270 B ZA 201008270B
- Authority
- ZA
- South Africa
- Prior art keywords
- mold
- pipe joint
- sealing medium
- mold assembly
- pipe
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims description 41
- 238000007789 sealing Methods 0.000 claims description 29
- 230000015572 biosynthetic process Effects 0.000 claims description 12
- 238000005755 formation reaction Methods 0.000 claims description 12
- 239000006260 foam Substances 0.000 claims description 11
- 239000011347 resin Substances 0.000 claims description 5
- 229920005989 resin Polymers 0.000 claims description 5
- 230000000295 complement effect Effects 0.000 claims description 3
- 230000007613 environmental effect Effects 0.000 claims description 3
- 239000004814 polyurethane Substances 0.000 claims description 3
- 239000004593 Epoxy Substances 0.000 claims description 2
- 230000001939 inductive effect Effects 0.000 claims description 2
- 238000005260 corrosion Methods 0.000 description 11
- 230000007797 corrosion Effects 0.000 description 11
- 239000004264 Petrolatum Substances 0.000 description 9
- 229940066842 petrolatum Drugs 0.000 description 9
- 235000019271 petrolatum Nutrition 0.000 description 9
- 239000000463 material Substances 0.000 description 4
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 238000005266 casting Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000004519 grease Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000013521 mastic Substances 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 1
- 239000002390 adhesive tape Substances 0.000 description 1
- 238000004210 cathodic protection Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
- 239000011800 void material Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
- F16L58/18—Protection of pipes or pipe fittings against corrosion or incrustation specially adapted for pipe fittings
- F16L58/181—Protection of pipes or pipe fittings against corrosion or incrustation specially adapted for pipe fittings for non-disconnectible pipe joints
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Protection Of Pipes Against Damage, Friction, And Corrosion (AREA)
Description
A ’
PEt Cem i \ . \ MII \ | ’ 1 B '
DE _
THIS invention relates to a method of insulating pipe joints, and more particularly but not exclusively, to a method of protecting pipe joints against corrosion.
Many applications exist where sections of pipe are secured to one another : by way of securing brackets, clamps or welding. Once the pipe ends have been secured to one another, a corrosion seal has to be applied to the connection in order to prevent localized corrosion at the pipe joint. The remainder of the pipe has usually already been rendered corrosion resistant, but the joint remains a zone of weakness insofar as corrosion is concerned. :
At present, in the case of couplings a layer of a substance known as petrolatum is typically applied around the pipe joint. The petrolatum mastic is packed about the coupling and a wrap of petrolatum tape is applied to the petrolatum mastic to keep it in place. A final wrap of PVC or PE self adhesive tape is then applied over the petrolatum tape, or alternatively a loose PE bag is circumferentially spread around the protected joint area.
All this is done after the connected pipe has already been placed inside the pipe trench. Although the above process provides at least some corrosion protection, a number of problems are associated therewith. The application
~ . . - 2010/ 0827 N 2. of the grease is a manual process, which is time-consuming and difficult to master. The integrity of the application is also not always consistent, as it is largely dependent on the skill of the person applying the grease layer. As mentioned above, the seal is applied once the pipe has already been positioned in the pipe trench, and the work therefore has to be done in a confined space, and it is also very difficult to inspect the packing to see if it has-been done correctly. The petrolatum system also offers very little mechanical protection, and if there is foot traffic over the ridge of the protected joint the petrolatum layer can be easily displaced. Also, if backfilling of the trench is not carefully controlled, the petrolatum may be displaced, rendering the protection ineffective. It will be appreciated that the quality and integrity of the seal obtained using the petrolatum system is very dependent on the specific individual applying the seal, and it is therefore difficult to obtain consistency. in the case of welded joints a paint or paste is typically painted or sprayed over the welded section. However, these processes frequently result in the formation of bubbles which, if undetected, will result in corrosion of the pipe. In order to prevent this, every bubble has to be detected, for example using a ultrasonic method, and then removed. The void formed during removal must be patched with a suitable filler material, which is an expensive exercise, and one requiring a high degree of skill. The presence of bubbles especially problematic where cathodic protection is utilized. The problem may be partially alleviated if a thicker protection layer is applied to the joint area, but the existing application method renders this approach impractical. :
It is accordingly an object of the invention to provide a method of insulating pipe joints that will, at least partially, alleviate the above disadvantages.
It is also an object of the invention to provide a method of insulating pipe joints that will be a useful alternative to existing methods.
According to the invention there is provided a method of insulating a pipe joint, the method including the steps of: - providing a mold assembly configured and dimensioned to fit around the pipe joint; - locating the mold assembly on the pipe joint in order to form an enclosed volume between the mold and an outer surface of the pipe; - introducing a sealing medium into the enclosed volume in order to form an insulated zone.
There is also provided the method to include the step of inducing a pressure less than atmospheric pressure inside the enclosed volume.
There is also provided for the sealing medium to be injected into the enclosed volume.
Preferably the sealing medium is in the form of an epoxy or a PU thermosetting resin. There is also provided for the sealing medium to be in the form of settable foam, more preferably a polyurethane (PU) foam.
The method may include the steps of allowing the sealing medium to cure. : The method may also include the step of applying a heat shrink layer around the cured sealing medium, alternatively around the mold encapsulating the liquid sealing medium, in order to form a secondary environmental seal around the pipe joint.
. -
According to a further aspect of the invention there is provided a mold assembly for use in insulating a pipe joint, the mold assembly including: a mold body configured and dimensioned to be locatable about the perimeter of the pipe joint to be sealed, and to be at least partially spaced apart from a surface of the pipe when installed; : an inlet port for receiving a sealing medium; and an outlet port through which a vacuum can be induced inside the mold.
According to a further aspect of the invention there is provided a mold assembly for use in insulating a pipe joint, the mold assembly including: an operatively lower mold configured and dimensioned to fit around a lower halve of the pipe joint, an operatively upper mold configured and dimensioned to fit around an upper halve of the pipe joint, the lower mold and the upper mold including complementary engagement formations that enables the molds to be locatable on top of one another.
Preferred embodiments of the invention are described by way of a non- limiting examples, and with reference to the accompanying drawings in which:
Figure 1 is a perspective view of an operatively upper mold of the mold assembly used in the method of insulating a pipe joint in accordance with a first embodiment of the invention;
Figure 2 is a perspective view of an operatively lower mold of the mold assembly used in the method of insulating a pipe joint in accordance with a first embodiment of the invention;
Figure 3 is a perspective view of the mold assembly mounted on a pipe joint to be insulated in accordance with a first embodiment of the invention;
Figure 4 is a cross-sectional side view of a pipe joint and the mold assembly in accordance with a first embodiment of the invention; and
Figure 5 is a cross-sectional side view of a pipe joint and a mold assembly of a second embodiment of the invention.
Referring to Figures 1 to 4, in which like numerals indicate like features, a non-limiting example of a mold assembly in accordance with a first embodiment of the invention is generally indicated by reference numeral 10. The mold assembly 10 includes an operatively upper mold 20 and an operatively lower mold 30, which are used to construct the mold assembly 10, which is used in a novel method of insulating a pipe joint 15 against corrosion.
A typical pipe joint 15 is schematically shown in Figure 4, and comprises a first pipe end 15.1 and a second pipe end 15.2 that are located end to end, and subsequently secured to one another using a bolted pipe clamp 15.3.
Once the pipe ends 15.1, 15.2 have been secured to one another a corrosion seal is applied to the pipe joint using the mold assembly 10.
The mold assembly 10 includes an operatively upper mold 20 and an operatively lower mold. The upper mold 20 includes a shell 21 made of a thin polymeric material, and which is configured and dimensioned to fit around the pipe clamp 15.3, with allowance being made for bolts (not shown) extending from the pipe clamp 15.3. Longitudinal flanges 22 extend from opposite sides of the shell, and are profiled to match the curve of an outer surface of the pipe ends. This enables a partial seal to be formed between the mold 20 and the pipe end, and prevent the sealing - medium from leaking from the mold assembly at the interface between the mold and the pipe. A circumferential flange 23 furthermore extends radially outwardly from the shell 21, and includes an engagement formation 24, in the form of a groove formation, for receiving an engagement formation 34, in the form of a tongue formation, that extends from a complementary flange 33 extending from the operatively lower mold 30. A casting aperture is provided in an upper surface of the upper mold 30 for use in introducing a sealing medium 40 into the mold assembly 10.
The lower mold 30 also includes a shell 31 made of a thin polymeric oo material, and which is configured and dimensioned to fit around the pipe clamp 15.3, with allowance again being made for bolts (not shown) extending from the pipe clamp 15.3. Longitudinal flanges 32 extend from opposite sides of the shell, and are profiled to match the curve of an outer surface of the pipe ends. The longitudinal flanges 32 of the lower mold 30 and the longitudinal flanges 22 of the upper mold 20 are aligned so as to form a substantially continuous annular flange when viewed from the side.
The lower mold 30 also includes an outwardly extending flange 33, having a tongue formation 34 standing proud thereof for engaging the groove formation 24 provided in the flange 23 of the upper mold. :
In use, the two halves 20, 30 are located over the pipe joint 15 and aligned in order for the outwardly extending flanges 23, 33 to abut. These flanges may now be secured to one another in various different ways to form the mold assembly 10. The composite mold assembly 10 now defines an enclosed volume between the outer surface of the pipe ends 15.1, 15.2 and pipe clamp 15.3, and an inner surface of the shells 21, 31 of the molds 20, 30.
BE A sealing medium 40 is subsequently introduced into the enclosed volume through the casting aperture 25 in the upper mold 20. The sealing medium may be settable, expanding foam which is poured into the mold assembly, and which is then left to cure. Once the foam is fully expanded and cured, the mold assembly may be removed, but it is also foreseen that the mold assembly can be left in position on order to protect the foam. The foam and/or the mold assembly surrounding the foam may finally also be shrink wrapped by way of a heat shrink process so as to enhance the integrity of the seal. In accordance with another embodiment of the invention a liquid or gel may be used as a sealing medium. In this case the sealing medium will not cure, and the mold assembly 10 will have to remain in place to contain the sealing medium. However, in both embodiments the common denominator resides in the sealing medium being applied using a mold assembly which ensures uniform distribution and ‘adequate support of the sealing medium.
The inventors believe that the above method of insulating a pipe joint, and in particular a pipe coupling, in accordance with a first embodiment of the invention, in order to protect the pipe joint against corrosion will address many of the problems experienced at present with existing sealing technology. The seal formed will be of a high integrity, as the person creating the seal only needs to pour the sealing medium into the mold assembly. The seal will also be of higher mechanical integrity, and will not easily be dislodged or damaged. In addition to all the advantageous set out above, the seal will also be formed in a substantially reduced time period, as the process in inherently less time-consuming.
A second embodiment of the mold assembly in accordance with the invention is generally indicated by reference numeral 100, and is schematically shown in Figure 5. In this case the method is particularly suitable for use on welded joints, although it will be appreciated that the method, and thus the mold assembly used in this method, is not limited to welded joints. It should be noted that this embodiement is only schematically illustrated in Figure 5, and that the actual mold assembly can take many different forms.
In one example, a sturdy sheet 101 of about 200mm was wrapped about the area to be insulated, with a 3 to 5mm gap 102 being left between an inner surface of the sheet and the outer surface of the pipe. Seals 104 were provided at the edges of the sheet 101 thus resulting in a circumferential annular channel being formed between the pipe and the sheet 101. The spacing and seal between the sheet 101 and the pipe 103 was achieved by applying a self-adhesive foam or rubber strip having a thickness of between 3 and 5mm to the mould, but it will be appreciated that spacing ridges may also be integrally extruded with the sheet. A first port 105 and a second port 106 were also provided, both being in flow communication with the enclosed volume formed by the mold assembly 100. A release agent was furthermore applied to an inner surface of the . sheer 101, but it will be appreciated that the selection of a self releasing material for the manufacturing of the sheet would also have sufficed. The first port 105 was subsequently connected to a vacuum pump, whereas the second port 106 was brought in flow communication with a resin source.
The vacuum pump therefor induces a vacuum inside the enclosed volume,
: | I” causing the resin to be drawn into the enclosed volume. It was found that this process resulted in the formation of a seal that was substantially free of bubbles, which is essential for the particular application. It is believed that the results will be even better if the resin is introduced under pressure using an injection apparatus.
It was found that the above method was surprisingly advantageous in the formation of seals in the application described above, as the absence of bubbles is a very important requirement when it comes to the sealing of pipe joints. Known techniques have therefore been combined in a novel and inventive manner to result in a new method having unexpected results in the particular application. :
The inventors believe that the above method of insulating a pipe joint in order to protect the pipe joint against corrosion will also address many of the problems experienced at present with existing sealing technology, especially insofar as the sealing of welded joints are concerned. The seal formed will be of a high integrity, as the person creating the seal only needs to install the mold assembly, and no particular application skill is required. oo The seal will also be of higher mechanical integrity than existing painted or sprayed seals, and will not easily be dislodged or damaged. Increased seal thickness (3 — 5mm as opposed to 1.5mm with painted or sprayed seals) is also achievable. In addition to all the advantageous set out above, the seal will also be formed in a substantially reduced time period, as the process in inherently less time-consuming. The process will furthermore take place in an enclosed mould, with will reduce environmental impacts on the applications and formation of the seal.
It will be appreciated that the above are only two embodiments of the invention and that there may be many variations without departing from the spirit and/or the scope of the invention.
Claims (10)
1. A method of insulating a pipe joint, the method including the steps of: providing a mold assembly configured and dimensioned to fit around the pipe joint; locating the mold assembly on the pipe joint in order to form an enclosed volume between the mold and an outer surface of the pipe; introducing a sealing medium into the enclosed volume in order to form an insulated zone.
2. The method of claim 1 including the step of inducing a pressure lower than atmospheric pressure inside the enclosed volume.
3. The method of claim 1 or claim 2 in which the sealing medium is injected under pressure into the enclosed volume. :
4. The method of any one of the preceding claims in which the sealing medium is in the form of an epoxy or a resin.
} 5. The method of any one of the preceding claims in which the sealing medium is in the form of settable foam.
6. The method of claim 5 in which the settable foam a polyurethane (PU) foam.
7. The method of any one of the preceding claims including the step of allowing the sealing medium to cure.
8. The method of any one of the preceding claims including the step of applying a heat shrink layer around the cured sealing medium, in order to form a secondary environmental seal around the pipe joint.
9. A mold assembly for use in insulating a pipe joint, the mold assembly including: a mold body configured and dimensioned to be locatable : about the perimeter of the pipe joint to be sealed, and to be at least partially spaced apart from a surface of the pipe when installed; an inlet port for receiving a sealing medium; and an outlet port through which a vacuum can be induced inside the mold.
10. A mold assembly for use in insulating a pipe joint, the mold assembly including: an operatively lower mold configured and dimensioned to fit around a lower halve of the pipe joint; an operatively upper mold configured and dimensioned to fit around an upper halve of the pipe joint; the lower mold and the upper mold including complementary engagement formations that enables the molds to be locatable on top of one another. Dated this 18" Day of November 2010 Spoor & Fisher Applicant's Patent Attorneys
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA200908135 | 2009-11-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| ZA201008270B true ZA201008270B (en) | 2011-10-26 |
Family
ID=44059264
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| ZA2010/08270A ZA201008270B (en) | 2009-11-18 | 2010-11-18 | Method of insulating pipe joints |
Country Status (2)
| Country | Link |
|---|---|
| WO (1) | WO2011061704A1 (en) |
| ZA (1) | ZA201008270B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2527187B (en) * | 2013-08-09 | 2016-08-03 | Pipeline Induction Heat Ltd | A vehicle for induction heating a bent pipeline section |
| DE102014100296A1 (en) * | 2014-01-13 | 2015-07-16 | Witzenmann Gmbh | Flexible conduit element with insulation |
| FR3018333A1 (en) | 2014-03-10 | 2015-09-11 | Saint Gobain Performance Plast | |
| EP3670998B1 (en) | 2018-12-18 | 2022-11-16 | Nexans | Coupling for fluid conduits |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3258512A (en) * | 1963-05-09 | 1966-06-28 | Archibald T Flower | Method of applying a rigid unicellular polyurethane foam coating to pipe fittings |
| US4323526A (en) * | 1980-06-02 | 1982-04-06 | Rubco Products, Inc. | Method for sealing pipe joints |
| US6257282B1 (en) * | 1998-10-28 | 2001-07-10 | Mve, Inc. | Vacuum insulated pipe |
-
2010
- 2010-11-18 ZA ZA2010/08270A patent/ZA201008270B/en unknown
- 2010-11-18 WO PCT/IB2010/055261 patent/WO2011061704A1/en active Application Filing
Also Published As
| Publication number | Publication date |
|---|---|
| WO2011061704A1 (en) | 2011-05-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7028716B2 (en) | Method for rehabilitating an existing pipe | |
| JPS61236994A (en) | Method of sealing joining section or leakage section | |
| CN104321489B (en) | For rebuilding the system of pipe well | |
| ZA201008270B (en) | Method of insulating pipe joints | |
| WO2015023211A1 (en) | Method for protecting a welded joint between pipes having an interior coating | |
| US6217688B1 (en) | Method of repairing a flanged pipe joint | |
| US20180282978A1 (en) | Manhole base liner and method for manufacturing a manhole base liner | |
| US10683959B2 (en) | Method and apparatus for repairing a length of pipe or a main/lateral pipe junction | |
| JP6144125B2 (en) | Pipe lining method and pipe lining pipe | |
| US8544505B1 (en) | Pre-stressed concrete pipe | |
| US10465825B2 (en) | Method of joining pipes and fittings with mechanical restraint members | |
| US20170219155A1 (en) | Expandable pipe including a liner for restoring a conduit | |
| US10603818B2 (en) | Method and apparatus for producing a sewer pipe element | |
| CA3078181C (en) | Device for the internal monolithic insulation of a welded pipeline joint | |
| US3888454A (en) | Means for forming a seal about a conduit | |
| JP2005288786A (en) | Method for repairing protective pipe with cable placing finished | |
| US20210131603A1 (en) | Pipeline Repair Assembly and Method Having Hydrophilic Containment Bands | |
| JPH0617072B2 (en) | Pipe line lining method | |
| JPH079624Y2 (en) | Tube lining terminal fixing structure | |
| WO2007066138A1 (en) | Method and apparatus for renovating a pipe or conduit | |
| JPH087191Y2 (en) | Water stop | |
| JP7404194B2 (en) | How to apply sealant | |
| JPS6246073Y2 (en) | ||
| CN112240451A (en) | Blocking structure for pipeline fracture and disposal method | |
| JPH0320638Y2 (en) |