GB2164876A - Helically wound ducting - Google Patents
Helically wound ducting Download PDFInfo
- Publication number
- GB2164876A GB2164876A GB08523793A GB8523793A GB2164876A GB 2164876 A GB2164876 A GB 2164876A GB 08523793 A GB08523793 A GB 08523793A GB 8523793 A GB8523793 A GB 8523793A GB 2164876 A GB2164876 A GB 2164876A
- Authority
- GB
- United Kingdom
- Prior art keywords
- strip
- ducting
- smooth
- turn
- corrugations
- 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.)
- Granted
Links
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
- F16L11/00—Hoses, i.e. flexible pipes
- F16L11/14—Hoses, i.e. flexible pipes made of rigid material, e.g. metal or hard plastics
- F16L11/16—Hoses, i.e. flexible pipes made of rigid material, e.g. metal or hard plastics wound from profiled strips or bands
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
- B21C37/12—Making tubes or metal hoses with helically arranged seams
- B21C37/123—Making tubes or metal hoses with helically arranged seams of coated strip material; Making multi-wall tubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
- B21C37/12—Making tubes or metal hoses with helically arranged seams
- B21C37/124—Making tubes or metal hoses with helically arranged seams the tubes having a special shape, e.g. with corrugated wall, flexible tubes
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
- Duct Arrangements (AREA)
Abstract
The flue liner ducting is made from a helical coil of a strip (1) of stainless steel. The strip (1) is divided across its width into a portion (10) having several corrugations (11 to 14) along its length, and a portion (20) that is smooth and of equal width. The smooth portion (20) of one turn of the coil overlaps the inside surface of the corrugation portion of an adjacent turn with the first corrugation (11) of the outer turn being swaged (3) onto the last corrugation (14) of the inner turn. The ducting has a smooth inner surface and is bendable. <IMAGE>
Description
SPECIFICATION
Ducting
This invention relates to ducting.
The invention is more particularly concerned with bendable ducting of corrugated material such as for use in lining flues.
Conventional flue liner ducting is formed from a strip of metal, such as stainless steel, which is corrugated along its length. The strip is wound into a helix with overlapping edges which are swaged together to produce tubular ducting with helical corrugations. The corrugations give the ducting a degree of bendability which enables it to be bent around corners, whilst giving it a relatively high radial rigidity.
With such ducting, because the strip is corrugated, the inner surface of the ducting will also be corrugated. This is a disadvantage for several reasons, in that, the corrugations impede free flow of gas along the ducting, they encourage the build up of soot or other combustion products on the inner surface of the ducting, and they hinder condensation running down the inner wall of the ducting, thereby encouraging corrosion.
Attempts have been made to produce ducting with a smooth inner surface but this tends to be difficult to bend and involves the use of two separate components, thereby complicating manufacture.
It is an object of the present invention to provide ducting, and strip material for the manufacture of ducting, by which these disadvantages can be alleviated.
According to one aspect of the present invention there is provided ducting comprising a strip of material formed into a helical coil with overlapping portions joined together, the strip being divided across its width into a smooth portion and a portion with a plurality of corrugations extending along the length of the strip, and the smooth portion of one turn of the coil overlapping the inside surface of the corrugated portion of an adjacent turn and providing a smooth inside surface to said ducting.
The smooth portion and the portion with corrugations preferably have substantially the same width across the strip. The strip is preferably of a metal and may be of a stainless steel. A corrugation at one edge of the strip of one turn preferably overlaps a corrugation adjacent the smooth portion of the strip of an adjacent turn. Overlapping portions of the strip may be joined together by swaging together overlapping corrugations.
According to another aspect of the present invention there is provided a strip for ducting, the strip being divided across its width into a smooth portion and a portion with a plurality of corrugations extending along its length, such that the strip can be rolled into a helical coil with the smooth portion of one turn of the coil overlapping the inside surface of the corrugated portion of an adjacent turn and providing a smooth inside surface to the coil.
The smooth portion and the portion with corrugations may have substantially the same width across the strip. The strip is preferably of a metal and may be of a stainless steel.
Flue liner ducting and strip material for making such ducting, in accordance with the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of the strip material;
Figures 2 and 3 show steps in the manufacture of the ducting; and
Figure 4 is a partly cut-away view of the complete ducting.
With reference first to Fig. 1, the flue liner ducting is made from a length of a stainless steel strip 1, although other materials such as mild steel, nickel alloys, and aluminium could be used. The strip 1 is about 30mm wide and is divided across its width into a corrugated portion 10 and a smooth portion 20 of equal width. The corrugated portion 10 has four parallel corrugations 11 to 14 that are equally spaced from one another and run the length of the strip 1. The first corrugation 11 is formed along one edge of the strip.
With reference now to Fig. 2, the strip 1 is wound helically on a cylindrical mandrel 2 to form a coil. More particularly, the first corrugation 11 of one turn of the strip 1, that is, the corrugation at one edge, is positioned on top of the last corrugation 14 of a preceding turn of the strip, that is, the corrugation adjacent the smooth portion 20, so that the corrugated portion 10 of one turn overlies the smooth portion an adjacent turn.
The overlying turns of the strip 1 are joined together in the manner shown in Fig. 3, by swaging the overlying corrugations 11 and 14 such as with a roller 3. In this way, one corrugation of each turn is crimped to a corrugation of an adjacent turn to complete the ducting.
The swaged joint is not gas-tight but it will be appreciated that alternative joints, or sealing strips or compounds could be used where gas-tight joints are necessary.
With reference to Fig. 4, it can be seen that the completed ducting 4 has a helically corrugated outer surface 40 and a smooth inner surface 41 provided by the smooth portions 20 of the metal strip 1. The ducting 4 can be readily bent about its length since the overlapping smooth portion 20 can slide over adjacent turns.
The smooth inner surface 41 of the ducting reduces turbulence at the wall of the ducting thereby ensuring smooth gas flow along the ducting. The collection of soot and other combustion products can also be reduced. Condensed liquids on the wall of the ducting will flow down the ducting enabling efficient drainage and reducing corrosion. The smooth inner surface of the ducting also enables it to be cleaned easily by passing a brush up the inside of the ducting. The ducting is easy to make, and requires only one component, namely the strip material. The ducting can be light in weight and have good bendability whilst retaining radial rigidity and efficient sealing.
Claims (14)
1. Ducting comprising a strip of material formed into a helical coil with overlapping portions joined together, wherein the strip is divided across its width into a smooth portion and a portion with a plurality of corrugations extending along the length of the strip, and the smooth portion of one turn of the coil overlaps the inside surface of the corrugated portion of an adjacent turn and provides a smooth inside surface to said ducting.
2. Ducting according to Claim 1, wherein the smooth portion and the portion with corrugations have substantially the same width across the strip.
3. Ducting according to Claim 1 or 2, wherein the strip is of a metal.
4. Ducting according to Claim 3, wherein the strip is of a stainless steel.
5. Ducting according to any one of the preceding claims, wherein a corrugation at one edge of the strip of one turn overlaps a corrugation adjacent the smooth portion of the strip of an adjacent turn.
6. Ducting according to any one of the preceding claims, wherein overlapping portions of the strip are joined together by swaging together overlapping corrugations.
7. Ducting substantially as hereinbefore described with reference to the accompanying drawings.
8. A strip for ducting, wherein the strip is divided across its width into a smooth portion and a portion with a plurality of corrugations extending along its length, such that the strip can be rolled into a helical coil with the smooth portion of one turn of the coil overlapping the inside surface of the corrugated portion of an adjacent turn and provides a smooth inside surface to the coil.
9. A strip according to Claim 8, wherein the smooth portion and the portion with corrugations have substantially the same width across the strip.
10. A strip according to Claim 8 or 9, wherein the strip is of a metal.
11. A strip according to Claim 10, wherein the strip is of a stainless steel.
12. A strip substantially as hereinbefore described with reference to the accompanying drawings.
13. Ducting made from a strip according to any one of Claims 8 to 12.
14. Any novel feature or combination of features as hereinbefore described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB848424429A GB8424429D0 (en) | 1984-09-27 | 1984-09-27 | Ducting |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8523793D0 GB8523793D0 (en) | 1985-10-30 |
| GB2164876A true GB2164876A (en) | 1986-04-03 |
| GB2164876B GB2164876B (en) | 1987-07-08 |
Family
ID=10567352
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB848424429A Pending GB8424429D0 (en) | 1984-09-27 | 1984-09-27 | Ducting |
| GB08523793A Expired GB2164876B (en) | 1984-09-27 | 1985-09-26 | Helically wound ducting |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB848424429A Pending GB8424429D0 (en) | 1984-09-27 | 1984-09-27 | Ducting |
Country Status (5)
| Country | Link |
|---|---|
| BE (1) | BE903326A (en) |
| DE (1) | DE3534237A1 (en) |
| FR (1) | FR2570624B1 (en) |
| GB (2) | GB8424429D0 (en) |
| NL (1) | NL8502628A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB940888A (en) * | 1961-01-26 | 1963-11-06 | Rheinmetall Gmbh | Method of manufacturing threaded spindles |
| GB1435264A (en) * | 1973-09-27 | 1976-05-12 | Pacific Roller Die Co Inc | Double wall helical pipe pipe forming method and strip configu ration |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1282312A (en) * | 1961-01-27 | 1962-01-19 | Rheinmetall Gmbh | Method for manufacturing threaded rods, in particular operating screws |
| US3926222A (en) * | 1973-12-18 | 1975-12-16 | Hancock Brick & Tile Co | Corrugated tubing with integral coupling means thereon |
| DE2645946C2 (en) * | 1976-10-12 | 1982-08-19 | Witzenmann GmbH, Metallschlauch-Fabrik Pforzheim, 7530 Pforzheim | Multi-layer corrugated pipe for exhaust pipes of internal combustion engines |
| EP0023242B1 (en) * | 1977-10-18 | 1983-09-07 | Rib Loc Hong Kong Limited | Profiled strips and method of forming tubular articles with these strips |
-
1984
- 1984-09-27 GB GB848424429A patent/GB8424429D0/en active Pending
-
1985
- 1985-09-26 BE BE0/215643A patent/BE903326A/en not_active IP Right Cessation
- 1985-09-26 GB GB08523793A patent/GB2164876B/en not_active Expired
- 1985-09-26 NL NL8502628A patent/NL8502628A/en not_active Application Discontinuation
- 1985-09-26 DE DE19853534237 patent/DE3534237A1/en active Granted
- 1985-09-27 FR FR8514501A patent/FR2570624B1/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB940888A (en) * | 1961-01-26 | 1963-11-06 | Rheinmetall Gmbh | Method of manufacturing threaded spindles |
| GB1435264A (en) * | 1973-09-27 | 1976-05-12 | Pacific Roller Die Co Inc | Double wall helical pipe pipe forming method and strip configu ration |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8424429D0 (en) | 1984-10-31 |
| FR2570624B1 (en) | 1994-02-04 |
| GB2164876B (en) | 1987-07-08 |
| BE903326A (en) | 1986-01-16 |
| DE3534237C2 (en) | 1993-05-27 |
| FR2570624A1 (en) | 1986-03-28 |
| NL8502628A (en) | 1986-04-16 |
| GB8523793D0 (en) | 1985-10-30 |
| DE3534237A1 (en) | 1986-04-03 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732E | Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977) | ||
| PE20 | Patent expired after termination of 20 years |
Effective date: 20050925 |