WO1993016321A1

WO1993016321A1 - Insulation pipe system

Info

Publication number: WO1993016321A1
Application number: PCT/FI1993/000050
Authority: WO
Inventors: Reijo Hautala
Original assignee: R. Hautala Ky
Priority date: 1992-02-17
Filing date: 1993-02-16
Publication date: 1993-08-19
Also published as: DE4390465C2; SE503728C2; SE9402707D0; NO303847B1; FI920678A7; NO943001L; DE4390465T1; NO943001D0; DK170719B1; SE9402707L; AU3501093A; FI920678A0; FI92098B; FI92098C

Abstract

The invention relates to an insulation pipe system comprising insulated piping components, such as insulation pipes (1, 2), fire dampers, dampers, measurement connections and branch tubings, said pipe component comprising an inner pipe (3), an outer pipe (4) and a space between them for insulation material (5). In order that ventilation systems and the like complying with the fire-resistance grading and the provisions could be easily and rapidly accomplished and the amount of work to be done in situ could be minimized, both ends of the piping component are provided with an end flange (6) which substantially covers the space between the inner and outer pipe and which, by being connected to the inner pipe (3) and the outer pipe (4), centers the inner pipe with respect to the outer pipe, said end flange being connected indirectly through its outer circumference (7) to the outer pipe in such a manner that it is fixed to an insulation ring (8) provided in connection with a flange ring (9) on the circumference of the outer pipe so that the end flange is not in direct contact with the outer casing of the piping component.

Description

Insulation pipe system

The invention relates to an insulation pipe system comprising insulated piping components, such as insulation pipes, fire dampers, dampers, measurement connections and branch tubings, said pipe component com¬ prising an inner pipe, an outer pipe and a space between them for insulation material.

The nsulation pipe system of the invention is particularly suitable for use in heat, fire and sound insulated ventilation systems which are achieved by connecting insulation pipes of different lengths and forms to each other. The pipes have typically a diameter within the range of 100 to 1200 mm. It should be noted that the insulation pipe system of the invention can also be used for other applications than ventilation systems. The insulation pipe system can thus be used for conducting other gases, and even water and other liquids. At present, insulation pipes of ventilation systems are still often achieved by insulating a pipe in which a fluid is to flow by insulation material in situ, and mounting an outer casing around the insula¬ tion material. The method is laborious and cannot there- fore be recommended for places where piping must be installed in a short time. Factory-made insulation pipes comprising an inner pipe, an outer pipe and insulation between them have been developed to facilitate and speed up the installation of pipes. The problem with such insulation pipes is, however, the formation of joints during installation. The joints between insulation pipes as well as other piping components must be tight and sufficiently insulated from the environment. With known pipe components the formation of such joints is laborious. The joints are formed in practice in such a manner that an intermediate bushing is disposed between the pipes (and other piping components) to be connected to each other. The intermediate bushing is inserted in the inner pipes and fixed to them by riveting. In order that the riveting could be effected, the insulation material and the outer pipe must be removed from around the inner pipes at the joint. After the riveting, the joint must be insulated, and a casing is mounted around the insulation. What makes the insertion of an inter- mediate bushing even more difficult is that the inner pipe is not always coaxial with the outer pipe surround¬ ing it: during transport of an insulation pipe, the insulation material is packed unequally by the action of vibration and other mechanical load, whereby the inner pipe which was originally coaxial with the outer pipe moves from its original position. By using an intermediate bushing in the installation, it can be ensured that the inner pipes of insulation pipes and other pipe components are aligned with each other co- axially.

Pipings made from known pipe components are also difficult to repair and renovate. This is due to the fact that the changing of a damaged piece of piping requires that the joints be opened, which is very laborious.

The object of the present invention is to remove the above defects. For this purpose the insula¬ tion pipe system of the invention is mainly charac¬ terized in that both ends of the piping component are provided with an end flange which substantially covers the space between the inner and outer pipe and which, by being connected to the inner and outer pipe, centers the inner pipe with respect to the outer pipe, said end flange being connected indirectly through its outer circumference to the outer pipe in such a manner that it is fixed to an insulation ring provided in connection with a flange ring on the circumference of the outer pipe so that the end flange is not in direct contact with the outer casing. Preferred embodiments of the insulation pipe system of the invention are disclosed in appended claims 2 to 10.

The most significant advantages of the insula¬ tion pipe system of the invention are that ventilation systems and the like complying with the fire-resistance grading and the provisions can be easily and rapidly accomplished, as the amount of work to be done in situ is minimized: the ducts and pipings of different lengths and forms can be achieved by combining piping components of the invention with different lengths and forms, including curved pipes, fire dampers, dampers, measure¬ ment connections, branch tubings, transforming fittings, etc. For the last-mentioned purpose, insulation pipes of the invention are available in numerous standard lengths, with which the desired total lengths can be achieved. It is also easy to repair and renovate pipings made from piping components according to the invention. The flanges at the ends of the piping component render it possible to even leave out the intermediate bushings commonly used when insulation pipes are connected to each other. The end flanges also enable the space between the outer and inner pipe to be filled with insulation material after the insulation pipe is finish¬ ed in other respects, for example by employing the blow¬ ing method. In the following, the invention will be described in greater detail by means of a preferred embodiment with reference to the accompanying drawing, in which Figure 1 is a side view of two insulation pipes of the invention disposed in alignment with each other for joining,

Figure 2 is a view along arrows II - II of Figure 1, and

Figure 3 is a view along arrows III - III of Figure 1.

The straight insulation pipe 1 of Figure 1 is depicted as cut off so that its both, completely similar ends are visible. The insulation pipe 2 on the left is of the same type and has completely similar ends as the insulation pipe 1. The insulation pipe 1 comprises an inner pipe 3 made of steel, an outer pipe 4 made of steel, and a space between them filled with insulation material 5. Both ends of the insulation pipe 1 are provided with an end flange 6 which is made of steel and covers the space between the outer and inner pipe so that the insulation material 5, for example mineral wool, cannot escape. The outer circumference 7 of the end flange 6 is fixed through an insulation ring 8 made of silicone rubber to a flange ring 9 which is an integral part of the outer pipe 4, and the inner circum¬ ference of the end flange consists of a tubular part 10 overlapping the inner pipe 3. The end flange 6 is not in metal-metal contact with the outer pipe 4 or the metal part of the flange ring 9. Due to the arrangement described, the inner pipe 3 is centered with respect to the outer pipe 4, and heat is not allowed to be con¬ ducted from the inner pipe 3 to the outer pipe 4 through the end flange 6.

In addition to functioning as a part receiving the outer circumference 7 of the end flange 6 and as a protection for the insulation ring 8, the flange ring 9 also functions as fixing means when the insulation pipes 1, 2 are to be connected to each other by means of a clamping ring 11 to be clamped manually, indicated by a dashed line in Figures 1 and 2. The flange ring 9 comprises a substantially straight surface 12 which is at an angle α = 55° in relation to the outer pipe 4. The surface 12 functions as a clamping surface owing to the fact that the inner circumference 13 of the clamping ring 11 slides along the surface 12 when the clamping ring is clamped (and its diameter is made smaller), whereby the insulation pipes 1, 2 to be connected to each other are tightened or pressed against each other. The angle α may vary within the range of about 40 to 70° while this function is maintained. If the angle is too great, the axial clamping distance is very short, which sets greater requirements for the tolerances of the insulation pipe components and complicates installa¬ tion of the clamping ring. If the angle is small, there is the danger that the inner circumference 13 of the clamping ring is not able to slide along the surface 12. The flange ring 9 can be easily achieved on the outer pipe 4 by shaping this.

The flange ring 9 also comprises a surface 14 on the level of the end flange 6, whereby the insulation ring 8 is sufficiently well surrounded so that it remains stationary in the different treatment steps of the insulation pipe.

The tubular part 10 of the end flange 6 com¬ prises two parts 10a and 10b with slightly different diameters, and an annular shoulder 15 at the transition point of these parts. The diameter of the part 10a corresponds substantially to the diameter of the inner pipe 3 or may be a few millimetres greater; the diameter of the part 10b is slightly smaller than the diameter of the inner pipe so that the tubular part 10 can be pushed onto the inner pipe 3 or, to put it more accur- ately, inserted in it. The inner pipe 3 and part 10b of the tubular part 10 overlap a distance of X, which may be quite short, for example 10 to 20% of the diameter of the outer pipe 4. No welding, rivets or other con¬ necting means are needed to mount the tubular part 10 on the inner pipe 3: the annular shoulders 15 function as centering means preventing axial displacements of the inner pipe 3 in relation to the outer pipe 4. The distance of the annular shoulder 15 from the end of the insulation pipe is 15 to 50%, preferably 20 to 40% of the diameter of the outer pipe 4. A coupling or inter¬ mediate bushing 16, indicated by a dashed line, can be installed between the insulation pipes 1 and 2 to be connected to each other if this is considered to improve the durability and safety of the joint. The significance of the intermediate bushing 16 in improving safety resides in that the joint will hold even if the clamping ring 11 should open for some reason.

From Figure 1 it can be seen that the insula¬ tion ring 8 does not completely fill the space defined by the flange ring 9, but a small groove extending round the circumference has been formed at the other upper edge to enable the insulation ring to expand and contract for example when the clamping ring 11 is clamped and a joint is formed between two insulation pipes.

Figure 2 is a section of the insulation pipe 1 taken at II - II of Figure 1. Reference number 17 denotes a manually operated clamping and opening handle of the clamping ring 11. From Figure 3, which shows a view of the end of insulation pipe 1, it is evident that the end flange 6 is not in direct contact with the flange ring 9, but there is a gap 18 filled with insulation material 8 between the end flange and the surface 14. In the above, the invention has been illus¬ trated merely by means of one example, and therefore it should be noted that the invention may vary in its details in many ways within the scope of the appended claims. It is thus conceivable that the flange ring (9) of the insulation pipe or the piping component is not an integral part of the outer pipe. However, in view of the manufacture, such a solution is nowhere near as advantageous. The insulation ring (8) does not neces- sarily have to be of silicone rubber, but some other flexible, preferably heat-resistant material, can also be used. The use of silicone rubber is, however, recom¬ mendable, as its heat-resistance is even as high as about 200°C. Instead of the inclined straight surface (12) of the flange ring, it is possible to use an inclined, slightly curved surface to achieve the clamp¬ ing effect, which contributes to the accomplishment of a tight joint. The end flange can also be perforated. The tubular part (10) of the end flange does not have to comprise two diameters and an annular shoulder even though this is highly recommendable because the annular shoulder centers the inner pipe axially and even the intermediate bushing (16), if the use of such a bushing is desired.

Claims

Claims:

1. An insulation pipe system comprising insulated piping components, such as insulation pipes, fire dampers, dampers, measurement connections and branch tubings, said pipe component comprising an inner pipe (3 ) , an outer pipe (4) and a space between them for insulation material (5), c h a r a c t e r i z e d in that both ends of the piping component are provided with an end flange ( 6 ) which substantially covers the space between the inner and outer pipe and which, by being connected to the inner pipe (3 ) and the outer pipe (4) , centers the inner pipe with respect to the outer pipe, said end flange being connected indirectly through its outer circumference (7) to the outer pipe in such a manner that it is fixed to an insulation ring (8) provided in connection with a flange ring (9) on the circumference of the outer pipe so that the end flange is not in direct contact with the outer casing of the piping component.

2. An insulation pipe system according to claim

1, c h a r a c t e r i z e d in that the flange ring (6) is an integral part of the outer pipe (4) and has been formed by bending the outer pipe.

3. An insulation pipe system according to claim

2, c h a r a c t e r i z e d in that the insulation ring (8) in connection with the flange ring (6) is dis¬ posed within said flange ring.

4. An insulation pipe system according to claim 3, c h a r a c t e r i z e d in that the insulation ring (8) is made of a heat-resistant flexible material.

5. An insulation pipe system according to claim 4, c h a r a c t e r i z e d in that the insulation ring (8) is made of silicone rubber.

6. An insulation pipe system according to claim 2, c h a r a c t e r i z e d in that the profile of the flange ring (9) seen in the direction of the tangent of said flange ring comprises a substantially straight surface (12) at the part thereof extending away from the end of the piping component, said surface being at an angle in relation to the outer pipe and functioning as a clamping surface for an annular clamping ring (11) which is preferably clamped manually and by means of which the piping components (1, 2) disposed end to end can be connected and tightened against each other.

7. An insulation pipe system according to claim 6, c h a r a c t e r i z e d in that the straight surface (12) is at an angle α = approx. 40 to 70° in relation to the outer pipe (4).

8. An insulation pipe system according to claim 6, c h a r a c t e r i z e d in that the profile of the flange ring (9) seen in the direction of the tangent of said flange ring comprises a surface (14) on the level of the end of the piping component.

9. An insulation pipe system according to claim 1, c h a r a c t e r i z e d in that the inner circum¬ ference of the end flange (6) consists of a tubular part (10) the diameter of which corresponds substantially to that of the inner pipe and which overlaps the inner pipe (3).

10. An insulation pipe system according to claim 8, c h a r a c t e r i z e d in that the tubular part (10) comprises two parts (10a and 10b) with slight- ly different diameters, and an annular shoulder (15) at the transition point thereof, whereby the part (10a) with the greater diameter is closer to the end (6) of the piping component than the part (10b) with the smaller diameter, and that the distance of the annular shoulder from the end of the piping component is 15 to 50%, preferably 20 to 40%, of the diameter of the outer pipe (4) .