WO2008113805A1

WO2008113805A1 - Pressure piping

Info

Publication number: WO2008113805A1
Application number: PCT/EP2008/053231
Authority: WO
Inventors: Jürgen Scharkowski
Original assignee: Steuler Industriewerke Gmbh
Priority date: 2007-03-19
Filing date: 2008-03-18
Publication date: 2008-09-25
Also published as: DE102007013061A1

Abstract

The invention relates to pressure piping having a supporting outer layer (1) and an inner layer (2), wherein the outer layer (1) has glass fiber-reinforced plastic and the inner layer (2) has a thermoplastic resin, preferably polypropylene. A lining layer (3) is provided between the outer layer (1) and the inner layer (2). The invention further relates to a corresponding production method. The pressure piping according to the invention minimizes the number of weld seams and improves the reliability of the connection of piping pieces during final assembly.

Description

Penstock

The invention relates to pressure pipes, in particular large-sized pressure pipes, and a corresponding manufacturing method.

Large-sized pressure pipelines have hitherto been made of steel or rubberized steel and, more rarely, of glass fiber reinforced plastic (GRP). In this case, sections are connected by means of known techniques, for example by means of winding tube technology, to form a tube which is separated for transport or for installation in corresponding pipe sections. For final assembly of a pipe, the pipe sections are connected, for example by means of known welding methods.

This results in previously used pressure pipes many seams that represent potential vulnerabilities during subsequent operation. Next wall thicknesses used in such pipes, or the wall thicknesses of inner layers in the tubes, such as a rubber coating, are very low. When mounting the pipe sections, therefore, there is a risk that at a small offset of the pipe sections, in which the pipe sections are not exactly flush or positively connected with each other, a vulnerability is created, which can lead to a defect in the pipe early in operation later.

As a result, substances that are conducted through the pipe, such as wastewater, leak and get into the environment or can be contaminated substances to be transported in the pipe, such as drinking water.

The prior art is further referred to DE 42 37 477 C2, DE 198 41 121 Al and DE 88 03 049 Ul. The object of the invention is to provide an improved penstock and a corresponding manufacturing method, which minimizes the number of connecting seams and improves or facilitates the safety of the connection of pipe sections. Next, the durability of penstocks is to be increased.

The object is achieved with the features of the claims.

The invention is based on the basic idea of arranging a supporting outer layer on a preferably extruded and particularly preferably seamless inner layer. The inner layer comprises a thermoplastic material, preferably polypropylene (PP), and the outer layer glass fiber reinforced plastic (GRP) on; to ensure the connection between inner layer and outer layer, a lamination layer is arranged. This is particularly useful when the thermal expansion coefficients of the materials used for the inner layer and the outer layer are different. Due to the preferably seamless inner layer, connecting seams are produced only at the beginning or at the end of a pipe section during the assembly of pipe sections.

Furthermore, the invention is based on the basic idea of forming the inner layer, which is decisive for the tightness of the pressure pipeline, with a sufficient layer thickness in order to be able to ensure high quality in the connection of pipe sections, even with minimal axial displacement of the pipe sections relative to one another. The layer thickness of the inner layer (material thickness of the inner tube) and the durability of the penstock is improved. Preferably, a locking device is provided on the outside of the inner layer in order to improve the connection to the outer layer arranged thereon. In particular, by the different coefficients of thermal expansion of the materials used, such as GRP for the outer layer and PP for the inner layer, it can be ensured in addition to the lamination that forces that arise due to the relatively high thermal expansion coefficient of the inner layer, are safely introduced into the GRP structure.

In the following, preferred embodiments will be described with reference to the figures; show it:

Figure 1 is a pressure pipe according to the invention;

Figure 2 shows a layer structure of a pressure pipe according to the invention.

Figure 1 shows a pressure pipe according to the invention with a supporting outer layer 1, which is arranged on an inner tube or an inner layer 2. The outer layer 1 comprises glass fiber reinforced plastic (GRP) and the inner layer 2 comprises a thermoplastic material, preferably polypropylene (PP), on. Between the outer layer 1 and the inner layer 2, a lamination layer 3 is preferably arranged, which is shown in the figures with a dotted line.

The cladding layer 3 preferably comprises glass fibers, particularly preferably glass fiber webs or mats. Depending on the requirements of the materials used for the outer layer 1 and the inner layer 2, preferably E-glass fibers or corrosion-resistant ECR glass fibers are used. Optionally, the lamination layer 3 additionally comprise polyester. By laminating layer 3, a permanent connection between the inner layer 2 and the outer layer 1 is ensured.

In order to ensure a good connection during the assembly of pipe sections, the inner layer 2 is formed with a layer thickness of at least 7 mm, preferably in the range of 10 mm - 20 mm and particularly preferably 15 mm. By means of this layer thickness of the inner layer 2, a secure connection can be produced even with a slight off-axis offset of the tube pieces, for example due to inaccuracy in the assembly, since the area of the collisions encountered or the overlapping area is sufficient. A compound is preferably made by known welding methods.

As shown in FIG. 2, the inner layer 2 preferably has a locking device 4. The locking device 4 is arranged on the outside of the inner layer 1 facing the outer layer 1 in order to improve the connection between outer layer 1 and inner layer 2. In particular, with a temperature-induced change in volume of the inner layer 2 in relation to the outer layer 1, so occurring forces can be conducted into the supporting outer layer 1. By this measure, in addition to the lamination layer 3, it is ensured that the inner layer 2 does not detach from the outer layer 1.

Various expansions of the outer layer 1 and the inner layer 2 are caused by the different temperature coefficients of the materials preferably used and by a delayed heat flow through the layers. For example, if a hot fluid passed through the pipe, the outer layer 1 is only with a certain Time delay relative to the inner layer 2 experience a temperature increase.

The lamination layer 3 is preferably arranged on the entire surface of the outside layer 1 facing the outside of the inner layer 2 and / or the locking device 4. As shown in FIG. 2, the locking device 4 can also have no laminating layer 3 on the side facing the outer layer 1.

The locking device 4 preferably has PP and is particularly preferably formed integrally with the inner layer 2. Alternatively, the locking device 4 can be subsequently arranged on the inner layer 2.

The locking device 4 may have various shapes, as shown by way of example in FIG. The locking device may for example be trapezoidal, cuboid or hemispherical in cross section. Preferably, the locking device 4 extends continuously in a spiral shape in the axial direction on the inner layer 2. Alternatively or additionally, one or more circular or other shaped locking device 4 can be arranged on the inner layer 2.

In the production of a pressure pipe according to the invention, a laminating layer 3 and an outer layer 1 are arranged on an inner layer 2 in this order. The cladding layer 3 is preferably applied to the outside of the inner layer 2 in such a way that at least part of the cladding layer 3 is at least partially in the inner layer

2 invades. Particularly preferred is the lamination layer

3 is heated to the inner layer 2 before application. The inner layer 2 is preferably a seamless tube, preferably with a locking device 4, as above described. With known methods, the outer layer 1 is arranged on the inner layer 2 or the laminating layer 3, for example by winding a glass fiber mat impregnated with synthetic resin or by alternately applying glass fiber mats and synthetic resin. The outer layer 1 is thus firmly connected to the inner layer 2 at least via the laminating layer 3. When the outer layer 1 is applied to the outside of the inner layer 2 or the laminating layer 3, at least by the liquid or deformable synthetic resin of the outer layer 1, a positive connection with the laminating layer 3 or with the inner layer 2 is produced. In particular, when using impregnated with resin glass fiber mats as the outer layer 1, the glass fibers may not completely adapt to the surface of the inner layer 2 and the lamination 3, whereas the liquid or deformable resin all possible spaces between the outer layer 1 and the lamination layer 3 and Inner layer 2 fills. As a result, a positive connection of the inner layer 2 with the outer layer 1 can also be achieved if the cross section of the optional locking device 4 has a shape which tapers at least partially towards the inner layer 2, as shown by way of example in FIG. 2 with a trapezoidal shape. The outer layer 1 forms after curing of the synthetic resin a stable, supporting layer, which gives the inner layer 2 a corresponding rigidity.

Claims

claims

1. pressure pipe with a supporting outer layer (1) and an inner layer (2), wherein the outer layer (1) glass fiber reinforced plastic and the inner layer (2) comprises a thermoplastic material and between the outer layer (1) and the inner layer (2) a laminating layer (3) is.t.

2. Pressure pipe according to claim 1, wherein the inner layer (2) comprises polypropylene.

3. penstock according to claim 1 or 2, wherein the laminating layer (3) comprises glass fibers or a glass fiber polyester composite.

4. Pressure pipeline according to one of the preceding claims, wherein the inner layer (2) has a wall thickness of at least 7 mm, preferably in the range of 10 mm to 20 mm and particularly preferably 15 mm.

5. Pressure pipe according to one of the preceding claims, wherein the inner layer (2) on the outer layer (1) side facing at least one locking device (4).

6. Pressure pipe according to claim 5, wherein the locking device (4) in the axial direction is arranged spirally on the inner layer (2).

7. Pressure pipe according to one of claims 5 or 6, wherein the locking device (4) comprises polypropylene.

8. pressure pipe according to one of claims 5 to 7, wherein the locking device (4) is formed integrally with the inner layer (2).

9. pressure pipe according to one of the preceding claims, wherein the outer layer (1) form-fitting manner with the inner layer

(2) and / or with the lamination layer (3) is arranged.

10. Method for producing a pressure pipeline with the steps:

(a) providing a tube or tube made of a thermoplastic, preferably polypropylene, as an inner tube or inner layer (2),

(b) applying a laminating layer (3) on the outside of the inner layer (2) and

(c) applying an outer layer (1) of glass fiber reinforced plastic on the outside of the lamination layer (3).

11. The method of claim 10, wherein the lamination layer

(3) comprises glass fibers or a glass fiber-polyester composite.

12. The method according to claim 10 or 11, wherein at least a part of the lamination layer (3) at least partially penetrates into the inner layer (2).

13. The method according to any one of claims 10 to 12, wherein the lamination layer (3) for application to the outside of the inner layer (2) is heated.

14. The method according to any one of claims 10 to 13, wherein on the outside of the inner layer (2) prior to the arrangement of the lining layer (3) a locking device (4) is arranged.

15. The method according to any one of claims 10 to 13, wherein the provided inner view light (2) on its outer side a locking device (4).