CN85107620A

CN85107620A - Method for installing a testing device during the laying of a thermally insulated pipeline and such a testing device

Info

Publication number: CN85107620A
Application number: CN85107620A
Authority: CN
Inventors: 哈斯·埃里克森
Original assignee: Nitto Scandinavia AB
Current assignee: Nitto Scandinavia AB
Priority date: 1985-10-16
Filing date: 1985-10-16
Publication date: 1987-05-27

Abstract

The device for indicating water leakage in a thermally insulated line consists of a pair of spaced electrical conductors (5) and a supporting carrier. The electrical conductor (5) is arranged in a strip-like covering comprising two surface layers (4, 6) of an electrically insulating material, at least one of the surface layers (6) being liquid-absorbing and/or liquid-soluble. The surface layers (4, 6) are interconnected by an adhesive layer (8). An outer surface of the cover has a second adhesive layer (9) for adhering to the pipeline (1), the second adhesive layer being covered by a protective film when the detection device is not in use.

Description

The method of installation and measuring device and this pick-up unit thereof when the laying heat insulation pipeline

In order to detect the infiltration of steam or liquid by the electric transition between the conductor, a kind of method that the pick-up unit of electric conductor form is installed when the laying heat insulation pipeline.Conductor is positioned to a distance each other, and be actually be parallel to each other and with pipeline be electrical isolation, be exposed to steam or the liquid that passes thermal insulation layer at the pipeline upper conductor.

Situation for indication heat insulation pipeline, the hot pipeline of certain for example, people are placed on two copper conductors usually in the exhausted body of the edge of steel pipe, water is penetrated in the exhausted body of edge and leaks into from ground or from pipeline, its sign is by the resistance between copper conductor and the pipe being measured acquisition, by suitable detection method people the leak position that measures being accurate to roughly within 1 meter.

In a class warning system, copper conductor is the other end that is applied to pipe from an end of pipe between inner steel pipe and outer plastic pipe.Before on the steel pipe, copper conductor is exactly stretching in insulating material (normally Polyurethane) foaming.When the sub-alternating temperature of steel pipe and when expanding, a kind of danger is arranged, promptly copper conductor is stretched so that breaks, because middle insulator, the increase of the temperature of copper conductor is negligible.

When copper conductor does not stretch,, there is bending to allow in order to reduce thermal expansion effects.On the one hand because tube bending because the masterpiece that the pipe foaming causes is used on the copper conductor, makes conductor not wait the distance of copper pipe on the other hand.

Furtherly, when utilizing the Polyurethane edge, form high-density layer, and be difficult to by water decomposition near the copper conductor place.This causes before the warning system action, and big water gaging flows along pipeline, and this is undesirable.

Alarm logging is by sending a pulse along copper conductor, and this pulse is returned via a possible leakage and steel pipe.Burst length can be transformed into distance.If conductor changes the distance of steel pipe, this is the situation that this warning system often has, and this variation can cause the interference to instrument.

Another kind of warning system is made up of the band of polyamine fat, belt is wrapped on the pipe before forming in foaming on the pipe at insulator, copper conductor is arranged in the groove in the band, this system can stop the infiltration of polyamine insulator and fill up in the belt and all volumes on every side, the result, when having leakage, because not significantly indication will cause in the expansion of para tape environment temperature very fast.

A warning device knows that by SE-B-375-395 this warning device comprises the hygrosensor of a textile tapes form, and electrical lead is woven in the textile tapes the inside, and is connected to the warning part.Temperature is surveyed textile tapes and is arranged on floor carpet under, and the danger of soaking is arranged there.

The objective of the invention is to find a kind of method, according to the method:

(a) steel pipe there is a constant distance.

(b) no tensile stress acts on the copper conductor, so conductor can not rupture.

(c) copper conductor is embedded in the expanded material, can not change its temperature detection performance.

(d) the product that obtains to compare with the enabled production on other markets be cheap.

(e) install in warning system, can quite save time.

According to the present invention, in fact the electric conductor on the strike is being sealed by the strip coverture, and this coverture has two superficial layers that formed by insulating material, and one of them can absorb liquid and maybe can be dissolved in liquid at least.This superficial layer is connected with an adhesive coating, and the one mask has that the coverture of an adhesive coating is sticking to be pressed on the surface of pipeline, then, adds thermal insulation layer.

Hereinafter with reference to two specific embodiments, as shown in drawings, the present invention is described in more detail.

Fig. 1 has shown the sketch section of the heat insulation pipe of installing with sniffer of the present invention.

Fig. 2-4 has shown the vast scale section according to three different vicissitudinous sniffers of the present invention.

According to the specific embodiment that shows in Fig. 1, innermost is steel pipe 1, is thermal insulation layer 2 in its outside, for example is made of polyamine fat, and outermost layer is a plastic pipe.

Directly placing an electrical insulation tape 4 and a pair of (in the time will using a signal transmssion line or three) electric conductor 5 in the steel pipe outside, for example making of copper, this conductor is fixed on the electrical insulation tape 4 as water soluble band 6 by the water soluble adhesive coating.When water permeated, water soluble ungirded and 6 is decomposed, and warning system provides a signal simultaneously.

In the specific embodiment that Fig. 2 shows, electric conductor 5 is set in the strip coverture, and this coverture has two electrical isolation

superficial layers

4 and 6, and superficial layer 6 is that the liquid soluble material constitutes at least, as the textile material cotton.

Superficial layer

4 and 6 bands by adhesive coating 8 are interconnecting.Adhesive coating 8 is between electric conductor 5 or the outside.Superficial layer 4 is to be covered with by diaphragm 10, and when this device was used on the pipeline 1, diaphragm was taken down.

Shown specific embodiment is different from the specific embodiment in Fig. 2 among Fig. 3.In Fig. 3, the adhesive coating between the

superficial layer

4 and 6 also is covered with electric conductor 5, if adhesive coating 8 is not that liquid is soluble, has a perforation 11 on electric conductor 5, allows the liquid infiltration.Adhesive coating 8 preferably is made up of the adhesive film that is referred to as heat fusing, but also can be the material of water dissolvable, need not to bore a hole 11 in the case.

In the specific embodiment that shows in Fig. 4, additional electric conductor 7 is imbedded in the adhesive coating 9, in the case, when pipe 1 by non electrically conductive material for example plastics form, electric conductor 7 uses as one zero conductor.Surface facing to the zero conductor 7 of pipe 1 is exposed, and does not promptly have adhesive coating 9 to be covered with.

Device according to the present invention has many advantages:

A) be easy to directly be attached on the interior pipeline;

B) report to the police for measuring, electrical impedance is constant, because the resistance of electrical insulation tape is constant.

C) because system does not have cavity, current lose and are restricted longitudinally.

D) water dissolvable or water sorbent surface layer have avoided polyurethane to form high-density layer at the copper body.

E) danger of stretching copper conductor is eliminated, because their temperature is the temperature along with pipe, and pipe allows to dwindle the area of copper conductor.

Certainly, the restriction of the specific embodiment that the present invention is not provided, its protection domain is determined by following claim.

Claims

1, for surveys the infiltration of steam or liquid by the electric transition between the conductor, when the laying heat insulation pipeline, a kind of method of the pick-up unit of electric conductor form is installed, conductor be positioned to a distance is arranged each other and also be actually be parallel to each other and with pipeline be electrical isolation, be exposed to steam or liquid at pipeline line upper conductor by thermal insulation layer; The characteristics of this method are that electric conductor vertically is to be sealed by the strip coverture along it, and this coverture has two superficial layers (4,6) that are made of electrically insulating material, and one of them can absorb liquid and maybe can be dissolved in liquid at least.This obducent outside surface has an adhesive coating (8), and sticking being pressed on the surface of pipeline then, adds thermal insulation layer thereon again.

2; according to claim 1; wherein said pick-up unit includes the carrier of the support electric conductor that is used to survey steam or liquid infiltration in the thermal insulation layer of closing pipe line; above-mentioned electric conductor is arranged to such an extent that a distance arranged each other; its characteristics are that electric conductor (5) is arranged in the strip coverture the inside that includes two superficial layers that are made of electrically insulating material; one of them superficial layer can absorb liquid and/or be dissolvable in water liquid; superficial layer (4; 6) interconnecting by adhesive coating (8); one second this adhesive coating of adhesive coating is arranged on the obducent outside surface when pick-up unit does not use, cover by a diaphragm (10).

3, be that according to the characteristics of the described sniffer of claim 2 adhesive coating (8) between the superficial layer (4,6) is made up of the vertical band between electric conductor (5).

4, according to claim 2, wherein the characteristics of sniffer are that the adhesive coating between the superficial layer (4,6) is made up of the liquid soluble material.

5, according to claim 2, wherein the characteristics of sniffer are that superficial layer (4,6) is made up of membrana perforata, preferably are made up of the adhesive film of heat fusing.

6, according to a top claim, wherein the characteristics of sniffer are that another electric conductor (7) is to be embedded on second adhesive coating (9) in the obducent outside, and above-mentioned electric conductor plays zero conductor effect, and it is carried obducent side and is exposing.