Measuring and testing – With fluid pressure – Leakage
Patent
1990-12-10
1992-08-25
Williams, Hezron E.
Measuring and testing
With fluid pressure
Leakage
73 405R, 174 11R, G01M 338
Patent
active
051408473
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
The invention concerns a cable for detecting location of liquids, whereby, when liquid enters, a physical change occurs in the cable structure at the leakage point, which change is measured and evaluated.
BACKGROUND OF THE INVENTION
Cables for detecting location of liquids are used e.g. in the monitoring of liquids in storage and transport, which might have harmful effects on the environment, particularly on air, soil, and ground water. This includes e.g. pipelines or tanks for oils, propellants, and chemicals of various kinds. Cables for this purpose are known, in which the electrical characteristics change in the area of the liquids to be located. These changes are mechanically detected and serve to define the position of the leakage.
The previously known measurement procedures and cables are expensive and have limited usefulness due to the length of application. Detectability with aid of electrical procedures is good, and the determination of the leakage location is possible with simple means. However, the known procedures of this kind are susceptible, particularly to electromagnetic disturbances. In addition, the possible length is strictly limited by the transversal conductibility of the insulation materials. With respect to location of hydro-carbonbased liquids, it is possible to locate these as well by means of changes of the dielectric characteristics of conductors at the location of the leakage. However, there are problems due to the fact that the liquids to be detected are very similar to the insulation materials particularly with respect to the dielectric characteristics. Reliable location is thus possible only with great wetting lengths or over small lengths of measurement cables.
The purpose of the invention is to provide a cable for detecting location of liquids, which cable rapidly and reliably indicates a presence of liquids of varying kinds and thereby allows a precise location of the leakage over a significantly greater distance than has hitherto been possible.
SUMMARY OF THE INVENTION
In accordance with this invention, these requirements are fulfilled with a cable for detecting location of liquids, in which a physical change of the cable structure at the leakage point occurs in the presence of liquid, which change is detected. This is accomplished by a cable having a core element which is sensitive to pulling or bending, a first sheathing of material that swells in the liquid to be detected, and a second sheathing fixed on the first sheathing, consisting of a plaiting of high stability yarn With low stretching characteristics, and with a plaiting angle greater or smaller than the so-called neutral angle.
Further, a third sheathing which is of a material which is of a structure permeable by the liquid to be detected may serve as protection against external mechanical effects. In order to assure a reliable indication, the material of the third protective sheathing can go into solution with the liquid to be detected.
Further, in order to reliably exclude the possibility of radial penetration of the swelling material through the plaiting, particularly in the case of swelling materials with low viscosity, an intermediate layer can be provided between the first and second sheathing, which layer, though permeable to the liquid to be detected, nevertheless prevents the swelling material from penetrating the plaiting. This intermediate layer may consist e.g. of a high-strength, absorbent fibrous web and may be applied in the form of strips.
Further, according to the type of liquid to be located, the swelling agent may be a polymer, an elastomer, particularly a silicone, or a mixture of these, or a mixture of materials with at least a portion of these materials. Particularly, the swelling material may be extruded onto the surface, or applied in the form of strips, particularly in the form of a swelling fibrous web or a swelling powder, introduced on or in a strip. In the case of aqueous liquids to be located, a cellulose-based material is appropriate.
Further, the pla
REFERENCES:
patent: 4570477 (1986-02-01), Sugibuchi
patent: 4710353 (1987-12-01), Tanaka et al.
patent: 4926165 (1990-05-01), Lahlouth et al.
Diegmann Wolfgang
Tausch Norbert
Kabelwerke Reinshagen GmbH
Roskos Joseph W.
Williams Hezron E.
LandOfFree
Cable for detecting location of liquids does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cable for detecting location of liquids, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cable for detecting location of liquids will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-377364