CZ35524U1 - Equipment for checking the tightness of plastic pipes - Google Patents

Description

Field of technology

The technical solution relates to a device for checking the tightness of plastic pipes.

State of the art

The materials from which plastic pipes are made have high impermeability and chemical resistance, yet their mechanical failures occur. Damage occurs during their production, during transport, during their installation and subsequent operation. In addition to economic and environmental consequences, such damage can also have health consequences for users. Therefore, the piping needs to be inspected.

A common method of control is to use a flow and pressure measurement system. The basic physical principles for determining flows are the mean flow velocities, or determining the volume of fluid flowed in a certain time interval. Fluctuations in pressures and flow rates in the network are a good identification factor according to which a possible fault in the network can be inferred.

It is possible to check for leaks and identify faults from the outside, ie externally, or from inside the pipe, ie internally. The liquid that escapes from the pipe creates noise, sound waves. We divide it into internal and external. Internal noise is sound waves that propagate through the walls of a pipe and the liquid inside the pipe. External noise arises at the site of the leak and spreads through the soil. The speed of sound propagation and the distance to which the sound acts significantly affects the pipe material. The more flexible the material, the smaller the distance. As a result, the failure on the steel pipe will be better located than on the plastic pipe, which is made of a more flexible material.

Soil microphones, which monitor external noise, are a relatively accurate method of locating fluid leaks, but this method is time consuming. To external methods monitoring leaks from the outside of the pipeline, it is also possible to assign methods for measuring the composition of the gas that is pumped into the pipeline.

The gas used is a mixture consisting of 5% hydrogen and 95% nitrogen and is non-flammable, non-toxic and non-corrosive (according to ISO 10156). Hydrogen is the lightest gas and has a very low viscosity, so it spreads easily. Thanks to this, it is able to penetrate concrete, paving, asphalt and it is possible to locate it relatively accurately.

The internal methods, ie the methods for monitoring leaks from inside the pipeline, include the acoustic correlation method, which works on the principle of comparing the noise detected at two places in the pipeline (hydrant, slide valve, etc.). Sensors are placed in these places and then the detected values are evaluated.

Internal methods include methods in which the acoustic sensor moves directly inside the pipe, for example in the form of a self-floating sphere (SmartBall® method) or a hydrophone connected via a water-pressure cable acting on a parachute connected to the front of the sensor ( Sahara® system). These devices record and accurately locate any leakage on the pipeline.

An overview of existing technologies shows that while companies have been improving their existing facilities in recent years, no new technology has emerged to be deployed on a mass scale.

-1 CZ 35524 UI

Due to the fact that plastic pipes (PEHD, PVC, ...) are increasingly used, which are more flexible and therefore dampen noise faster, the use of fault location methods that work with the sound signal is less efficient.

Plastic pipes are electrically non-conductive, so if they are stored in a conductive environment, electrical methods can be used to locate leaks.

The aim of the technical solution is to design such a device for checking the tightness of the pipeline, which would allow to effectively detect the location of the leak.

The essence of the technical solution

This object is achieved by a device for checking the tightness of plastic pipes, according to a technical solution, the essence of which consists in a source of electric field connected on the one hand to a saturating positive electrode which is arranged inside the controlled plastic pipe and on the other hand to a saturating negative electrode which is arranged outside the inside of the inspected plastic pipe. Both saturating electrodes are connected to the monitoring unit.

The pipe leak tester allows you to effectively detect the location of the leak.

According to a preferred embodiment, the negative electrode is placed in the ground of the inspected plastic pipe, wherein a plurality of measuring electrodes are arranged at regular intervals below the inspected plastic pipe, which are connected at regular intervals by an insulated conductor connected to the monitoring unit. arranged measuring device with interconnection relay for sequential interconnection of pairs of adjacent measuring electrodes.

Another advantageous embodiment is suitable for multilayer plastic pipes with an electrically conductive inner layer. The saturating negative electrode is connected to the electrically conductive inner layer, the saturating positive electrode is arranged inside the inspected plastic pipe, and both saturating electrodes are connected to the monitoring unit.

Clarification of drawings

The technical solution will be described in more detail with links to the figures, which show:

Fig. 1 - a first embodiment of a device for checking the tightness of a plastic pipe laid underground;

Fig. 2 is a diagram of the use of the device of Fig. 1 for electrokinetic decontamination in the event of damage to pipelines with contaminated liquid; and FIG. 3 is an example of an embodiment of a device for checking the tightness of a multilayer plastic pipe having an electrically conductive inner layer.

Examples of technical solutions

Fig. 1 shows a first embodiment of a device for checking the tightness of a plastic pipe 1 which is laid underground. The device comprises an electric field source 6, connected on the one hand to a saturating positive electrode 5, which is arranged inside the inspected plastic pipe 1, and on the other hand to a saturating negative electrode 7, which is grounded from the outside to the inside of the inspected.

- 2 EN 35524 Plastic pipe UI E Both electrodes 5, 7 are connected to a monitoring unit 4, in which a measuring device 3 with a connecting relay is arranged.

Just below the inspected plastic pipe 1, a number of measuring electrodes 2 are arranged at regular intervals in the ground parallel to the axis of the pipe 1. In the described exemplary embodiment, the measuring electrodes 2 are arranged at 5 m intervals. Smaller spacings, ie a larger number of measuring electrodes 2, are used in places with a higher risk of damage to the pipeline 1, eg in areas with the possibility of landslides, subsidence, etc.

Each of the measuring electrodes 2 is an insulated conductor 12, with protective insulation up to 1000 V, connected to the monitoring unit 4.

The saturating circuit, formed by an electric field source 6 and a pair of saturating electrodes 5,7, generates an electric field, the magnitude and intensity of which, depending on the size and type of the pipe 1, range from 1 to 1000 V and 0.1 mA to 1 A.

The pairs of adjacent measuring electrodes 2 are successively connected to the measuring circuit by means of a measuring device 3 with an interconnection relay in the monitoring unit 4.

The measuring device 3 with the connection relay in the monitoring unit 4 measures the distribution of electric potentials in the range of 0.1 mV to 1 V, on the measuring electrodes 2 in an artificial electric field, the anomalies in the artificial electric field indicating a leak in the controlled plastic pipe 1.

Fig. 2 schematically shows an example of the use of the device according to the technical solution for performing electrokinetic decontamination in the event that the pipeline 1 with contaminated liquid is damaged.

The arrangement of the saturating electrodes 5,7 can cause electromigration inside the pipe 1 by the action of a direct current electric field. Electromigration acts on contaminants in the form of positive ions 8. Positive ions 8 are attracted in the electric field by negative ions 9 against the direction of leakage of the contaminant 10 from the pipe 1 and are thus retained in the damage area until the pipe 1 is repaired.

Fig. 3 schematically shows an example of the application of the device according to the technical solution to a multilayer plastic pipe 1 having an electrically conductive inner layer 11. In the described exemplary embodiment, the electrically conductive inner layer 11 is an aluminum insert. The saturating negative electrode 7 is connected to the electrically conductive inner layer 11 of the pipe E. The saturating positive electrode 5 is immersed inside the pipe 1.

The saturating electrodes 5, 7 are connected to the electric field source 6 and to the monitoring unit 4.

If line 1 is intact, then the electric current in the device is zero. In the event of damage to the electrically conductive inner layer 11 of the pipe 1, a direct current begins to flow through the circuit, which the monitoring unit 4 immediately detects and sends an optical / acoustic signal. Thus, the tightness of the pipe 1 can be permanently checked independently of the environment in which the pipe 1 is located, for example also in electrically non-conductive polystyrene, in air, etc.

Claims (3)

PROTECTION REQUIREMENTS Device for checking the tightness of a plastic pipe (1), characterized in that it comprises an electric field source (6) connected on the one hand to a saturating positive electrode (5) which is arranged inside the plastic pipe (1) to be inspected and on the other hand a negative electrode (7) which is arranged outside the inside of the inspected plastic pipe (1), the two saturating electrodes (5, 7) being connected to the monitoring unit (4). Plastic pipe leak tester according to Claim 1, characterized in that the negative electrode (7) is arranged in the ground at the inspected plastic pipe (1) and is parallel to the axis of the pipe (1) below the inspected plastic pipe (1). a plurality of measuring electrodes (2) are arranged at regular intervals, which are connected by an insulated conductor (12) which is connected to the monitoring unit (4), while a measuring device (3) with a connecting relay for sequential connection is arranged in the monitoring unit (4). pairs of adjacent measuring electrodes (2). Plastic pipe leak tester according to claim 1, characterized in that the controlled plastic pipe (1) is multilayer with an electrically conductive inner layer (11), the saturating negative electrode (7) being connected to the electrically conductive inner layer (11). .