Carrying out a zero cycle of work during the construction of an object or digging trenches for technological pipelines, cables requires knowledge of the specific location of the possible passage through the site of previously laid engineering communications.
The task of finding a water pipe (underground communications) underground, an electric or stranded telephone cable and not damaging them when working with an excavator or bulldozer is quite feasible if you approach the search system correctly and competently.
This task must be solved before the start of earthworks on the site in order to prevent the risk of damage to communications, fines and material costs for restoration, covering the damage caused.
Administrative ways to search for water pipes underground
When the site for the construction of an object is located within the boundaries of a settlement, it is likely that communications of the central hot or cold water supply, sewerage, electric or telephone cable are laid through it. The laying is done in the area of the red line along the street, but there is a trace in the most incredible directions.
Officially laid communications are registered in the departments of architecture and urban planning, applied to the plans of technical documentation with precise reference to the red lines of the adjacent areas. It is recommended that you first contact these organizations for information.
It happens that data on the laying of underground utilities are not reported to supervisory organizations. Contact the appropriate organizations before starting excavation work. Take information about the presence of communications laid along the construction site, if any, the depth of laying, accurate tracing with reference.
This will allow safe excavation and remove liability in the event of damage to an unspecified pipeline or cable. When a pipe with an unauthorized tie-in passes through the site, the owner of the tie-in is responsible for the damage.
The search for water pipes underground is independently carried out by the following methods:
- With the involvement of a specialized organization;
- With the help of technical means purchased independently or rented;
- Independent search with the help of the simplest frame.
Involvement of a specialized organization
To obtain the most effective result in finding a pipe for a water supply network located underground, the best option is to entrust the work to a specialized organization. The professional actions of the company’s workers, the use of modern control and measuring equipment will reduce to zero emergency situations during earthworks with the help of mechanisms.
Turning to professionals has a number of undeniable advantages:
Technologies and methods of independent search for underground utilities
Underground utilities that may be located on the site include:
- Metal pipes for hot or cold water supply, heat supply, cast-iron sewer pipes, power supply cables, telephone lines;
- Water pipes that do not conduct electricity — plastic, polyethylene, polypropylene, made from modern innovative materials.
Which pipe to use for laying a pipeline underground depends on the pressure in the network, the condition of the soil, the level of groundwater, aggressiveness and other factors. Therefore, the search is organized by methods using appropriate technological equipment.
Metal detector application
Metal pipes located at a depth of 1.5 meters are easiest to look for with a conventional metal detector. At the same time, the thermal insulation of water pipes in the ground does not affect the result of the search. Metal detectors allow you to get accurate results without significant material costs, on your own.
Metal detectors for sale are categorized as:
- for beginners;
- middle class;
The cost of products ranges from 5.5–125 thousand rubles. To search for a pipeline, it is recommended to use a medium-class metal detector. It is not worth buying a device for one-time use, rent it or from a friend.
Special equipment and methods of working with it
To accurately determine the location of various communications underground, special equipment is used that is designed specifically for performing such tasks. Types, a line of such equipment is produced from simple devices to stations that allow you to receive data, process information, and transmit via satellite over a network.
The equipment is expensive and is used by companies specializing in such studies. Search equipment includes:
- georadar (Geomax);
- cable locators;
- route finders;
- trace stations;
- tape and marker finders.
The choice of search method and equipment depends on the type of communications, the materials from which the pipes are made, the availability of one of the ends of the pipe (cable) or the lack of data on the presence and routing of cable lines and pipelines.
The principle of operation of equipment for monitoring the trace and the state of communications is based on capturing by a heterodyne receiver an electromagnetic induction field that is formed around a metal object in the ground or directly by a generator. This method is called inductive.
Methods for searching for an inductive, electromagnetic field created around pipes or cables:
- Contact. This method includes active methods of current induction using a generator — direct connection (galvanic) or using a ring induction clip. In both cases, direct access to one end of the water pipe or cable must be provided in advance to determine the route. This is the most efficient and accurate way;
- Active contactless. In this case, the generator creates an electromagnetic field using a built-in induction antenna over the place of the proposed pipeline passage;
- Passive. Here the generator is not used. A pipeline or cable is found by induced electromagnetic fields. The method is used when there is no data on the presence and traceology of communications. In this variant, the accuracy and search efficiency are minimal.
The set of equipment consists of the following elements:
- heterodyne receiver;
- Set of cables for connecting power, grounding, direct connection to the pipeline with clamps or an induction ring clip.
Generator — a device that generates a signal of one of the discrete set of frequencies set by the operator depending on the state of the search object. To determine the trace of an electrical cable under voltage, the frequency is set to 50 Hz, to search for pipes with cathodic protection — 100 Hz.
The generator is designed for forced current excitation with direct connection (galvanic) to the test pipe or inductive. When current passes around a cable or pipe, an electromagnetic field of a given frequency is artificially created. The electromagnetic field signal is received by the detector with a pulse or induction antenna.
In the case when there is no direct access to a water pipe or cable cores without voltage, a forced signal is given to them by a generator installed above the objects through a built-in induction antenna.
For passive search, the generator is not used.
With proper use of the devices of the kit, manufacturers guarantee a service life of up to 5 years.
The receiver is the most important element of the kit. The receiver receives electromagnetic field signals from underground utilities generated by a generator or natural from other emitters. After switching on, match the receiver-generator pair for correct operation on the operating frequency and signal processing method.
The receiver receives a signal with two antennas — pulse and induction. The signal is processed by the program, if the data from both antennas match, the information is displayed. The amount of data displayed on the display, the location and configuration varies with different types of equipment, the number of available functions, the manufacturer’s company.
Below the display are the setting and control keys. Here the receiver is turned on, the sound level in the headphones is set, the display screen resolution is set, the frequency is set, the operating mode is set. Separate keys call up the menu and select items. In addition to information about the trace, the screen shows how deep the pipe is buried, but only at the maximum signal (the distance is indicated to the center of the object).
The use of the locator, connection, purpose of each key, display indications, discrete frequency settings and the user menu are described in the attached documentation or on the body of the receiver, generator.
Carefully familiarize yourself with the possible functions of the device, the order of change and display.
See the video for instructions on setting up the Ridgit locator as an example. It tells how to work correctly and correctly with devices, possible functions.
Finding plumbing plastic pipes
When searching for plastic, polypropylene water pipes, the induction method is not suitable — there is no electromagnetic field around the pipe and there is no possibility of using a generator.
To detect the position of such non-conductive pipes, the method of laying a metal cable, probe or float inside the pipe is used. When connected to a generator, these elements emit a signal at a given frequency. The direction to the probe is determined by raising the receiver antenna at an angle with rotation until a stable maximum signal is obtained.
Using the frame to search the ground for metal and plastic pipes, electrical, telephone or fiber optic cable gives results without the material costs of acquiring expensive equipment. The nature of this phenomenon from the point of view of science and medicine is not explained, it occurs at the level of human intuition.
Not everyone is given to work with a frame, do not be upset if it does not work out.
- Take two even aluminum wires 35–40 centimeters long. Bend them with the letter “G” so that one end is no less than the width of the palm. It is permissible to use metal wire or electrodes without a sheath with a diameter of not more than 3 mm. It is important that the frame is light;
- Take the wires in your hands, you don’t need to clench your fists, the effort is only to hold the frame;
- Bend your arms at the elbows, with the long ends of the frame placed forward, parallel to each other and in relation to the ground, keep the distance between them 15–20 centimeters;
- Find the area where the pipe or cable runs underground. Move 2–3 meters away from the axis of the pipeline, take the frame as in paragraph 3, slowly approach the axis of the underground pipeline. In this case, do not clamp the wires in your fists. When approaching the axis, the wires cross. Above the axis of the pipe, the wires will finally cross and stand parallel to the axis. Further movement will cause the wires to return to their original position;
- Regardless of whether it worked or not, do this 5–6 times. Pay attention to the distance to the axis at the beginning of the crossing of the wires, at the exit. An experienced practitioner determines the depth of the pipeline or cable from these distances.
By combining the methods described above, active or abandoned communications are found with high accuracy, regardless of the depth of the location. This will avoid complications during the zero cycle work at the construction site or find a pipe or cable rupture.