Construction

The cable warning tape is composed of a bottom film, a surface film and aluminum foil. The bottom film is firmly combined with the surface film and the aluminum foil, and is integrally embossed.

The trace cable warning tape is printed with eye-catching and permanent warning words, without fading or discoloration.

Physical Properties

There is no joint in each roll of trace cable warning tape.

The peel strength of the two layers of plastic film of the trace cable warning tape should be greater than 0.10N/mm (tensile speed 25mm/min).

Each roll of trace cable warning tape should be electrically conductive, and the resistance is less than 20Ω/100m (detected by an ohmmeter).

The elongation rate of the trace cable warning tape is ≥25%.

Installation

The trace cable warning tape is laid at 300 - 500mm above the pipe top (to ensure that the pipeline will not be damaged when the trace tape is excavated during construction), but it must not be laid in the subgrade or pavement.

For pipelines with a diameter of not more than 400mm, one trace cable warning tape can be laid above; for pipelines larger than 400mm, two trace cable warning tapes with a horizontal clear distance of 100 - 200mm should be laid in parallel directly above the pipeline.

During the laying process, the connection of two trace cable warning tapes should be overlapped by about 1 meter. At the overlap, peel off the PE film on the aluminum foil side to expose the aluminum foil, so that the aluminum foils of the two trace tapes are in full contact. Then, use plastic tape to tightly wrap the overlapped part as a whole to ensure firm bonding and conductivity after being energized.

At the end of the PE pipe, if the trace tape is not led out of the ground, the trace tape should be peeled off for 50 centimeters long to allow the aluminum foil to fully contact the ground. The aluminum foil and the ground form a circuit to reduce contact resistance and improve detection quality.

During the laying process, a signal source well can be set up to lead out the trace tape and leave it in the well for 1 meter for use during detection.

The trace tape is integrally embossed and placed and transported in rolls. After the trace tape is unrolled, it will not be flat. During construction, open the trace tape for 4 - 5 meters. Two people hold the two ends with their hands and pull it flat hard. After releasing their hands, the trace tape will be flat. Then lay it.

The locally over-excavated part should be backfilled and compacted. When there is no groundwater at the bottom of the ditch, if the over-excavation is within 0.15m, the original soil can be used for backfilling; if the over-excavation is more than 0.15m, lime soil can be used for treatment. When there is groundwater or a large amount of water at the bottom of the ditch, graded sand and gravel or natural sand should be used to backfill to the elevation. After the over-excavated part is backfilled, it should be compacted, and its compactness should be close to that of the natural soil of the original foundation.

In collapsible loess areas, it is not suitable to construct during the rainy season. Or during construction, the accumulated water in the ditch should be effectively drained. When excavating, a soil layer with a thickness of 0.03 - 0.06m should be reserved at the bottom of the ditch for compaction treatment.

When there are abandoned structures, hard stones, wood, garbage and other sundries at the bottom of the ditch, they must be removed. A layer of sand or plain soil with a thickness of not less than 0.15m should be laid, leveled, compacted and designed elevation.

Frozen soil, garbage, wood and soft substances shall not be used for backfilling. The backfill soil on both sides of the pipeline and within 0.5m above the pipe top shall not contain debris such as gravel and bricks, and lime soil shall not be used for backfilling. The stones in the backfill soil more than 0.5m above the pipe top shall not be more than 10%, and the diameter shall not be greater than 0.1m and be evenly distributed.

The backfill soil should be compacted in layers. The loose paving thickness of each layer should be 0.2 - 0.3m. The backfill soil on both sides of the pipeline and within 0.5m above the pipe top must be compacted manually. The backfill soil more than 0.5m above the pipe top can be compacted by small machinery. The loose paving thickness of each layer should be 0.25 - 0.4m.

Along the line where the gas pipeline is buried, warning tapes should be laid continuously. Before laying the warning tape, the laying surface should be compacted and laid flat directly above the pipeline. The distance from the pipe top should be 0.3 - 0.5m, but it must not be laid in the subgrade or pavement.