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Requirements of heat shrink tape in steel pipe joint construction
- Aug 13, 2018 -

The heat shrink tape can be used for anticorrosion and repair work of pipes such as water supply and drainage pipes and elbows. When it is used in the joint repair of steel pipes, in order to ensure the good effect of the mouth filling, it is necessary to meet the relevant construction requirements.

Before the steel pipe is filled, the joints must be cleaned, and the ring welds and their nearby burrs, welding slag, dirt, oil and their debris should be cleaned up. The surface of the joint part shall be derusted, and the surface derusting treatment quality shall reach the Sa2.5~Sa3.0 grade specified in GB/8923 for the surface corrosion grade and derusting grade of the steel before painting. It can be rusted by sandblasting or electric tools. The polyethylene layer of the joint lap joint shall be ground to a rough surface, and the end portion shall be treated with a groove, and the end of the slope shall be treated with a groove, and the slope angle shall be no more than 30 degrees. The fill portion is then preheated with a flame heater. The width of the anti-corrosion heat shrink tape and the polyethylene anti-corrosion layer shall not be less than 100 mm. If the humidity is greater than 85% or it is raining or snowy, stop construction.

Quality inspection after construction:

The quality inspection of the heat shrink tape or the wrapping tape should be checked one by one, and the surface should be smooth and flat, without wrinkles and bubbles. The corners of the two ends are closely attached to the heat shrink sleeve, and there is no gap, and there is no carbonization on the surface. The hot-shrink tape should have a uniform overflow of the hot-melt adhesive in the circumferential direction, and the spark leak detector should be used to check the pinholes one by one.

After the heat shrinkage belt is applied to the construction of the steel pipe joints, this series of construction inspections can meet the requirements and complete the repair work. The inspection work after the repair is very important for the later use, so we must pay attention to it.