The pipe joint is filled with air bubbles on site
The interface refers to the parts and the heat preservation process of connecting the ends of the two outer protective pipes with joint sleeves. The thermal insulation patch at this interface is completed by the technicians of the thermal insulation pipe factory and meets the standards and specifications listed in Article 2. The on-site foaming material must be the same as the foaming material of the straight pipe, and PE should be used for foaming. The plug welding seals the foaming hole and the vent hole respectively. Note that the PE plug must be fully welded and welded firmly. The sealing end cover of the foam hole and the vent hole adopts a heat-shrinkable cover. The length of the uninsulated part of the pre-insulated pipe, that is, the free end is 250±10mm.
Pipeline connection interface: polyethylene outer protection with resistance wire on the inner wall should be used, and the field connection should be connected by electrothermal welding. After the external protection patch is connected and passed the 0.02Mpa pressure test, then perform on-site mechanical foaming. After the insulation foaming is completed, the foaming hole and the vent hole are welded and sealed.
After the joint is repaired by thermal fusion welding, the thermoplastic tape is wound and bonded along the welding seam.