1.1 both sides of the operation pit shall be provided with a safe passage for convenience up and down. If the soil quality of the operation pit is unstable, it shall prevent the operation pit from collapsing
Measures: precipitation measures should be taken in areas with higher groundwater level.
1.2 the axial length of the operation pit shall be extended by 1 meter or more at each end of the section to be repaired, and the width shall be at least 1.5 meters from each side of the outer diameter of the pipeline
Meters and above, the operation pit is not less than 0.5 meters from the bottom of the pipeline, and smooth for the installation of equipment and personnel operation.
2. Operation platform construction
2.1 in case of above-ground pipeline construction, the operation platform shall be built when the top of the pipeline is 1.3 meters above the ground.
2.2 the operation platform shall be firmly built, the size requirement shall not be less than the size requirement of the operation pit, and there shall be enough operation space, as well as guardrail and
Up and down the ladder.
3. Remove the anti-corrosion layer of the pipeline in the construction section.
4. Check the defect points for external defects, mark the location, size, shape and other parameters of the defect points, record and take photos.
Confirmed by party a.
5. All the pipelines in the sleeve coating section shall be cleaned with xylene, and the surface shall be completely polished. The grinding depth shall not exceed 0.3mm
Grinding out the metal color, polishing to ST3.
6. Reinforce and repair the defect points with quick steel;
7. Install the sleeve
7.1 before installation, there shall be no dirt, dirt or other sundries on the surface of the inspection sleeve and repair section.
7.2 place the sleeve bottom plate at the bottom of the pipeline, and place the sleeve top plate on the pipeline
When the upper plate is about 100mm, install the rectangular flange tetrafluoride gasket and continue to raise the bottom plate to the position where the connecting bolts can be installed
Install the connecting bolt after setting and aligning.
7.3 before the pre-tightening of the connecting bolt, adjust the inner diameter of the sleeve and the concentricity of the upper and lower plates shall not be greater than 1.5mm, and pre-tighten the bolt.
7.4 bolt pre-tightening installation from the middle to both sides of the pre-tightening, pre-tightening force according to the specifications of the bolt, material and performance grade.
8. Install the sleeve end face adjustment bolts, and adjust the distance between the inside diameter of the sleeve and the outside diameter of the pipeline by 10-15mm
After finishing, seal the gap at both ends with quick steel.
9. After both ends are sealed, wait for curing for about 10-15 minutes. After curing, remove all the adjusting bolts and install the top wire of the same specification.
10. Connect the glue injector and epoxy sleeve bottom plate to the injection hole and wait for the injection of glue. Connect the epoxy resin glue with the curing agent according to the weight
The mix proportion, the adhesive and curing agent with stir bar beaten, control time not more than 1 minute, put them into the sleeve inside, when the top of the sleeve vent overflow resin, install the corresponding top silk, until all the vent overflow to fill the sign and install the top silk, stop injection, injection valve at the bottom of the screw is installed, remove the note binder.
Note: the temperature below 20 degrees, epoxy resin adhesive heating 35 to 55 degrees, it is advisable to good liquidity, easy mixing and injection, injection to ensure the continuity of injection, rubber injection machine of absorb when warranted the absence of air suction, injection, ensure all note glue in epoxy resin injection, as more and more into the resin, injection plastic injection with resistance, at this time to extend the time of injection, ensure all resin injection.
11. Epoxy sleeve anti-corrosion treatment, anti-corrosion materials can choose viscoelastic paste, viscoelastic tape, glass silk cloth, asphalt paint, cold wrap
Belt, etc., or according to the requirements of party a, anti-corrosion test according to the requirements of party a, after qualified backfill.
Note: the resin mixed with the curing agent can be evenly coated on the sleeve before being used up
Silk fabric lap third winding 2 to 3 layers, in the selection of other anticorrosive materials.