Views:4593 Author:Site Editor Publish Time: 2020-06-09 Origin:Site
In addition to the characteristics of light weight, corrosion resistance, non-scaling, and long service life of PPR pipes, it also has the characteristics of non-toxic, hygienic, thermal insulation, energy saving, long service life, and easy installation.
1. PPR pipe connection method
The connection method of PPR tube mainly uses hot melt connection. If there is no good hot melt connection operation method, even if you choose a good pipe, it is still difficult to ensure the installation quality of the pipe. To ensure the connection quality, you must first select the hot-melt tool matching the manufacturer. The heating time and heating temperature of the hot welding machine should be strictly implemented in accordance with the operating regulations.
PP-R pipe adopts the form of hot-melt connection, and the connection between the pipe and the pipe fitting can only be used once. Therefore, when the water supply pipe is concealed in the wall, it should be accurately discharged according to the design requirements and the specific conditions of the construction site. If the pipeline is buried underground, attention should be paid to make the interface of the buried part as few as possible.
Before the pipeline is welded, the surface of the pipeline and the joint must be carefully cleaned to remove oil stains, impurities and burrs on the surface of the pipe. It should be noted that the length of the pipe inserted into the pipe fittings should be appropriate. A uniform flange should be formed at the joint of the connected pipe. If it is uneven, even if there is a gap on one side, it means that the welding is not ideal and it is difficult to ensure that the joint does not leak. connection.
1. The pipes and fittings should be connected by hot-melt method. It is not allowed to directly wire the pipes and fittings. They can be connected to metal pipes with flanges. Pipe fittings with metal inserts must be used to connect the water heaters;
2. Hot-melt connection construction must use reliable hot-melt equipment to ensure the quality of welding;
3. Use special scissors to cut the pipe vertically. The incision should be smooth and free of burrs;
4. Clean the welding parts of the pipe and fittings to avoid the damage of the quality of the joints by sand and dust; use the heating head matching the size of the welded pipe to be fixed on the fuser, connect the power supply, and wait for the heating head to reach the optimal temperature;
5. Mark the welding depth on the pipe with a pencil;
6. Insert the pipes and fittings into the fusion splicer and heat them according to the prescribed time;
7. After the heating is completed, take out the pipe and the pipe fittings and connect them immediately. When the pipe and pipe fittings are connected and matched, if the positions of the two are not correct, a small amount of adjustment can be made within a certain time, but the twist angle should not exceed 5 ℃;
8. After the connection is completed, you must hold the pipe and fittings with both hands to maintain sufficient cooling time. After cooling to a certain level, you can let go and continue to install the next section of pipe.
After the pipeline is connected, the location of the pipeline should be indicated with colored paint on the wall or ground to avoid damage to the pipeline during the second decoration. The hidden water supply riser should be used as a fixed support point when passing through the floor slab to prevent the accumulated expansion and contraction of the riser from generating displacement stress at the junction of the uppermost branch pipe and causing damage to the branch pipe. At the same time, it is also very important for the installation of PP-R pipes to install pipe supports according to the specifications.
2. Precautions for construction and installation of PPR pipes
1. The construction personnel should go through the technical training for the installation of type III polypropylene pipes.
2. The supplied pipes and fittings shall comply with the design regulations, and shall be accompanied by product specifications and quality certificates.
3. Do not use materials with signs of damage. If the quality of the pipeline is found to be abnormal, technical identification or re-inspection should be carried out before use.
4. The openings in the pipeline system installation process should be blocked in time.
5. The pressure level and use occasion of cold and hot water pipes should be reviewed during construction and installation. The pipe marking should face the outside and be in a prominent position.
6. When installing the pipeline, there must be no axial distortion. When crossing the wall or floor, it should not be forced to correct. There should be a certain protective distance between the water supply polypropylene pipe and other metal pipes in parallel, the net distance should not be less than 100mm, and the polypropylene should be inside the metal pipe.
7. Indoor exposed piping should be carried out after the completion of the civil construction. Before installation, it should be properly reserved with the civil construction for holes or pre-buried casing.
8. When the pipeline passes through the floor slab, steel sleeves should be set, the sleeves are 50mm above the ground, and waterproof measures are taken. When the pipeline passes through the roof, strict waterproof measures should be adopted. A fixed bracket should be installed across the front end.
9. The laying of pipelines under the indoor floor should be re-excavated after the backfill of the civil works is tamped. It is strictly forbidden to lay the soil before backfilling or uncompacted soil.
10. The bottom of the trench where the pipeline is laid should be flat, and there should be no protruding hard objects.
11. When the buried pipeline is backfilled, the backfill soil around the pipe shall not be mixed with hard objects and directly contact the pipe wall.
12. Pipes should be installed at the exit of the pipeline, and the height should be 100mm higher than the floor.
13. When the pipeline traverses the foundation wall, metal sleeves should be installed. The clearance height above the reserved holes in the casing and foundation wall shall be not less than 100mm if the design does not specify.
14. When the pipeline crosses the neighbourhood road and the thickness of the overlying soil is less than 70 mm, strict protective measures should be adopted.
3. PPR tube pressure test method
1. Before the installation of the pipeline is completed, a hydraulic test must be carried out to confirm whether the welding condition is good and eliminate hidden dangers.
2. The hydrostatic test should be carried out 24 hours after the hot melt connection. Before the pressure test, the pipeline should be fixed and the joints should be exposed.
3. The test pressure of the cold water pipe should be 1.5 times the working pressure of the piping system, but not less than 1.0MPa; the test pressure of the hot water pipe should be 2.0 times the working pressure of the system, and not less than 1.5MPa.
4. The water meter should be turned off during the pressure test to avoid damage. The manual pressure test pump or electric pump should be used to increase the pressure slowly. The pressure test time should not be less than the specified time.