PPR pipes are commonly used for both cold and hot water pipes in daily life. PPR pipes are a relatively common pipe material. What are their advantages, and why are they so popular?
In addition to the common plastic pipe characteristics of being lightweight, corrosion-resistant, scale-resistant, and having a long service life, PPR pipes are also non-toxic, hygienic, heat-insulating, energy-efficient, long-lasting, and easy to install.
PPR Pipe Connection Methods
PPR pipes are primarily connected by hot melt. Without proper hot melt operation techniques, even if you choose high-quality pipe materials, it's difficult to guarantee pipe installation quality. To ensure connection quality, it's crucial to select the hot melt tools that match the manufacturer's specifications. The heating time and temperature of the hot welder must be strictly followed according to the operating procedures.
When a hot melt connection is used for PP-R pipes, the connection between the pipe and fitting is a one-time use only. Therefore, when concealing water supply branches in walls, precise cutting must be performed according to the design requirements and the specific conditions of the construction site. If the pipeline is buried, it should be carefully laid to minimize the number of joints in the buried section.
Before welding the pipes, carefully clean the pipes and joint surfaces, removing any oil, impurities, and burrs from the pipe surfaces. The pipe should be inserted into the fitting to an appropriate length, and the flange at the joint should be even after connection. If it is uneven, resulting in unevenness on one side, this indicates an imperfect weld, making it difficult to guarantee a leak-proof joint. In this case, reconnect the pipes promptly.
(1) The connection between pipes and fittings should be made by hot melt. Direct threading on pipes and fittings is not allowed. Flanges can be used for connection with metal pipes, and fittings with metal inserts must be used for connection with water appliances.
(2) Reliable hot melt equipment must be used for hot melt connections to ensure the quality of the weld. (3) Use special scissors to cut the pipe vertically. The cut should be smooth and free of burrs.
(4) Clean the welding parts of pipes and fittings to avoid sand, dust, and other contaminants that may affect the quality of the weld. Fix the heating head that matches the size of the welded material on the hot melter, connect the power supply, and wait for the heating head to reach the optimal temperature.
(5) Mark the weld depth on the pipe with a pencil.
(6) Insert the pipes and fittings into the welding machine and heat them for the specified time;
(7) After heating, take out the pipes and fittings and connect them immediately. When the pipes and fittings are connected, if the positions of the two are not correct, they can be adjusted slightly within a certain time, but the rotation angle must not exceed 5°C;
(8) After the connection is completed, you must hold the pipes and fittings tightly with both hands and maintain sufficient cooling time. Only after cooling to a certain degree can you let go and continue to arrange the next section of pipe. After the pipes are connected, the position of the pipes should be marked on the wall or floor with colored paint to prevent secondary decoration from damaging the pipes. Concealed water supply risers should have a firm support point at the point where they pass through the floor to prevent the riser from accumulating and expanding and contracting and generating displacement stress at the top branch pipe connection, causing damage to the branch pipe. At the same time, setting up pipe supports according to standard requirements is also very important for the arrangement of PP-R pipes.
PPR Pipe Construction and Installation Mistakes
1. Construction personnel must undergo technical training in Type III polypropylene pipe installation.
2. The pipes and fittings provided must comply with design specifications and be accompanied by product specifications and quality certificates.
3. Materials showing signs of damage must not be used. If any pipe quality abnormalities are found, a technical appraisal or re-inspection must be conducted before use.
4. Openings in the piping system during installation must be promptly sealed.
5. During installation, the pressure ratings and locations of hot and cold water pipes must be verified. Pipe markings should face outward and be located.
6. Pipes must be installed with no axial distortion. Forced corrections should not be used when passing through walls or floors. When polypropylene water supply pipes are laid parallel to other metal pipes, a protective distance of at least 100 mm should be maintained, and the polypropylene pipe should be placed on the inside of the metal pipe.
7. Indoor exposed piping should be installed after civil engineering work is completed. Precisely reserved holes or pre-buried casing should be prepared in coordination with civil engineering work before installation.
8. When piping passes through floor slabs, steel casing should be installed, 50mm above the ground level, and waterproofing measures should be implemented. Strict waterproofing measures should be implemented when piping passes through roofs. A secure support should be installed at the front of the crossing.
9. Pipe laying below the ground level in key areas should be carried out after the backfill soil has been compacted and re-excavated. Piping before backfill or in uncompacted soil is strictly prohibited.
10. The bottom of the trench for laying pipes should be flat and free of protruding fixed objects.
11. When backfilling buried pipes, the backfill soil around the pipes must not contain any fixed objects that would come into direct contact with the pipe walls.
12. Where the pipes emerge from the ground level, a protective pipe should be installed, 100mm above the ground level.
13. When pipes pass through foundation walls, they must be installed with metal casings. The clearance between the casing and the reserved hole in the foundation wall should be no less than 100 mm, unless otherwise specified.
14. When pipes pass through neighborhood paths where the cover soil thickness is less than 70 mm, strict protective measures must be implemented.
PPR Pipe Pressure Testing Guidelines
1. A water pressure test must be conducted before completing pipe installation to confirm the weld condition and eliminate potential hazards.
2. The water pressure test should be conducted 24 hours after the hot-melt connection. The pipes must be secure and properly secured before the pressure test.
3. The test pressure for cold water pipes should be 1.5 times the operating pressure of the piping system, but not less than 1.0 MPa; the test pressure for hot water pipes should be 2.0 times the operating pressure of the system, but not less than 1.5 MPa.
4. During the pressure test, the water meter should be turned off to prevent damage. A manual pressure test pump or an electric pump should be used to increase the pressure slowly. The test time must not be less than the specified time.