When purchasing pipe, people often ask what the difference is between PR pipe and PVC pipe. The difference between PPR pipe and PVC pipe is based on the diameter of the pipe, which requires experience.
Main Differences:
1. Color: PPR pipe is tough. High-quality pipes have a glossy, light, creamy yellow hue, while lower-quality pipes have a mixed color. PVC pipe is creamy white and hard and brittle. Its cross-section is matte, but its surface is shiny.
2. Wall Thickness: PPR and PVC pipes of the same diameter differ in their wall thickness, with PPR pipes having thicker walls and PVC pipes having thinner walls.
All PPR and PVC pipes have markings on them, making them easy to distinguish. PPR pipes are known for their toughness. For pipes of the same diameter, the wall thickness of PPR pipes is generally determined by their outer diameter, with sizes ranging from 20, 25, 32, 40, 50, and 63 mm. Small-diameter pipes can be difficult to distinguish, so use a ruler to measure the outer diameter. If convenient, use a handy pipe fitting to test the pipe.
3. How to Prevent Cold Brittle Fracture in PPR Pipe Applications
1) PPR pipes must not be thrown, dropped, rolled, or dragged during transportation.
2) Pipes must be stored in warehouses or simple sheds, and the stacking height must not exceed 1.5 meters.
3) During the construction process, the following must be observed:
① PPR pipes are less hard and rigid than metal pipes. They should be protected during transportation and construction to prevent mechanical damage from inappropriate external forces. Mark the pipe locations after concealed installation to prevent damage from secondary renovations.
② PPR pipes exhibit a certain degree of low-temperature brittleness below 5°C. Exercise caution during winter construction. Cut slowly with a sharp knife. Avoid heavy pressure or impact on installed pipes. Cover areas susceptible to external forces with protective materials if necessary.
③ Before cutting, if any pipes show signs of stress whitening due to external forces, they should not be used.
④ Before hot-melt jointing, carefully inspect the pipes for damage. This is especially true for the inner wall, as when subjected to external forces, the inner wall cracks first, followed by the outer wall. Avoid using pipes with cracked inner walls but intact outer pipes.
⑤ After installation, pipes must be pressure tested before direct burial or concealed installation. The test pressure for cold water pipes should be 1.5 times the system operating pressure, but not less than 0.9 MPa; the test pressure for hot water pipes should be 2 times the system operating pressure, but not less than 1.2 MPa.
4. Related Phenomena
1) Cracks or breakages in the pipes are discovered during renovation.
2) Cracks are discovered in PPR pipes during pre-installation.
3) Linear cracks appear in PPR pipes during pressure testing or after a period of use.
4) Cracks appear in welds after a period of use.