How To Prevent Low-temperature Brittleness Of PPR Pipe?
With the advent of winter, the temperature is getting lower and lower, and the brittleness of PPR pipes is gradually increasing, so that in the process of production, transportation, and installation if you do not pay attention to prevention, it will cause hidden dangers such as brittle fracture of PP-R pipes. It can detect and eliminate hidden dangers in time, and PP-R pipes are prone to pipe bursts during use, which will affect the use of customers.
So, what is low-temperature brittleness?
How to prevent the low-temperature brittleness of PPR pipe? The following IFAN will take you to learn more. This is our Facebook Website:www.facebook.com
1. What is low-temperature brittleness?
Low-temperature brittleness means that the impact absorption energy of the material decreases with the decrease in temperature. When the test temperature is lower than Tk (ductile-brittle critical transition temperature), the impact absorption energy decreases significantly, and the material changes from a tough state to a brittle state. This phenomenon is called Low-temperature brittleness.
2. Why does PPR pipe have low-temperature brittleness?
PPR is random copolymerized polypropylene, which is obtained by random copolymerization of propylene monomer and a small amount of ethylene monomer under the action of heating, pressure, and catalyst. Ethylene monomers are randomly distributed in the long chain of propylene, and the ethylene monomers are generally controlled between 3-5%. The ethylene content and the polymerization mode of ethylene and propylene determine its low-temperature brittleness. When the corresponding ambient temperature of the PPR pipe is lower than 5°C, it has the above physical properties.
3. What are the manifestations of low-temperature brittleness of PPR pipe?
When the ambient temperature is low, the toughness of the PPR pipe decreases, showing brittleness. When the pipe is impacted by external force or heavy pressure, linear cracking will occur, and the cracking starts from the inner pipe and extends to the outer pipe. After the pipe is cracked by the force of a point, the crack will grow rapidly along the axis of the pipe in an instant. This characteristic is called rapid crack growth. In addition, pipes are injured by an external force during transportation, construction site, and installation in winter, and pipe breakage will occur during use.
How to prevent the low-temperature brittleness of PPR pipes?
①PPR pipe storage
1) PPR pipes are required to be stored in simple sheds or warehouses, but the stacking height should not exceed 1.5 meters.
2) It is strictly forbidden to roll, throw, drop or drag the PPR pipe during the handling process.
②PPR pipeline construction
1) After the pipeline is installed, it must be tested for pressure before direct burial and non-direct burial. Make an appointment with a professional to conduct a home inspection.
2) Compared with metal pipes, PPR pipes have lower hardness and poorer rigidity. They should be protected during handling and construction to avoid mechanical damage caused by inappropriate external forces. After concealed laying, the position of the pipeline should be marked to avoid secondary decoration from damaging the pipeline.
3) Before the pipe is cut, if the pipe is found to have stress whitening due to external force factors, the pipe cannot be used.
4) Before the pipe is hot-melt connected, it is necessary to carefully check whether the pipe has been damaged. Especially the inner wall, because when the pipe is subjected to external force, the inner wall ruptures first, and then to the outside. Avoid using tubing that has cracked the inner wall but not the outer tube.
5) There is a certain low-temperature brittleness of PPR pipe below 5°C, so be careful in winter construction, and use a sharp knife to cut slowly when cutting the pipe. Do not press or knock the installed pipes, and cover the parts vulnerable to external forces with protective materials if necessary.
③PPR pipe use
For the ppr water pipes that have been used, use ppr special protective sleeves outdoors, wrap all the exposed pipes, or wrap them with linen cotton cloth. For indoor pipes, keep the indoor temperature not lower than 0°C, as the water in the pipes freezes and expands below 0°C, the huge expansion pressure may cause the pipes to rupture and leak. If there is no one in the house for a long time, or if there is no heating during or after the renovation, the main valve should be closed, and all the faucets in the room should be opened to drain the water in the pipes.
④PPR pipe pressure test
After the pipeline is installed, it must be tested for pressure before direct burial and non-direct burial. In winter, after the inspection is completed, take insulation measures.
If you have more questions, please contact IFAN. IFAN has specialized in PPR pipes for 30 years. Welcome to buy!
