Cold knowledge: What you must know about PE water supply pipeCold knowledge: What you must know about PE water supply pipe
PE water supply pipes are commonly used in municipal engineering. It is often necessary to find suitable manufacturers to purchase pipes that meet engineering requirements. When inquiring manufacturers, they often need to provide specific parameter requirements. Many people do not understand the common knowledge of PE water supply pipes. Tuck Pipe Co., Ltd. will organize a complete list of common knowledge for PE water pipes:
Q: What types of PE can be divided according to the density of resin?
Answer: PE can be divided into:
Low density polyethylene LDPE (0.9 ~ 0.93g / cm³) is composed of homopolymer of ethylene monomer; medium density polyethylene MDPE (0.93 ~ 0.94g / cm³) is composed of ethylene copolymerized with α-olefin; high density polyethylene HDPE (0.94 ~ 0.965g / cm³) is composed of ethylene copolymerized with a small amount of propylene, butene and hexene monomers.
Q: What types of PE can be divided into long-term hydrostatic strength?
Answer: It can be divided into PE32, PE40, PE63, PE80, PE100, and the most used in water supply are PE80 and PE100.
Q: How did you get the grade by intensity?
Answer: ISO9080 stipulates that in the long-term hydrostatic strength test at 20 degrees, the minimum required hydrostatic strength MRS of the material is determined and multiplied by 10 to obtain the material grade. MRS refers to the minimum required hydrostatic strength of the material under the conditions of 20 degrees and 50 years.
Q: What is the difference between PE63 \ PE80 \ PE100? What do 63, 80 and 100 refer to? What kind of specifications are generally used for building water supply and drainage?
Answer: Material grade MRS (50 years, 20 degrees) MPa PE100 10MPa; PE80 8MPa; PE63 6.3MPa.
The so-called MRS refers to the circumferential tensile stress (after rounding) calculated on the wall of the polyethylene resin pipe when it is continuously applied to the pipe wall for 50 years and the pipe is damaged.
PE63 series of pipes are generally used in urban and rural water supply projects; the nominal pressure refers to the maximum allowable working pressure of the pipe to transport water at 20 degrees.
PE80 series of pipes are generally used in urban water supply projects; the nominal pressure refers to the maximum allowable working pressure for pipes to transport water at 20 degrees.
PE100 series of pipes are especially suitable for large-caliber, high-pressure water supply projects; the nominal pressure refers to the maximum allowable working pressure of the pipe to transport water at 20 degrees.
PE80 PE100 gas can also be used.
The corresponding relationship between the standard size ratio of PE water supply pipes produced by different grades of raw materials and the nominal pressure is as follows:
Q: What are the basic parameters that have a greater impact on PE?
Answer: The basic parameters that have a greater impact on PE are molecular weight, molecular weight distribution, and crystallinity. The molecular weight is characterized by the solution flow rate MFR.
Molecular weight distribution describes the length and mass of polymer molecular chains. If all the chains are relatively close, it is called a narrow distribution, otherwise it is called a wide distribution, which is characterized by the melt flow ratio. Crystallinity is characterized by density.
Q: What effect does density have on PE pipes?
Answer: The density is low, and the "inflection point" of the transformation of toughness and brittleness appears late, that is to say, the density is high and the toughness and brittleness are poor.
Q: What effect does molecular weight have on PE?
Answer: The molecular weight is large, and the PE has good impact resistance. Increasing the molecular weight of PE is an effective method to improve the long-term strength and stress cracking resistance of PE pipes.