Regulate the development of the PE-RT floor heating pipeline industry to improve standards

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These advantages of PE-RT pipe make many manufacturers see the business opportunities, they have started production. At present, PE-RT pipe manufacturers have grown from a few of the original few to nearly 1,000, and there are at least three suppliers of PE-RTII pipe materials. The application of PE-RT pipelines and the production technology of pipeline raw materials have all achieved rapid development. However, the rapid development of the PE-RT pipe industry also exposed many problems.

Raw material adulteration PE-RT hidden problems

In fact, at the beginning of the development of domestic PE-RT pipe, many people questioned its product qualification rate. The reason for this is mainly due to the fact that some PE-RT pipe manufacturers are not producing well and their quality is not strictly controlled. Mainly in two aspects:

First of all, there is adulteration in raw materials. In order to reduce costs, some companies add linear low density polyethylene to the pipeline production process. This kind of pipe is often difficult to pass the short-term hydrostatic strength test; some companies are relatively "brilliant", they use non-PE-RT pipe special medium and high density polyethylene material to produce PE-RT pipe, while adding some linear in the raw material Low density polyethylene material to reduce costs. According to the currently implemented industry standards, pipes produced from these raw materials are not easily detectable by normal-temperature hydraulic test.

After blending polyethylene materials of different densities, the refractive index of the produced pipe is different due to the different density and crystallinity of the material, so the pipe color will be different. In order to mask the difference in color and transparency between their pipes and pipes made from genuine raw materials, these companies often add color masterbatch to their production, making consumers unrecognizable.

In addition, in view of the low hydrostatic index of type II PE-RT tubes in current international standards, I-tubes can also pass short-term performance tests, and domestic production of I-type materials as type II materials also occurs. Unfair competition has been created for the normative Type I and Type II product manufacturers.

Secondly, in the aspect of pipe quality inspection, there is a phenomenon that enterprises do not control strictly. The quality of PE-RT pipe depends not only on the raw material but also on the quality control of the pipe from production to delivery. Enterprises in the production process should pay close attention to the thickness and appearance of the pipe to ensure that the pipe wall thickness is uniform. At the same time, the surface of the pipe wall should not contain foreign matter or other streaks that affect the performance of the pipe. Since the floor heating pipes produced by PE-RT pipes are generally in the form of coils, the pressure test of the entire pipe should be conducted during the factory inspection to ensure that the entire pipe is a qualified product. However, some domestic small-scale PE-RT pipe manufacturers are neglected to manage and rarely check in real time in the production process. It is inevitable that a large number of unqualified products will be produced. However, at the time of factory inspection, these enterprises often only conduct sampling inspections, which causes a large number of unqualified products to enter the construction site, and causes many hidden troubles for the floor heating project.

Regulating industry development and improving standards is crucial

In this case, it is of utmost importance to issue a comprehensive set of national standards for PE-RT piping systems.

At present, this new national standard (abbreviated as “new national standard”)—“PE-RT piping system for hot and cold water” is already in the approval stage. In the formulation of the new national standard, the drafting group took full account of the current state of production and technology. At the same time, it fully discussed some unregulated market phenomena in the country and put forward strong regulatory measures for some of the issues mentioned above.

First of all, the new national standard requires that the floor heating pipes should be natural, and the hot and cold water pipes for living should be gray, and other colors should be determined by both the supply and demand sides. This can largely avoid the phenomenon of some companies in adulteration of raw materials in the floor heating pipe.

Second, distinguish type I PE-RT tubes and type II PE-RT tubes. The new national standard will pull the I-type tube and the II-type tube apart from their performance (Material requirements: Type II tube hydrostatic strength reference line increased; Product testing: hydrostatic test control point stress increases). This is conducive to a fair competition between enterprises.

Finally, the MFR (melt flow rate) rate of change is controlled. Excessive use of recycled materials will be reflected in the rate of change of MFR for the product and the raw materials used. Therefore, controlling the rate of change of MFR of the raw materials and pipe products used before and after processing is one of the important indicators for controlling the quality of products during the processing.

The new national standard sets specific standards for MFR. That is, the difference between the MFR of the product and the MFR of the raw material should not exceed 0.3 g/10 min, and this difference should not exceed ±20% of the product MFR or raw material MFR. Compared with international standards, this new national standard is more stringent. This can effectively prevent companies from adding too much recycled material in the production process.

The development of an industry is inseparable from the constraints of standards or norms, and it is inseparable from the self-discipline awareness of the company itself. If the company can correctly understand the meaning of the standard or the specification and truly implement it, then the industry must be a healthy development industry. On the contrary, fake and shoddy products flood the entire industry, and ultimately cause the company itself to suffer losses. Therefore, companies should strengthen self-discipline, take social responsibility, and establish long-term development. If the company does not strengthen self-discipline, then even if it is profitable, it will be treated as a malignant tumor for society and the industry.