Ningbo Fangli Technology Co., Ltd. is a mechanical equipment manufacturer with nearly 30 years’ experiences of plastic pipe extrusion equipment, new environmental protection and new materials equipment. Since its establishment Fangli has been developed based on user’s demands. Through continuous improvement, independent R&D on the core technology and digestion & absorption of advanced technology and other means, we have developed PVC pipe extrusion line, PP-R pipe extrusion line, PE water supply / gas pipe extrusion line, which was recommended by the Chinese Ministry of Construction to replace imported products. We have gained the title of “First-class Brand in Zhejiang Province”.
The emergence of PE-RT has attracted people's attention because of its good stability and long-term pressure resistance, easy bending, convenient construction, good impact resistance, high safety, aging resistance, long service life, convenient processing technology, easy quality control, melting and recycling of waste pipes. As PE-RT is more and more well known, the situation of PEX pipe dominating the world in the floor heating market is gradually broken. Nowadays, PE-RT pipe and PEX pipe have become the mainstream products in the floor heating market.
PE-RT pipe has developed rapidly and realized technical upgrading
As the number of consumers of floor heating pipes increases year by year from north to south, PE-RT pipes usher in a golden period of its development. At present, China has developed into the world's largest PE-RT market. At the same time, PE-RT has been updated and upgraded to become the fastest-growing pipe in recent years.
So why can PE-RT develop so fast? This is because it has certain advantages. Ordinary PE pipes can only be used for cold water below 40 ℃, while PE-RT pipes can be used for the transmission of cold and hot water at the same time. In the 1990s, Dow Chemical first successfully developed PE-RT, and later SK, LG and other companies also developed their own brands. These belong to the first generation of PE-RT materials, referred to as PE-RTI. With the continuous development of PE synthesis technology, since 2000, Dow Chemical, Basel and some Korean companies have successively launched the second generation PE-RT, referred to as PE-RTII. Compared with PE-RTI, PE-RTII has higher strength at high temperature and better creep resistance. It can reduce the thickness of thin wall in use. Of course, it can save raw materials, reduce costs and increase the diameter.
PE-RTII has obvious advantages at high temperature
However, this advantage of PE-RTII can be clearly reflected in the high-temperature hot water environment. This can be seen from the size selection of PE-RTI and PE-RTII:
The selection of PE-RT pipe size shall be determined according to the service environment. Under different service conditions, as the basis for design and use, the s value of pipe series is also different. The S value is associated with the pipe size. Pipes with the same series number S value have the same size. That is, when the pipe S value is selected, the size of the pipe is selected. However, the different wall thickness of pipes, its S values is different. For example, PPR φ S5 and S4 series pipes are often used in cold water system, with wall thickness of 2.0mm and 2.3mm respectively; When it is used in hot water system, S3.2 and S2.5 series are generally selected, and the wall thickness is 2.8mm and 3.4mm respectively.
So, how to choose the size of PE-RTI and PE-RTII pipes in the floor heating system? In this regard, ISO22391-2009, German standard DIN16833-2009 and the new draft national standard (standard CJ / t175-2002 of the Ministry of construction) have made relevant provisions. According to the data given in these standards, we can see that the number of pipe series selected by PE-RTI and PE-RTII under the same design service pressure is exactly the same, that is, the size is exactly the same.
Why? The main reason is that PE-RTII has more significant advantages in high-temperature hot water environment, but the temperature of floor heating system is lower. Compared with PE-RTI, PE-RTII has little improvement in strength at low temperature, which is not enough to reduce wall thickness, save raw materials and increase diameter. If it is in high temperature environment, this characteristic of PE-RTII will be obviously reflected.
At present, the domestic cold and hot water pipe market is mainly occupied by PPR pipe. Can PE-RT pipe further expand its influence and occupy a leading position in the domestic hot and cold water market with its current advantage of high temperature resistance? We need to wait and see.