At the beginning of my career, working as a plumber, 15 years ago I was taught the basics of this ancient craft. How to wind up the threads, how to hold the gas wrench correctly... how to dodge flying objects. The last skill was required when it was possible to "screw up".
In our team, there was an old, experienced locksmith. Sometimes he took me to "co-workers". When communicating with potential customers, he discouraged them from using metal plastic. He offered other, alternative pipes. His reasoning was as follows:
- The metal-plastic pipe is unreliable. With hot water or heating, there is a high risk of swelling of the pipe layers. In fact, there were such moments quite often.
- Good fittings for connecting metal-plastic pipes have a high price. That forces the customer to buy cheaper, low-quality analogs.
- Threaded fittings periodically require tightening, respectively, if this is not done, then the leaks will be permanent. We did not use press fittings, for some reason this technology did not take root in our country.
But you need to understand that a metal-plastic pipe has a number of advantages. I will list them briefly: Relative ease of installation. Pipes in coils. Metal-plastic easily takes the desired shape. Oxygen barrier, an important aspect when installing heating systems. Convenient marking of the pipe length.
If the pipe is so good for installation, according to the last points, then why was it not liked by plumbers at that time, and even now? The fact is that, a good quality pipe that does not swell. Good fittings that do not leak, the press fit crimping tool cost a lot of money. In our provincial town, with low earnings, they did not carry pipes of famous brands. They were quite expensive. And they drove cheap China and threaded fittings, which were tightened with ordinary keys.
Accordingly, the people had such a negative impression about this material.
From SW. Timofey Mikhailov.