Pipe selection for cold water 2

Pipe selection for cold water 2

3. Service life in cold-water materials

Polypropylene, metal-plastic, HDPE in cold-weather materials will fully serve the stated 50 years – there is no overheating and transcendent pressure, hence a rating of 3.

Crosslinked Polyethylene, due to the lower performance at the maximum working pressure (10 bar), it can potentially serve less – in the absence of a pressure regulator, since hydroblows still occur during scheduled repairs. And handicraft pressure tests showed not high reliability of cross-linked polyethylene (Rehau) in the parameter “working pressure”.

Grade 2.

Galvanization – Grade 2, due to the potential low corrosion resistance of the pipe, if the zinc coating is damaged. According to technical standards, the corrosion rate of a black pipe under normal conditions is 0.1 mm per year. In the thread area, the pipe thickness is usually about 2-2.5 mm, respectively, the service life, taking into account the zinc coating, is at least 25 years. On the one hand, it’s good, but on the other hand, it loses to polymer pipes.

Corrugated corrugation – rating 2. I will say right away that the rating is a subjective, not very verb in the words of the manufacturer :). Theoretically, stainless steel should stand for a very long time, however, from the experience of our organization, stainless corrugated pipes are very much afraid of any friction. The wall thickness is only 0.3 mm and is frayed rather quickly under vibration conditions. In housing, the only vibrations that can be (we do not take into account construction work, earthquakes, etc.): pressure surges (water hammer), mechanical pipe touches, thermal expansion of compression. The declared service life of the system of such pipes is 30 years. Not bad at all.

Copper – rating 3.The only factor that significantly reduces the durability of copper pipelines is dirty water with abrasive impurities (rust from the riser, sand, etc.). A filter is required for normal operation.


3 points – Polypropylene, metal, HDPE, Copper

2 points – Crosslinked polyethylene, galvanized, stainless corrugation.

4. Performance

Here, for HVS, you can immediately summarize πŸ™‚

3 points for all pipes except cross-linked polyethylene (due to low working pressure) and stainless corrugation (due to noise when water flows through the pipe) Cross-linked polyethylene and stainless corrugation – 2 score

5. The convenience of installation.

In my case – see the photo above. The installation of pipes must be done in cramped conditions.

Polypropylene and HDPE grade 1Installation of polypropylene in such conditions is a great risk to perform it incorrectly, which will lead to further leaks or narrowing of the pipe section. Even the experts of large firms in our city in such errors. In addition, I put in a pipe from a niche with risers to the bathroom made behind the sewer riser and under a pipe with hot water – it is very difficult to crawl there. PND, it seems to be generally impossible to collect here.

Metal – plastic – grade 2. When installing metal-plastic there are requirements for a minimum bending radius. Failure to do so will result in pipe ruptures. Theoretically, the required radii (60 mm) can be fulfilled, but practically it is difficult to control the sewer riser.

Crosslinked Polyethylene – Grade 3. Flexible when using a hairdryer and not prone to fracture. Ideal material for entering a pipe from a niche with risers into the bathroom.

Galvanization and copper – rating 1. The reason is the same as for polypropylene – pipes with fittings will not crawl into the holes in the wall, and making holes with holes is not comme il faut πŸ™‚

Corrugated stainless steel – rating 3 due to flexibility and small bending radii

Summary :

3 points – cross-linked polyethylene, stainless corrugation

2 points – metal plastic

1 point – polypropylene, HDPE, galvanization, and copper

6. Maintenance

Polypropylene – 2 points.Joints with fittings must be inspected occasionally (at least once every 3-5 years) for leaks, it is also necessary to inspect the pipe for damage. And such is found in pipes in the form of bubbles or cracks. In cold weather this is unlikely, but still … However, the fittings for polypropylene in my case will be located in hard-to-reach places (behind the sewer riser and deep under the bath).

Metalloplast – 2 points. When using press fittings, inspection is also necessary, but all connections will be in the direct access zone, in principle, the assessment maybe 3. When using fittings with a split ring, inspection is required more often (once every six months or a year), but since the fittings are planned to be placed in accessible areas – score 2, not 1.

Cross-linked polyethylene – almost permanent compounds, are in the direct access zone -score 3

PND – 2 points for the same reasons as polypropylene.

Galvanization – 3 points when using a pipe bender – then there will be no fitting behind the bathtub and riser, and the fitting will be inaccessible areas. However,

Corrosion-proof corrugation – 3 points for the same reasons as cross-linked polyethylene

Copper – because of fittings – 2 points


3 points – cross-linked polyethylene, galvanization, stainless corrugation

2 points – polypropylene, metal, HDPE, copper.

7. The cost of the pipe and installation.

Polypropylene – 3 points. The cheapest material and installation

Metalloplast – the price of the pipe in the average price range, fittings are quite expensive – in the region of 200-300 rubles apiece. Score – 2 points

Cross-linked polyethylene is a rather expensive pipe (you can put up with it because I need no more than 4 meters) and very expensive fittings – 400-500 + rubles apiece. The tool costs about 50,000 rubles, but you can rent for 1000-1500 rubles per day. Assessment – 1 point

PND – 2 points – inexpensive pipe and expensive fittings Galvanization – 2 points. A relatively inexpensive pipe, but you need equipment for bending pipes, you need the skill of installing threaded pipe joints. There is a possibility of alteration or tightening of the thread. complicated installation.

Corrugated stainless steel – 2 points. If you use more reliable union nuts (with flaring), then the installation is elementary. But the cost of the pipe is high and besides, you need to buy a flare or order pipes of finished length (they will flare in the store).

Copper – 1 point. Expensive pipe, fittings, specialized installation and the need to have the skill of such installation.


3 points – polypropylene

2 points – metaplastic, IPA, galvanized, stainless corrugation

1 point – linked polyethylene, copper

Zhirnenkim, I highlighted those positions in which there is no grade 1. Although the issue of price is not the most important when reliability is at stake.

Bottom line: in conditions of poor access to the pipe mounting area, it is preferable to choose between metal, cross-linked polyethylene and stainless corrugation. Since the service life and technical characteristics of the pipes are almost identical in general, attention should be paid to the chemical and bacteriological inertness of the pipe material. What is more important? I thought about this for a long time, but my work colleague said a simple phrase: it’s better to let bacteria get in than any chemistry will accumulate. Reasonable thought.

As a result, I am now at a break-up: cross-linked polyethylene or stainless corrugation. For me, both materials are the same in many respects, there remains only an intuitive distrust of thin stainless steel πŸ™‚

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