Plastic polypropylene pipes are the most inexpensive pipes for heating in the house today. They can be mounted both outside the wall and under plaster. With good quality components and competent installation, they can last for more than a dozen years, but in general, polypropylene pipes have significant drawbacks that can affect the quality of the heating system itself. We want to talk about them.
one Large linear expansion
The polypropylene plastic pipeline has large linear expansion. Under the influence of temperature, the pipe can expand, forming a wave. Linear expansion for polypropylene is 2.5 mm per 1 running meter.
If you provide a compensator, you can forget about expansion. If there is no compensator, pipes that are even after installation can become wavy in a couple of days. Because of this, it will be necessary to fasten the pipeline to the wall with a smaller pitch. However, even with frequent fastening, the pipe will not look perfect. Although linear expansion does not affect the performance of the product, it still spoils the appearance.
2 A huge number of joints
These products are not sold in bays, but in pieces of 2 – 4 meters, which is why they often have to be joined. Also, the number of joints increases due to various turns and angles. For the heating system in a house with an area of 100 m2 there can be about a hundred such joints. And if we consider that most of the polypropylene pipes are intended for concealed installation, then the overwhelming majority of them will be hidden in the plaster.
Please note that the connection is made by soldering two pieces of pipe, and all this is done by a person. If a person did not hold a little or, on the contrary, overexposed the pipe in the apparatus, then the connection becomes unreliable and after a couple of years it may leak. In this case, the wall will have to be opened.
3 Narrowing the diameter of the joint
Narrowing (welding) of the joint diameter can occur directly during pipe welding. An unprofessional installer or you yourself (if you are soldering for the first time) can weld the joint by narrowing its diameter. This increases the resistance in the pipeline and deteriorates the flow. If there are several such “jambs” along the entire length of the pipeline, then the operation of the heating system may deteriorate significantly.
Unfortunately, quite often such “jambs” are found when installing pipes in apartment buildings, so be careful when choosing installers.
four Using fiberglass as reinforcement
Any polypropylene pipe is reinforced with fiberglass or aluminum foil. However, due to the fact that aluminum foil significantly increases the cost of the product, many manufacturers abandoned its use, replacing it with fiberglass.
By itself, fiberglass is afraid of freezing temperatures, and also does not tolerate falls. But often polypropylene pipes are stored in unheated warehouses of shops and wholesalers. It is also difficult to verify how the material was transported from the manufacturer’s plant to a specific store. Because of this, there is a possibility of getting a low-quality product, and you cannot check if everything is in order with the reinforced layer.
five The connection of metal with plastic in fittings
Some connectors have a metal insert. Under the influence of temperature, plastic and metal expand in different ways, so a leak can occur in their connection. Of course, a similar situation can occur if you use fittings from unscrupulous manufacturers. Therefore, we recommend that you do not save money, but it is possible to buy connections a little more, but from trusted manufacturers.
Of the good ones, we can recommend FV-Plast, Kalde or Valtec are also suitable. Their plumbing products are not the cheapest, but they are of high quality.
6 Heating system service life
Most manufacturers indicate that the maximum service life of polypropylene pipes is about 50 years. However, this is possible only if all the rules and requirements specified in the passport for the product are observed. Unfortunately, practice has shown that this material serves for 20 – 25 years, after which it begins to crack. Of course, individual cases show that plastic pipes made of polypropylene can last longer, but provided that each of the chain “manufacturer-seller-owner” ideally followed the rules of storage, transportation and operation of products.