All necessary utilities are usually assembled from plastic / metal-plastic pipes. If the working medium in the installed system is hot water, then reinforced-plastic pipes will be required. For sewers, polypropylene and PVC products are used. Before starting the assembly of the system, it is necessary to select and purchase fittings, without which it is impossible to connect the pipes. If you want to learn more about these products, as well as how to choose fittings for reinforced plastic pipes, we recommend that you read this article.
How to choose fittings for metal-plastic pipes, depending on their type
It will be easier to choose fittings for metal-plastic pipes if you know about their main types:
Compression fittings for metal-plastic pipes. Such products must be selected if you want to create conditionally detachable connections.
More modern push-fittings for metal-plastic pipes. They are necessary if you want to create detachable connections. The installation process of push fittings is simple and does not require any special tools.
Press fittings for metal-plastic pipes. They are chosen if you want to create permanent connections.
Compression fittings
They are easy to install: you only need adjustable or open-end wrenches. With the help of such fittings, a detachable connection is obtained. That is, if a leak is found several years after their installation, then it can be easily eliminated by tightening the nut stronger. Compression fittings for metal-plastic pipes are not allowed to be “hidden”.
Compression fitting for multilayer pipes consists of:
- Union nut;
- Fitting;
- Split crimp rings.
You have the opportunity to choose the type of compression fittings you need for multilayer pipes. It can be:
- Tees for metal-plastic pipes;
- Corners;
- Crosses;
- Adapters;
- Water sockets, etc.
Press fittings
The press fitting is a non-separable design: a body with a union and a compression sleeve. The joints are sealed with grooves (there are 2 or 3 of them, synthetic rubber is poured into each of them) located on the fitting.
Press fittings for multilayer pipes create a permanent connection. They should be selected for the assembly of pipes hidden in the wall. They serve for 30 years .
Reinforced-plastic products are not suitable for creating external communications, since at negative temperatures, pipes with frozen water in them can burst.
To install press fittings for metal-plastic pipes, you will also need to purchase press tongs, which cost from 1 to 5 thousand rubles. The jaws can be either manual or hydraulic with microprocessor control.
Push fitting
Inside the push-fitting there is the same union with O-rings as in the compression one. In order not to rip off the rings, the metal-plastic pipe should have a perfectly round internal section and a removed internal chamfer, which ensures a smooth entry into the Welding Fittings.
The metal-plastic pipe is securely fixed using a stainless steel ring with lugs directed towards the fitting. Unfortunately, the ring is only designed for a specific pipe wall thickness. Thus, if you choose pipes with slightly thicker walls, you will have problems installing them in the connector. And if the walls turn out to be thinner, then the metal-plastic pipe can be pulled out of the joint with a certain effort.
More articles like this here.