Types of PEX tubing
Currently, the US market for PEX pipe the following types:
- PVC pipe
- PEX tubing
- tubing of metal
- Polypropylene tubing
PEX tubing of PVC emerged in the mid 30s of last century. The best known U.S. company PVC pipe Genova Systems. They were originally intended only for the individual low-rise building and have limited dimensions. Connection of tubing and fittings by using glue.
At present, European countries virtually abandoned the use of these pipelines, even in cold water. There are several reasons. First, over time, activates the process of separation of toxins, including chlorine, which is a carcinogen broad-spectrum, and secondly, PVC can not withstand the increased demands on the stability for emergency and fire, because a combustible material, combustion of which gives the poisonous gases – oxides (CO) and dioxide (CO2). Today PVC pipe is used in Europe only in the sewer systems, and in the cheapest homes.
In our country, pressure tubing of PVC mainly used for underground water pipelines outside of buildings. Indiscriminate use of high-rise building, unfortunately, has a negative experience: they can not withstand even the warranty period of one year. In Russia, a considerable part of these tubing is in the form of humanitarian aid, the rest is made directly at domestic plants.
PEX tubing videos
tubing made of PEX, appeared in the mid 50s. One of the advantages of these tubes is that they are resistant to low temperatures down to -20 ° C. This allows you to operate such tubing and carry their seal even in winter conditions. PEX tubing are connected by mechanical means – brass or polypropylene fittings. Their field of application – mostly cold water. At higher temperatures the strength of PEX decreases, and it goes into the PEX-viscous state. PEX is aging rapidly under direct sunlight. Therefore, the use of PEX tubing in outside open networks stabilize them, filling the polymer with soot.
In the early 70′s there were tubes of “crosslinked” PEX, characterized by higher strength and higher resistance to temperature.
The joining of linear molecules of PEX increased its heat resistance and strength, but lost the ability to weld the polymer. For cross-linking using high-density PEX, cross-linking is carried out by several methods using ionizing radiation, peroxides, and organosilicon compounds (silanol cross-linking). These tubes can be used already in hot water systems and tubing provided with “kislorodozapirayuschim layer” – and heating systems.
The next stage of the pipe lines are metal-tube, five-layer structure which are: the main pipe of cross-linked PEX adhesive layer deposited on its outer surface, a layer of aluminum foil with a thickness of 0.1-0.15 mm, re-glue layer and the outer protective shell of PEX. Igotavlivayutsya pipe made of PEX by extrusion, in which the aluminum strip, welded by ultrasound in joint, is covered on both sides with glue and layers of PEX of suitable thickness
Metal-tube are five times lower coefficient of linear expansion and is well protected from oxidation. In addition, metal-pipe bend well and keep them imparted form. Of these tubing are well fitted for the complex configuration of the system, all kinds of eyeliner, such as heating appliances. Metal-tube wiring are effective in the open, especially for connecting various devices (heaters, water heaters, etc.). Unfortunately, the maximum diameter of such tubing up to 40 mm, which significantly limits their application.
The latest generation of tubes – a tube made of polypropylene. Compared to other tubing, polypropylene tubing have several advantages:
- Physical durability – guaranteed for 50 years.
- Polypropylene tubing do not require painting.
- Lower thermal conductivity – the lack of heat loss, which makes it possible not to apply the insulation of tubing. As a consequence – no kondensana on the outer walls of the tube.
- Energy saving in transport in polypropylene tubes of hot water is from 10 to 20%, compared to metal.
- Depending on the operating pressure of the carrier temperature can reach 95 ° C, as well as possible short-term increase in temperature to 100 ° C.
- Light weight, it can be easy to carry and install. Weight polypropylene piping in 7-9 times less than the weight of a similar pipe, mounted in metal structures. The total installed cost is less than that of tubing and fittings made of other materials.
- Lack of electrical conductivity (not conducting stray currents).
- Lack of chemical attack (no galvanic couples), thus avoiding the narrowed inner pipe diameter and pipe capacity decreases with time
- Easy installation – installation with polypropylene tubes 2-4 times faster than steel, but it’s more objects, more orders.
- Not susceptible to limescale due to smooth inner surface.
- Not susceptible to acids, solvents and other chemicals.
- The absence of bacterial flora. Polypropylene is chemically resistant and does not affect the quality of the transported water.
- Acoustic insulation (there is no resonance in connection with the flow of water and the noise of water hammer).
- Reducing the flow resistance due to smooth inner surface.
The best material for polypropylene pipe is polypropylene polymer – random type 3 (RRR 80). It is lightweight and durable polymer belonging to the category of thermo PEX . It is chemically resistant to most solvents – how acidic or alkaline type. Of particular interest is the universality of the thermal polypropylene tubes from it operated at temperatures from -10 ° C to +90 ° C. Briefly pipe can withstand temperatures of up to 100 ° C. Due to the elasticity of the material, the water in polypropylene tubing can freeze without destroying them.
This copolymer was obtained by modifying the structure of polypropylene, that is adding to its molecular chain of the ethylene molecule, which improves the mechanical properties of polypropylene (viscosity, elasticity, high strength).
Today, the world recognized that the random copolymer of propylene is most valuable. It is characterized by the highest strength and durability at high temperatures, which resulted in their widespread use in household utility networks. This is facilitated by the low thermal conductivity of the PPR. Its thermal conductivity is equal to 0.23 W / m * ° C.
PPR does not harm the environment. At its processing and disposal of waste is produced environmentally harmful substances. In addition, polypropylene is suitable for disposal without the addition of environmentally harmful substances.
Scope of polypropylene tubing
Polypropylene tubes can be used when installing internal sewerage systems, the organization of drainage system of soil and sewage and drainage of domestic wastewater (due to its high chemical resistance, toughness, ability to withstand high pressure and good welding properties.).
Polypropylene tubes are also used for domestic hot and cold water, sewage, floor heating and wiring central heating systems with temperatures up to +90 ° C. Each of these systems, their features, among which is very important water temperature and pressure. It is these values are critical in the selection of polypropylene tubing, so as greatly to their longevity.
For cold water (the temperature of the transported medium to +20 ° C) produced the pipe nominal operating pressure of 1 MPa – PN10 or 1.6 MPa – PN16; for hot water systems (temperature up to +75 ° C) and heat (temperature up to +90 ° C) nominal pressure of 2 MPa – PN20 and 2.5 MPa – PN25 (reinforced). In addition, the fittings are manufactured from polypropylene and composite parts having in its design, brass vpresovannuyu box with external or internal thread, which allows easy transfer from PP to the metal.
Sewer system serving the building as a small quantity (detached houses, small houses, cottages) and high-rise complex and multi-level, can be fully assembled in polypropylene tubes with socketweld connections and fittings for them
Polypropylene tubes can also be used for the transportation of compressed air and chemically aggressive environments. Each year, increasing their use of irrigation and drainage systems.
Installation of polypropylene tubing
Easy and quick installation and high quality connections is one of the main advantages of PPR-systems. Polypropylene tubes are tougher than PEX, and the systems are going through fittings: angles, tees, etc. Systems of RRR-pipe-piece.
Piping made of polypropylene compounds is performed by diffusion under the temperature of 260 ° C, otherwise it is still called fusion welding, which allows you to create a completely solid homogeneous connection. The welding process does not take long and consists of only three steps: cutting, heating, connection. In this connection can be put into operation immediately after welding. A reliability of welded joints – the highest in comparison with other methods and approaches the strength of the tubing themselves.
For the device of thin branches from the trunk with a large diameter, there are special fittings. For RRR-pipe joints with metal parts (valves, mixers) produce special fittings with pressed brass elements in them.
First of all you need next from this list:
- These being water pipes that are used for PEX plumbing, the pipes should be resistant to both the types of adverse temperatures to supply water throughout the house. If the pipes are not resistant to extreme temperatures then the water could freeze in cold weather and the water could get too heated up in hot weathers.
- The plumbing materials that are used for the construction should be flexible. This flexibility in the material makes it easy to fix the plumbing pipes to the house easily.
- The material used for the plumbing purposes should be tough, so that it can take the pressure internally and externally.
- Cost effectiveness should also be a parameter taken into consideration as we all have budgets while building the house
The above mentioned features are a few to be considered while selecting the best plumbing material. PEX is one of the lately introduced materials which has a very good advantage over the usually used metals and copper pipes. PEX tubing offers all the above discussed features that are required to be qualifies as the right plumbing material. But in case of metal pipes, one or the other characteristic is missing.
Plumbing with PEX is a very simple procedure. It can be done with the help of the expertise or can be done by you. This is because the pipes are flexible. Hence they can be tilted without any particular fitting at the corners. This avoids unwanted drilling in the walls. PEX plumbing is available in various sizes. Depending on the usage of the water, the right size is provided. The PEX pipe sizes range from 1-4 inches. Plumbing with PEX for residential use would need around 1 inch and higher for commercial purposes. PEX manifolds is also available in light colors to blend with your décor if partially visible. Thus PEX tubing tools has changed the entire idea of plumbing. It is now cost effective, durable and more flexible.