PEX pipe & PEX Plumbing Reviews » Polymers

PEX tubing prices and promotions

admin — Mon, 17 Jan 2011 16:28:56 +0000

To get PEX tubing for low costs is not a difficult task. Even with no discount the prices for PEX tubing supply are considerably lower than prices for other materials used in piping. PEX tubing is thus cheaper than iron, and better than PVC due to its amazing resistance under pressure.

PEX supply stores generally offer PEX-a, PEX-b and PEX-c for sale. The low cost of these products differ only by obtaining methods. PEX-a and PEX-b might be cheaper than PEX-c, because the C method of obtaining PEX tubing uses high technologically advanced equipments. However, the prices can be lowered by a lot, if one knows where to look for them.

PEX tubing can cost less if one buys a large quantity of this material. Some people find this to be a great advantage, especially if they need it to replace the whole installation of the house.

But polymer pipes promotions have a disadvantage. Due to the fact that this material is so cheap, no too many producers are willing to change the prices for small quantities of polymer tubes. Apart from large quantities in purchase the only promotions one can find when purchasing polymer pipes is two in one offers. Meaning that, for the purchase of a polymer small quantity of materials, one can get to receive tools or another polymer tube, for free.

Another way to get a discount on polymer piping is to have a coupon from another product. Generally, related by niche companies initiate these types of promotions. As so, when a product from one of the companies is bought, the client receives a coupon that, presented in polymer stores gets him a discount on the polymer tubes he wants to buy.

The polymer materials are certainly cheaper than iron, and much stronger than PVC. Beside this, the polymer pipes look a lot better than the usual iron pipes, which might be quite an advantage for those that have to set their pipes on the outer walls. Iron pipes eventually damage causing rust to be spread out all over the walls and thus involving extra costs for wall reparations.

The bad part about all polymers is that, though it may be strong, it cannot be used for major pipes, such as the main house water pipe. In this case, high pressures can destroy the pipe in a matter of days.

Even so, for interior installations the polymer pipes and tubes are fully worth every penny paid for them.

Pipes metal-polymers

admin — Tue, 07 Sep 2010 19:40:56 +0000

Age metal pipes are much younger than the pipe cross linked polyethylene. The first metal-plastic pipes produced little more than ten years ago in England. The conventional designation of metal pipes – PEX – AL – PEX. New Development – PE – RT – AL – PE – RT (PEX – polyethylene, PE – RT – heat-resistant polyethylene, Al – aluminum) or PR – AL … for polypropylene. Metal pipe – essentially the same PEX – pipes, inside which establishes an additional layer of aluminum foil. The main purpose of installing foil – to reduce the coefficient of linear expansion PEX-pipes (this layer is also a diffusion barrier). Pipes made of metal-is a complex structure of five layers:

1. crosslinked polyethylene (REX or PE – RT) or polypropylene;
2. adhesive layer for a tight connection of plastic and metal;
3. overlapped or butt welded aluminum pipe;
4. gum;
5. crosslinked polyethylene, crosslinked polyethylene (REX or PE-RT) or polypropylene;

One of the advantages of metal pipes – the ability to maintain shape after bending, which allows their use in the open strip (PEX pipes installed just hidden). Apart from these, the main characteristics of metal pipes are as follows:
ability to withstand constant pressure (the pressure of 10 bar at 95 ° C);
physiological suitability for drinking water and food;

- 100% I impenetrability gases;
- Slight thermal expansion;
- Lack of structural changes and deterioration;
- Two types of pipe joints – pressing and Mapesil;
- Diameters of 16, 18, 20, 25, 26, 32, 40 and 50, 63, 75, 110 mm (in the system UNIPIPE).

The multilayer structure of metal pipes is a new word in the technique of montage. If their use does not have to think whether to use metal or plastic, because they use a combination of these materials. Supplied in coils or portions of various sizes virtually eliminates the need to cut pipes, but an exception of welding, threading or soldering faster and cheaper installation.

PEX: Peroxide technology

admin — Fri, 09 Jul 2010 19:00:43 +0000

Peroxides – some chemicals are activated with high temperatures, creating free radicals. The radical removes a hydrogen atom from the carbon atom in the chain of polyethylene, leaving the D-radical. This active molecule can connect with and form a similar relationship, ie crosslinks.
The most popular peroxide – 2,5-dimethyl-2 ,5-di-(butylperoxy) hexane. At room temperature – in the liquid phase, but can be adsorbed on a wide variety of surfaces. At high (180-220 ° C) temperature decomposes to form free radicals.
Peroxide is adsorbed on the lumps or rolls of polyethylene, then the mixture is fed into a cylinder with a piston, reciprocating, where he quickly melts (a process Thomas Engel). Passing through the usual spinneret PEX is formed in the PEX pipe. Continue heating the formed more liquid pipe leads directly to the reaction of peroxide crosslinking and performs its task. Most important in this process – to ensure the desired thermal profile, to prevent excessive crosslinking early in the barrel extruder, so that, in turn, prevent large losses. In such cases it is recommended to use special screws.
Only this technology (peroxide) has stitching in the molten phase. This ensures a random distribution of “stitches” stitching on the volume of the melt. The result is also a lower density of hardened material. It is fundamentally important temperature control. Typically, suppliers peroxide take it upon themselves to provide the necessary manufacturer of temperature-time zvisimostyami.
The maximum proportion of cross-linking determined by the amount of peroxide.

Durability of PEX materials to mold

admin — Wed, 07 Apr 2010 19:29:06 +0000

This technique of accelerated laboratory tests designed to characterize the effect of mold on the properties of PEX materials. This method also allows to evaluate the effectiveness of antimicrobial additives introduced into the plastic.

Test procedure is that the suspension is prepared spores from cultures that are most active when exposed to polymers. This method, if necessary, may also be assessed the influence of many different organisms. Preparation of suspensions spores used as a control material to assess the rate of growth of mold in the absence of a polymer sample. As a sample for testing, it can be any shape and size, including finished products, bars or parts of finished products. To study the effect of mold on the optical transparency or reflection using optically transparent samples.

Tests carried out in a petri dish or other suitable glass vessel, Pa bottom of which is placed nutrient salt solution agar. Then, on the inner surface of a spray applied suspension spores contaminated the samples is covered with a lid and placed in an incubator, the temperature which is maintained at 28-30 ° C and the humidity is not less than 85%. Samples aged in such conditions for 21 days. After that, visually assess the growth of mold.

To investigate the effect of mold on the physical, optical and electrical properties of the material, samples are washed from the mold and air-condition in accordance with accepted standard methods. Physical tests carried out by conventional methods and their results are compared with the properties of the control samples.