PEX is a modified form of polyethylene. The cross linking of polymers within polyethylene strengthens the material. Due to the cross linking, it can now withstand a wide variation of temperatures from freezing point till about 200 degrees fahrenheit. It is also reinforced to withstand chemical corrosion and is flexible in nature.
Depending on your area of application, there are basically 3 types of PEX pipes to choose from. They include PEX-A, PEX-B, and PEX-C . Although all the PEX pipes are made through different processes, the structure of their composition is similar. PEX pipes are made through cross-linking polyethylene molecules to one another so as to achieve a resultant strong substance.
One major advantage that PEX pipes have over their metal counterparts is its flexibility, which makes PEX tubing installation considerably easier. PEX piping and fittings are easier to put together as there are no bends required when turning corners.
They can be used in conjunction with metal and pvc pipes. You can use PEX pipes for transmitting hot, as well as cold water. It expands and contracts under heat changes, reducing the chances of pipe burst and leaks. The installation of shut off valves at the supply lines with PEX tubing enables easy repair. These are some of the advantages that PEX has over conventional copper piping.
PEX's flexiblility and strength at temperatures ranging from below freezing up to 200 degrees fahrenheit makes it an ideal piping material for hot and cold water plumbing, service lines, hydronic radiant heating systems, snow melting applications, ice rinks and refrigeration warehouses.
PEX is manufactured and tested according to stringent national consensus standards: astm f 876, f 877, awwa c904 and csa b 137.5. Both the product manufacturer and independent third party testing agencies conduct routine quality control and quality assurance evaluations to insure the product meets astm, andi/nsf international and csa standards. Compliance with the standards ensures the end user of safety and quality. Aditionally, PEX is included in all of the major model plumbing codes used in the united states and canada: npc, upc, ipc and nspc, and approved by hud for hot and cold potable water plumbing use.
PEX is designed and tested to perform as well or better than any other material approved for hot and cold-water distribution systems. For indoor plumbing applications, PEX is expected to perform as long as any other approved plumbing distribution materials.
PEX tubing can be used up to 200 fahrenheit for heating applications. For plumbing, PEX is limited to 180 f. Temperature limitations are always noted on the print line of the PEX tubing.. PEX systems are tested to and can be used with standard t and p relief valves that operate at 210°f and 150 psi.
PEX tubing is not intended for outdoor applications and must be stored in a covered enviroment not exposed to direct sunlight. Refer to manufacture's instructions as to how long your pipe can have uv or sunlight exposure.
PEX plumbing and radiant heating systems can be pressure tested using water to check for leaks. Follow manufacture's instructions.
No. While PEX expands more than other plumbing materials, directional changes made with the tubing and some slack in the tubing during installation accommodate the expansion and contraction of the system if properly installed.
Yes. The flexiblity of PEX allows it to be supplied in coils meaning installations under the slab can be made in a single, continuous length without the need for fittings. PEX is not affected by concrete, (it is commonly encased in concrete for radiant floor heating). PEX , however, must be sleeved when penetrating a slab.
Yes, PEX saves money in many ways. For the installer, PEX tubing is competitively priced. Installation of flexible systems is fast because of the easy handling of the tubing and PEX installation requires fewer directional fittings.
No. PEX cannot be joined with solvent cement, glues or heat fusion. PEX is installed using only mechanical fittings or compression fittings.