The word "PEX" in PEX plumbing is a term given to cross-linked polyethylene. This "cross-link" became possible through one of numerous processes that linked these polyethylene molecules to form bridges. Due to this, the material is known to be more durable under chemical attacks and temperature extremes. Aside from this, it can also resist creep formation. This makes PEX plumbing supplies the best materials for hot water as well as for other applications.

PEX has long since existed in the market. In fact, it was developed during the 1960s. In the US, PEX was introduced during the 1980s. Since its release, it has seen significant growth both in market demand and in market production. Even in most European countries, its use is not confined to PEX tubing alone. PEX is also utilized in radiant heating as well as snow melt applications.

PEX plumbing systems and supplies are known for their flexibility and strength, especially at temperatures that range from below freezing to 200 degrees F. For this reason, a lot of people are relying on PEX for their refrigeration warehouses, cold and hot water plumbing systems as well as service lines, snow melting applications, hydronic radiant heating systems and ice rinks.

Potable water plumbing applications have become easier with PEX. It can withstand low and high temperatures in most heating as well as plumbing applications. Moreover, it is highly resistant to the chemicals in most plumbing environments. It also offers flexible systems which seem quieter as compared to rigid piping. It has a smooth interior that doesn't corrode nor affect the long term pipe flow of other materials. PEX also has fewer joints and is freeze-break resistant. Furthermore, PEX is easier to install. This means, there are no worries over the cost of installation. Matter of fact, they're much cheaper than traditional plumbing materials.

Safety-wise, PEX plumbing and supplies are tested based on stringent national census standards. Product manufacturers and even independent third party testing agencies routinely conduct quality assurance and quality control evaluations. This ensures that PEX products meet "ASTM, ANSI/MSF International and CSA Standards".

PEX has several methods for connecting tubes and mechanical fittings. The two approved standard specifications for these PEX connections are the ASTM 1960 and the ASTM F 1807. Other fitting systems utilized are outside and insert diameter compression fittings. As a note, PEX can never be joined by heat infusion or solvent cement methods.

PEX plumbing systems and supplies are sized similar to how other CTS plumbing materials are sized. One good example is how CPVC is sized when utilized in a trunk-and-branch installation. However, PEX can also be sized in manifold systems. This way, it is guaranteed to meet the specific demands of every fixture, reducing energy as well as water wastage.

Size and packaging options available for PEX plumbing supplies are through ¼ inch to 1 inch CTS and it is packaged in 20 inch straight lengths or in coils. There are also PEX tubing products that are color-coded. For the coil lengths, they can go as long as 1000 inches though there are also much shorter lengths available.

There are minor disadvantages when using PEX. It cannot be used outdoors. This means, it cannot be exposed to direct sunlight. Also, it can't be recycled because of its short life span. If the pipes are left outside over a long period of time, they may get damaged.

Nevertheless, PEX has surmountable advantages as compared to these disadvantages. This is why most homes are still opting for PEX plumbing system and supplies.