PEX is the common name given to a form of polyethylene tubing that can maintain its strength and is resistant to dissolving at temperatures up to 1500C. As such, Pex pipe systems are the first to be truly suitable for use in both domestic cold and hot water systems.
In recent years the use of Pex pipe has become popular because it can be fitted in one continuous length, it is highly flexible and with the price of metals, and copper in particular, soaring it is becoming a much cheaper material to buy.
Using a Pex Pipe System for Hot and Cold Water Supplies
In the past, if you wanted to get hot and cold water feeds to a particular location you would have had no choice but to use Copper piping. The chances that at some pint you would need to route the piping around a bend or under floor-boards etc; inevitably meant that you would have to create a joint between two pieces of Copper.
Even if you were only installing a cold water feed and plastic piping – you’d still need to create joints. Probably the single most effective reason for using a Pex piping system is that, providing you have a long enough length of Pex piping, you do not need to create any joints between the source of the hot or cold water supply and the fitting that it is feeding.
Allowing for the curvature required when bending any ‘round’ profiled material, Pex piping can be bent around 90 degrees, or indeed any other angle. Alternatively, if the space in which the Pex pipe has to turn is a very confined one not allowing for the natural curvature, you can fit 90 degree adaptors to the pipe; to effect an immediate 90 degree turn.
Pex Piping in Radiant Heating Systems
As well as being used to feed hot and cold water to sinks and baths etc; Pex piping can also be used to transport hot water in radiant heating systems. If the radiant heating system has ferrous parts to it; a special Pex pipe with an oxygen barrier lining is required to prevent rusting.
Otherwise standard Pex piping can be used. Where an oxygen barrier is required a layer of Aluminum is sandwiched between two layers of Pex. This Pex piping system is known as Pex-Al-Pex. Being a plastic and flexible, Pex piping and Pex-Al-Pex piping is particularly suitable for under-floor heating systems that use hot water.
Pex Piping Accessories
Whilst its history goes back to the 1930s, Pex piping has only been on the open market for about 20 years. It is usually sold in coils up to 300 feet long and is available in a variety of diameters from 3/8 inch to 1 inch. 3/8 inch being used for radiator systems, ½ inch and 5/8 inch for under-floor heating and, of course, 1/2 inch being used for domestic hot and cold water supplies.
Should you need to connect lengths of Pex piping together there are male and female brass connectors; as well as brass manifolds to allow one feed line of Pex piping to support several others. Should the need arise, in a confined space, brass male and female elbow joints are amongst the other accessories available and, of course, there are fittings to connect the Pex pipe to a water supply. Pex pipe can be easily cut with a Pex pipe cutter and all the brass fittings attach to the pipe with a Pex pipe pressing tool.