To save some money, many people will go for a PVC pipe instead of a 3/4 PEX tubing. Beside the economical advantage, the PVC pipe also holds a disadvantage. Practically, these pipes can only be used for cold water. In hot water, the pipe can last for about 3 years and then crack. The PEX tubing however, is able to last for over 40 years in hot water and high pressures, so it is a much better investment than the PVC pipe. A PEX tubing is thus cost efficient in comparing to the PVC pipe, even though in the actual prices the PEX tubing is more expensive.
The PEX plumbing pipe system needs very few adjustments and replacing in time. Because of this fact, the PEX piping systems are mostly preferred not only for water installations around the house, but also for the heating systems. Outdoors, the PEX piping systems can be used only for smaller pipes. The PVC pipe is out of the question in these cases, because this type of pipe is unable to face cold or heat out in the open. However, the PVC pipe can last just as much as a PEX piping tube if kept in good conditions and no hot water runs through it.
When it comes to installation costs, the PEX plumbing pipe system is almost as expensive as the PVC. Generally, both types of installations require less effort than the iron installations, thus a plumber might charge less.
Both materials can be easily found online or on real stores, for similar prices. The PVC is only a few dollars cheaper than the PEX tubes, so the real expense cannot be considered unless purchasing for large quantities. However, fittings required for PEX as well the tools and equipments needed to install the tubes are considerable more expensive than PVC ones.

