Metal and Plastic Use in Piping Systems
Metal has been the favoured material used for parts in piping systems for centuries. Traditional metals that are used include copper and brass. Although lead was also commonly used up until the 1950′s, when their poisonous effects were discovered which resulted in the use of this metal being banned. Recent years have seen many developments in plumbing and piping technology, including the introduction of plastic piping fittings. Although their use was avoided by many at first, they are starting to become more and more common and are advantageous for a number of reasons. However, there are also a number of reasons why metal fittings shouldn’t yet be replaced completely.
The introduction of plastic fittings has resulted in a decrease in the amount of metal used in piping systems, as plastic carries a number of benefits. A plastic valve will never jam, stick or fail because of rust or corrosion – they are therefore considered low maintenance. Plastics corrosion resistance also positively affects flow rate – the inside of a plastic pipe is smooth and will stay that way year after year, resulting in lower pressure drops over time. Plastic is also much less expensive, both the fittings themselves as well as the installation, for example plastic fitting do not need pre-treatment with epoxy coating.
However, despite the numerous advantages of using the newer plastic fittings, there are still some reasons why the traditional metal piping fittings are better. Although advances in this area have been made, there are still currently no plastic fittings that can match the heat and pressure managing capabilities of those made of metal. Also, copper piping has a life expectancy of 75+ years and so is the best material to use in water distribution systems which are difficult to replace and a hassle to do regularly. As metal has been used highly effectively for centuries in piping systems, it is well trusted and the natural first choice that comes to mind.
In general, plastic fitting are considered an excellent alternative for a variety of piping requirements. They are cheap and low maintenance, have an excellent resistance to corrosion and are easy to install. However there are still a number of reasons why metal should continued to be used in many circumstances, for example water distribution where a long life expectancy is required. Also, metal is the only answer to problems involving high temperatures and pressure as there are currently no plastic fittings which can cope with these.