Fittings can be composed of many different materials. The old metal-only adage no longer exists and now materials can vary from copper to steel and even plastic and glass. What makes one material better than the other? There are many factors to take into account, including the expense of the material, its long-term durability, its ease of use and how it reacts to the environment it will be placed in. While stainless steel fittings might be perfect for one type of climate, they could be water damaging and corrosive in another. Knowing which material is best for each circumstance is the best way to get the most out of your fittings.
Copper fittings are widely used in domestic water services and distribution because they are not only durable and malleable, but they have a high level of corrosion resistance, good flow characteristics, require few fittings, and as an environment plus, they can also be recycled. PB or polybutylene is a plastic material used in fittings that are predominantly found in water supply pipes. The material is low cost, flexible, easy to install, frost resistant and is compatible with both hot and cold water.
However, PB needs to be protected from any UV exposure when used outdoors, or water could become contaminated. PVC-U, or unplasticised polyvinylchloride is found in fitting used on water supply and drainage pipes, and is very widely used due to its ability to be used in most every situation without the necessity for external protection, even underground or outdoors. PVC-U is durable, cheap, chemical-resistant, UV resistant, easy to install, has good flow characteristics and can be used for cold water, and hot water up to 60° Celsius.
PE/HDPE or Ployethylene, also known as alkathene or polythene, is often used for fitting well-water pipes. These fittings are durable, lightweight and flexible, inexpensive, easy to install, and have a good bending radius and good flow characteristics. They are also corrosion resistant. However, the main drawback to PE on a wider scale is the fact that it can only be used for cold water. PP, or Polypropylene comes in three different types.
P-H, PP-R & PP-B. All are chemical and corrosion resistant, lightweight and easy to install. All must be protected from UV exposure when used outdoors, however the main differences are that P-H is most commonly used for industrial sewerage waste pipe systems, PP-R is best used for domestic pressure water supply systems and PP-B is used most commonly in buried sewerage and wastewater drainage due to its high level of impact strength. PEX, of cross-linked polyethylene is made from a cross-linked, high density polyethylene polymer, making it stronger than in its original form. These fittings are extremely durable and chemical resistant, and can handle extreme temperature very well. PEX is also very flexible, easy to install and can be used for both indoor and buried outdoor situations. It is best not to use PEX in an exposed outdoor situation, as it is not UV resistant.
The choice of fittings varies for each project, but as its clear to see, due to their many properties, different materials work best in different situations. It’s always best to assess the situation first and find the best material for that purpose.