Selecting Pipes for Plumbing

Plastic pipes stacked in a factory

A plumbing system is only as good as its components. No matter how well designed, a water network cannot be expected to operate safely and hygienically if the wrong products or materials are used. Likewise, if the best products are used but the installation is unsatisfactory, the system will be a failure or at the very least, not run efficiently.

To help you decide on the best pipes for your system, here is a guide on the ideal pipes for plumbing as well as tips on the actual selection process.

The Most Used Pipes in Plumbing

There are two general categories of materials for water pipework systems: metal and non-metal. The most commonly used are galvanised iron, copper, PE and CPVC.

  • Galvanised steel or iron

 

Galvanised steel or iron is the traditional piping material throughout the globe. Offering strength and durability, it can withstand high pressures making it an effective conduit for flowing water. However, it is declining in use for potable water due to corrosion. Electroplating technologies provide an external finish that helps prevent corrosion, but as the pipes have no internal protection, corrosion eventually occurs.

 

  • Polyethylene (PE) pipes

 

Polyethylene pressure pipes are thermoplastic pipes that offer impressive corrosion and fatigue resistance. Made of plastic, it requires a different joining method which results in leak-free joints that are as strong or stronger than the pipes. Because of its advantages, it has grown to become one of the world’s most widely used and recognised thermoplastic materials. PE pipes are generally grouped into three: high-density PE (commonly called HDPE), medium-density PE and low-density PE.

 

  • Copper tubing

 

Flexible and lighter than other metals, copper is also a favourite in the field. It is particularly useful for hot water supply systems. In the hands of a competent installer, integration into existing structures is easy. As a metal, corrosion can still be a problem, though to a lesser degree compared to galvanised steel. Plus, due to its electrical conductivity, utmost care is needed to ensure that the piping systems are separated from grounding connections and any electrical wiring.

 

  • Chlorinated polyvinylchloride (CPVC)

 

CPVC is widely used in water and sanitary systems. Like PE piping, CPVC is a thermoplastic widely used for water and sanitary systems. It offers good resistance to corrosion and has a high tolerance to acids. It is lightweight, non-toxic and odourless and reduces fungi, algae and bacteria growth. Having chlorine, it can withstand a wide range of temperatures.

Pipes and fittings made of plastic materials may cost more than those made of metal, but time spent installing, maintaining and replacing pipes is lessened with plastic.

Standards for plumbing products and materials

plumbing tools

Standards spell out the minimum quality, safety and performance of items to ensure uniform products and performance as well as the safety of installers, operators and the general public. They help installers reduce risk and provide assurance to owners.

Most industrialised countries have national standards that specify the minimum requirements for materials, design and use of products. Here in Australia, we have AS/NZS 3500.1:2018 or the Australian/New Zealand Standard Plumbing and Drainage. Should the need arise, companies can use international standards for enhanced durability, safety and performance.  

For drinking purposes, organisations can refer to WHO and other guidelines or standards that identify the maximum acceptable levels of metals and chemicals and other drinking-water supplies.

Plumbing materials lend their qualities to plumbing systems. In installing or repairing a plumbing system, equal consideration should be given to the types of plumbing materials and design.