Fast Guide to Materials

Introduction

Various types of plastics are used in plastic piping systems.

These plastic materials display a wide range of properties that make plastic pipe systems the ideal choice for anything from pressurised water mains to gravity sewer systems and indoor heating systems.

PVC, PE, PEX and PP are the four main types of material used in plastic pipes. These materials are found in a variety of pipe systems. ABS is used mainly in industrial pipe systems.

Light-weight, strength and flexibility are key characteristics of plastic pipes. Cost-effectiveness and a long service life are other advantages. Chemical resistance to many ordinary chemicals such as acids, bases, salts, and oxidants make plastic pipes suitable for a wide range of applications. Finally, plastic pipe systems are easy to install and require minimum maintenance.

 

PVC – The Most Widely Used Material

Polyvinyl Chloride or PVC is a thermoplastic material derived from common salt and fossil fuels. The pipe material has the longest track record of all plastic materials. The first PVC pipes were made in the 1930's. During the 1950's, they were used to replace corroded metal pipes and thus bring fresh drinking water to a growing urban population.

Further pressure and non-pressure applications in the field of sewers, soil and waste, gas (low pressure) and cable protection soon followed. The material's contribution to public health, hygiene and well-being has therefore been significant.

Based on the standard PVC material, three other variants are in use.
A high performance variant called CPVC is used specifically for indoor applications in hot water supply. 
Another variant called OPVC represents an important landmark in the history of plastic pipe technology. This molecular-oriented bi-axial high performance version combines very high strength with extra impact resistance. 

A ductile variant is the MPVC, PVC modified with acrylics or chlorinated PE. This very ductile material with high fracture resistance is used in high demanding applications where resistance against cracking and stress corrosion is important.

In several studies the long track record of PVC pipes has been investigated. Recent investigations at the German KRV and the Dutch TNO have confirmed that PVC water pressure pipes, when installed correctly have a useful life span of over 100 years. 

 

PE – A Wide Variety of Applications

Polyethylene or PE is a tough thermoplastic material derived from fossil fuels. PE piping is used for a broad range of pressure applications including the transportation of drinking water and natural gas, irrigation, sewers and drainage lines.

PE has been used for pipes since the early 1950's. PE pipe is made by extrusion in a variety of sizes dimensions. It is lightweight, flexible and easy to weld. Its smooth interior finish ensures excellent flow characteristics. Continuous development of the material has therefore enhanced its performance leading to rapidly increasing usage by major water and gas utility companies throughout the world.

The pipes are also used in lining and trench-less technologies, the so-called no-dig applications where the pipes are installed without digging trenches without any disruption above ground. Here the pipes may be used to line old pipe systems to reduce leakage and improve water quality. These ingenious solutions are therefore helping engineers to rehabilitate antiquated pipe systems. Excavation is minimal and the process is carried out quickly below ground.

Also for PE pipe material, several studies demonstrated the long track record with expected lifetime of more than 50 years. 

PP – A Most Versatile Polymer

PP is a thermoplastic polymer made from polypropylene. It was first invented in the 1950's and has been used for pipes since the 1970's.

Due to the high impact resistance combined with good stiffness and excellent chemical resistance makes this material very suitable for sewer applications. A good performance at operating temperature range from up to 60°C (continuous) makes this material suitable for in-house discharge systems Soil&Waste. A special PP grade with high temperature behaviour up to 90°C (short-term) makes that material a good choice for in-house warm water supply.

PEX – When Things Get Really Hot

Cross-linked polyethylene is commonly referred to as PEX. It is a thermoplastic material that can be made in three different ways depending how the cross-linking of the polymer chains is being made.

PEX was developed in the 1950's. It has been used for pipes in Europe since the early 1970's and has been gaining rapid popularity over the last few decades. 

Often supplied in coils, it is very flexible and can therefore be led around structures without fittings. Its strength at temperatures ranging from below freezing up to almost boiling makes it an ideal pipe material for hot and cold water installations, radiator and under floor heating, de-icing and ceiling cooling applications.

PB – Polybutylene – A High Temperature Material

A thermoplastic polymer made from butylene, which is derived from fossil fuel (oil, gas and coal). PB was invented during the 1950's and widely used in the 1980's and into the 1990's.


 

PB combines flexibility and strength at high temperatures and has found good use in hot and cold water installation.

PE-RT – Flexibility under any Temperature

Polyethylene of Raised Temperature Resistance or PE-RT expands the traditional properties of polyethylene. Enhanced strength at high temperatures are thus made possible through special molecular design and manufacturing process control.

Its resistance to low or high temperatures makes PE-RT ideal for a broad range of hot and cold water pipe applications.

ABS – For Industrial Purposes Mainly

Acrylonitrile-Butadiene-Styrene (ABS) is a thermoplastic material and was originally developed in the early 1950's for use in oil fields and the chemical industry. The variability of the material and its relative cost effectiveness has made it a very popular engineering plastic. It can be tailored to a range of applications by modifying the ratio of the individual chemical components.

They are therefore used mainly in industrial applications where high impact strength and rigidity are essential.

This material is also used in non-pressure piping systems for soil and waste.