GRP piping and steel cylinder concrete piping complement each other, and they both an important role to play in their relevant fields.
Piping made of glass reinforced polyester (GRP) has a high resistance to corrosion, which makes it particularly suitable for use in aggressive environments or fluids (industrial applications). However, use of this type of piping in water supply lines, irrigation and sanitation systems is becoming more common because of the competitive prices in medium sized diameters.
GRP pipes are classified according to their DN (nominal diameter), PN (Nominal Pressure) and SN (Nominal Stiffness) rates. These values are standardised in UNE-EN 1796, EN 14364, 2016 CEDEX Guide to GRP.
The advantages they offer are:
- Competitive price in the medium diameter range.
- Lightweight material making the pipes are easy to handle.
- Standard delivery length - 12 metres – enabling fast assembly.
Materials used in GRP piping
GRP (Glass Reinforced Polyester) piping consists of three main materials:
- A matrix made of an unsaturated polyester resin suitable for the type of fluid to be carried.
- Fibreglass reinforcement fitted inside the matrix.
- Inert material (generally quartz /dried silica), which fits into the matrix to give it structural strength.
Composition of GRP piping for water and sanitation lines
- Inner layer or barrier: this layer is designed to resist possible chemicals and abrasion, and to provide water-tightness as well as greater smoothness.
- Resistant or structural core: the intermediate layer provides the pipe with its mechanical strength.
- Outer layer: the aim of which is to provide resistance to external agents.
Pipes are joined together by means of sleeves. This system allows pipes to be cut to different lengths as needed. REKA elastomer seals are used for tightness.