The GRP pipe wall is designed as a multilayer composite structure, with different layers providing corrosion resistance, structural strength, pressure resistance, ring stiffness and surface protection. The laminate construction is optimized according to the required nominal diameter, pressure class, stiffness class, service conditions and applicable design requirements.
Figure - GRP FW pipe wall structure
Internal liner layer
The liner, or chemically resistant layer, is the internal layer of the pipe. It is in direct contact with the conveyed fluid. This layer has the function of guaranteeing maximum resistance to chemical corrosion and securing the impermeability of the whole pipe. E-CFW manufacturing process incorporates separate resin feeding for the liner and structure. As a result, chemical-resistant resins can be incorporated into the internal liner for demanding applications, while the structural layers can be produced using standard-grade resin systems.
Structural Layers
It is the layer with a high content of reinforcing glass fiber that guarantees the mechanical resistance of the whole pipe to stresses due to internal and/or external pressure, external loads due to handling and installation, soil loads, traffic loads, thermal loads, beam loads, etc. The structural layer is obtained in different ways, depending on the manufacturing technology.
Outer Layer
The outer layer of the pipe has a minimum thickness of 0.3 mm as standard or more depending on the design requirement. It consists of resin and surface veil in order to protect the pipe mechanical layers from sun exposure and external impact.
GRP EFW pipes are suitable for a wide range of water, wastewater/sewerage, industrial, irrigation, desalination, energy & power generation, mining, subsea and many other applications, subject to the specified pressure, temperature, chemical compatibility and installation conditions. The composite construction provides high corrosion resistance, a smooth internal surface, low hydraulic friction, high strength-to-weight ratio and long-term structural performance. As well as EFW technology, GRP FW pipes provide a design flexibility to comply with challenging project conditions.