Non-metallic materials are used in non-critical services such as water and drainage, where operating pressure and temperature are not significant. In this lecture, I will give you an overview of these materials.
Commonly used non-metallic piping materials are
- PVC / CPVC
- And Cement pipes
These non-metallic materials offer some great advantage over metallic piping but also have some limitation. They are resistant to chemical attack but poor in strength.
PVC / CPVC
- PVC – is Polyvinyl Chloride and
- CPVC – Chlorinated Polyvinyl Chloride (that is having a higher strength at elevated temperatures than PVC)
- PVC and CPVC are tough and exceptionally resistant to chemical attack
- PVC and CPVC required protection from ultraviolet exposure if installed outdoor and start softening when subjected to high temperature.
- PVC/CPVC Pipes are made by Extrusion process
- And Fittings, flanges and valves are manufactured by injection molding method
- PVC has many applications in industries and it’s also used in home water piping.
- High-Density Polyethylene has many desirable qualities over LDPE and PVC,
- It has improved tensile strength
- Improved low-temperature brittleness
- Higher softening point
- Higher chemical resistance
- HDPE pipes are manufactured by extrusion process
- It is widely used in water distribution and low-pressure natural gas services
- It also used as lined material with carbon steel pipe
GRE/GRP pipes are getting popularity in sea water and sewage transport applications. These pipes offer excellent corrosion resistance property over all other types of pipes. The main difference between the GRE and GRP is the resin used for bonding the glass fiber.
GRP pipe used Isophthalic Resin whereas GRE pipe used Epoxy Resin.
- GRP that is Glassfibre reinforced plastic are used in
- Water supply application, Wastewater / Sewerage collection and sea water transport application
- GRE that is Glassfibre reinforced epoxy
- Pipes are used for industrial application, as it can withstand higher temperature compare to GRP pipe.
- GRE pipes are used in the offshore platform and water treatment plant to handle salty water.
- Due to Excellent chemical and corrosion resistance, it also used as lining material in sewage effluent tanks
- GRP/GRE pipes are manufactured using the filament winding process.
Cement Pipes are not used for any process application. However, it is used in process facility for various other purposes
- Cement pipes are manufactured from reinforced or non-reinforced concrete
- They mainly used in storm water and gravity services
- They also used in culverts and irrigation application