Introduction
Glass-reinforced plastic (GRP) pipes are a versatile material used across water, sewerage, and industrial piping applications. Strong, durable, and corrosion-resistant, GRP is a solid choice for long-term use in harsh environments.
A GRP pipe’s material and thickness both matter a great deal for performance. The material determines strength and durability, while thickness determines pressure resistance.
Material Selection
There are two main types of GRP pipes: polyester and vinyl ester. Polyester pipes cost less than vinyl ester, but are also less strong and durable. Vinyl ester pipes cost more, but deliver greater strength and durability.
Choose the material based on your application — polyester pipes often suit water and sewerage applications, while vinyl ester pipes suit industrial applications needing higher strength and durability.
Thickness Selection
A GRP pipe‘s thickness is determined by its pressure rating — the higher the rating, the thicker the pipe needs to be.
Pressure ratings are typically specified in pounds per square inch (psi). Here’s the minimum thickness required for GRP pipes at different pressure ratings:
| Pressure Rating (psi) | Minimum Thickness (mm) |
| 100 | 2.5 |
| 200 | 3.2 |
| 300 | 4.0 |
| 400 | 4.8 |
| 500 | 5.6 |
Conclusion
A GRP pipe‘s material and thickness both matter for performance — choose material based on the application, and thickness based on the pressure rating.
Additional Considerations
Beyond material and thickness, weigh a few other factors when selecting GRP pipes:
- Diameter: should meet the application’s flow requirements.
- Length: should meet the application’s design requirements.
- End fittings: should match the application and the pipe’s material type.
GRP pipes come from a variety of manufacturers — when selecting one, choose a manufacturer that meets your application’s quality standards.