Introduction:
GRP (Glass Reinforced Plastic) pipes are a new generation of the pipes with an industrial function and have been used in high percent of the local composite products recently.
The percent of handy composite producing and via fiber glass pipes were 63% and 34% in 1380 which changed to 43% and 48% in 1386 corresponding.
The process of producing the GRP pipes is a filament winding process which is achieved in 2 methods: Consistently and inconstantly.
In this process, the fiber glasses which have been covered by resin (mostly polyester) are twisted around a mandrel (tube form model) which increases the pipes' hoop stress.
Besides, the recovered sands are added during the process to increase the pipes' ring stiffness. The type of resin in different parts of the pipe (inside, middle and outside layers) usually depends on the moving fluid and the climate in which, this pipe is used. As the applied resin is termost, GRP pipes have a high insistence in the khorande conditions. The dimension range of these pipes is 100-3000 mm and their stress level is 6-32 bars. The other effective item to select these pipes is their ring stiffness (2500-5000-10000 N/m2).
These pipes because of some characteristics such as high insistence, longevity, and smooth inside surface and ring stiffness are used in several items as the below:
1- Water supply lines for the cities and villages.
2- abhay sathi transferring lines
3- Sewage transferring and collecting lines
4- Sea water transferring lines
5- Chemical fluids transferring lines
National and international standards:
National standards of Iran:
1- ISIRI 10729
Plastic- GRP which are useful in the under stress water supply installations- characteristics and test methods
2- ISIRI 10730
Plastic- GRP which are useful in the sewage transferring net- characteristics and test methods
3- ISIRI 11432
Plastic, GRP- characteristics and test methods
4- ISIRI 11433
Plastic- GRP which are useful in sewage collecting system and under stress industries pipes- characteristics and test methods
