Features & Benefits over other pipes :

1 Inherent Corrosion Resistance
  • Long, maintenance-free service life
  • No add-on linings or coatings to damage, repair, inspect or maintain.
  • Hydraulics don’t change
  • Lowest Life Cycle cost
2 Smooth I.D.
  • Superior hydraulic characteristics
  • High flow capacity
  • Significant energy savings in pumped systems
3 Lightweight
  • Less expensive equipment for handling
4 Long Length Sections
  • Fewer joints to assemble
5 Resilient Inner Liner
  • Excellent abrasion and crack resistance
6 Computer Controlled Production
  • Consistent high quality pipe
  • Reduced risk with fewer problems
7 High Stiffness, Solid Pipe Wall with High Compressive Load Capacity
  • Easy to bury using routine methods
  • Predictable performance
  • Easily handles deep covers
8 Gasket-Sealed, Push-Together Joints
  • Fast, fool-proof assembly
  • No bonding agents, bolts or welding needed
9 Leak-free Joints
  • Zero infiltration, lower treatment costs
  • No ground water pollution
10 Smooth, Dimensionally Consistent O.D.
  • Field length adjustments easy – pipe may be cut anywhere along length and assembled with gasketed joint
  • Lowest jacking loads


Glass reinforced plastic pipes are made up from glass fibre reinforcement embedded in or surrounded by cured thermosetting resin. The composite may contain aggregate and granular as fillers.


GRP pipes are world-widely also known as

  • RTRP – Reinforced Thermosetting Resin Pipe
  • RPMP – Reinforced Plastic Mortar Pipe
  • FRE – Fibreglass Reinforced Epoxy
  • FRP – Fibreglass Reinforced Plastic


The different GRP Pipe manufacturing methods are

Filament winding

  • Reciprocal method
  • Continuous methods
  • Multiple mandrel method
  • Ring and oscillating mandrel method

Centrifugal Casting

  • Preformed glass reinforcement sleeve method
  • Chopped glass reinforcement method

Basic Raw materials used in GRP Pipe manufacturing are

  • Glass fibre (for reinforcement)
  • Resins (as a binder)
  • Other materials - Siliceous sand (fillers) and Additives for improving/modifying resin properties

Characteristics of the fibre glass composite pipes

Fibreglass pipe is a composite material system; so by selecting the right combination and amount of the materials and manufacturing process, the designer can create a product to meet most demanding requirements. (w.r.t. AWWA M45, 2.2)

General characteristics of GRP Pipes

  • Corrosion resistance
  • Strength to weight ratio
  • Light weight
  • Electrical Properties
  • Dimensional Stability
  • Low maintenance cost

Hydraulic characteristics of GRP Pipes

  • The smooth interior results in low fluid resistance, which could lower horsepower requirements for pump systems
  • The interior surface typically remains smooth over the time in most fluid services. Hence fluid resistance does not increase with age
  • Smoother interior allows the pipe diameter to be reduced while maintaining the desired flow
  • Inside diameter (ID) is typically larger than IDs of many other pipe materials of same nominal size and provide a larger pathway for fluid flow

various properties possessed by GRP pipes are –

  • Physical Properties
  • Mechanical Properties

Physical Properties

Chemical Resistance
All fibre glass pipes provide excellent resistance to water and native ground conditions. They are not subject to general corrosion attack, galvanic corrosion, aerobic corrosion, pitting, dezincification, etc. It may subject to environmental stresses and ageing effect.

Temperature resistance
For typical use in water supply systems fibreglass pipe is unaffected by service temperature. In colder or subzero conditions no significant effect observed on the performance of GRP pipes. The upper limit of the service temperature is influenced by the chemical environment, stress condition and the type of resin used.

Abrasion Resistance
GRP pipes provides generally good abrasion resistance and can be custom made for extremely abrasive services by providing silica flour / carborundum lining / ceramic bedding.

Flame retardants
Thermal stability of the GRP pipes can be improved by using resin systems that contains halogens or phosphorous, hydrated fillers, antimony oxide.

Weathering Resistance
Weathering studies have shown that structural integrity of the GRP pipe remains unaffected by exposure to UV rays. Any surface degradation can be controlled by adding UV stabilizers in the resin system used in the layer to be exposed.

Resistance to biological attack
GRP pipes does not deteriorate break down under the attack from bacteria or other micro-organism. No special engineering or installation procedures are required to protect GRP pipes from biological attack.

Mechanical Properties

The design flexibility inherent with glassfibre reinforced plastic material, fibreglass piping product standards are performance based rather than thickness property tables. Following table gives the range of mechanical properties available with GRP Pipe (w.r.t. AWWA- M45 Table 2.1)


Sr. No. Mechanical properties British unit SI Unit
1 Tensile strength 7000 – 80000 (psi) 50 – 550 MPa
2 Tensile modulus 0.5x106  - 5x106 (psi) 3.5x103  - 34.5x103 MPa
3 Flexural strength 10000 – 70000 (psi) 70 to 480 MPa
4 Flexural modulus 1x106 to 5x106 (psi) 6.9x103  - 34.5x103 MPa
5 Coefficient of thermal expansion 8x10-6 - 30x10-6     (in/in/ oF) 14x10-6 - 54x10-6  (mm/mm/ oC)
6 Specific gravity 1.2 – 2.3 1.2 – 2.3
7 Compressive strength 10000 – 40000 (psi) 70 – 280 MPa



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