How Different Are FRP and GRP? In comparison to glass fibre-reinforced plastic

Written by Rahul Verma | Updated: February 12, 2026

FRP’s excellent resistance to corrosion has led to its increased application in the process, water, and chemical industries in recent years.

Water, oil, fuel, glycol, wastewater, sewage, etc. are all transported through FRP pipes at an increasing rate. Therefore, there is an ever-increasing requirement for FRP pipes.

Typically, the lifespan is in excess of 50 years. As a result, the lifetime cost of FRP pipes is less than that of metal pipes.

What exactly is FRP

Fibre-reinforced polymer is an abbreviation for a composite material made of a polymer matrix and fibre reinforcement. Therefore, a pipe made of FRP material by either the contact moulding or filament winding method is known as an FRP pipe. Specific FRP pipe qualities can be achieved by using different resins, such as thermosetting polyester, epoxy, phenolic resin, etc.

Glass fibre is the most popular reinforcing material. FRP piping systems are used all over the world as a corrosion-resistant alternative to metal piping.

Typical Fibers are:

Glass, when combined with a matrix to create fibreglass or glass-reinforced plastic, is an excellent insulator. It’s not as tough or rigid as carbon fibre, but it’s also not as fragile or pricey.
Carbon-based fibre-reinforced polymers include minimal thermal expansion and weight in addition to good tensile strength, chemical resistance, stiffness, and temperature tolerance. Most of the carbon atom crystals in a fibre will be aligned with its long axis. By increasing the strength-to-volume ratio, this orientation strengthens the material.
Strong and resistant to high temperatures, synthetic fibres made with aramid are produced. It’s useful in a wide variety of fields.

The necessity for internal lining, external coating, and cathodic protection is readily eliminated when FRP is used for pipe and fittings, such as flanges, elbows, tees, crosses, reducers, etc. The sizes of FRP pipe systems range from 1 inch to over 100 inches.

Not limited to FRP piping systems

FRP is used to make a wide variety of products, including pipelines, storage tanks, towers, grids on walkways, profiles (similar steel profiles), etc. Here’s how a storage tank works:

Introduction:

There are two types of FRP storage tanks: vertical and horizontal. When choosing a material for storage tank windings, it’s important to keep appropriateness, quality, and cost in mind.

FRP-wound storage tanks typically have an inner liner layer, strength layer, and outer surface layer making up the tank wall structure during construction.

Choosing the right resin and materials

The inner liner is in direct touch with the medium and, depending on whether or not the material selection is correct, is crucial to the success of the wound storage tank’s leakage control.

The inner liner is made of surface felt that has been chopped together to reinforce in order to increase the amount of glue and enhance the impermeability; the vinyl resin is used if the medium being stored is acidic; bisphenol A resin is used if the medium being stored is alkaline; alkali-free glass fibre is used if water and alkali resistance is required; medium-alkali glass fibre is used if acid resistance is required.

The storage tank’s strength and stiffness requirements are largely met by the strength layer. Since the outer surface is in direct contact with the external environment and the material is chosen based on the ageing resistance requirement, care must be taken when selecting the resin matrix to ensure it can be easily penetrated by the glass fibre used in the winding process, thereby creating a dense structural layer.

Application:

A wide variety of media can be safely stored in FRP tanks. Pressure, corrosion, age, lightweight, high strength, impermeability, heat insulation, insulation, non-toxicity, and smooth surface are just some of the benefits you’ll enjoy with these products. It finds use in numerous fields, including coatings, medicines, construction materials, chemicals, pigments, resins, food, and scientific research.

FRP’s Disadvantages

Fluids hotter than 100 degrees Celsius should not be transported in FRP.

Pigments, dyes, UV stabilizers, fillers, etc., added to the resin system, can slow the degradation caused by sunlight.

A Few FRP Codes and Standards

Contact-molded “Fiberglass” (Glass fiber-reinforced thermosetting resin) corrosion-resistant pipe and fittings are standardized by ASTM D6041. Obtaining Hydrostatic or Pressure Design Basis for Fiberglass (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe and Fittings, ASTM International, West Conshohocken, Pennsylvania, D2992. ASTM B31.3 Process Piping, West Conshohocken, Pennsylvania. A.S.M.E., Big Apple
Flanges made of glass-fibre reinforced thermosetting resin according to ASTM D5421, the standard specification for contact moulding. ISO 7370, West Conshohocken, Pennsylvania ASTM, Pipes and fittings made from glass fibre reinforced thermosetting polymers (GRP) – Nominal, specified, and standard diameters and lengths
ANSI AWWA C950-2020, For both above- and below-ground water systems, this standard details the manufacturing and testing of fibreglass pipe and connecting systems with nominal sizes ranging from 1 in. (25 mm) to 156 in. (4,000 mm). Pipeline systems for both service and distribution, as well as transmission, are included.
AWWA M45, Fiberglass Piping for Drinking Water Systems: Selection, Installation, and Maintenance
ISO 14692-1: Glass-reinforced plastics (GRP) pipes for the oil and gas sectors.