GRP Water Tanks: What They Are, Types and Benefits
BM PROCESS · FAQ
GRP Water Tanks: What They Are, Types and Benefits
By the BM Process Management engineering team · Reviewed by our process and storage engineers · Last reviewed: September 2026
A GRP water tank is a storage tank made from Glass Reinforced Plastic, a composite of glass fibre and resin that is strong, lightweight and highly resistant to corrosion. GRP tanks are widely used to store water and other liquids in industrial, commercial and municipal settings.
This page explains what GRP stands for and means, what GRP tanks are used for, the main types such as panel, sectional, one-piece, cylindrical and insulated tanks, their benefits over steel, and how to choose the right industrial storage tank. BM Process advises on industrial water and liquid storage solutions.
GRP Water Tanks: Frequently Asked Questions
GRP tank meaning and basics
What is a GRP tank and what does GRP stand for?
A GRP tank is a storage tank made from Glass Reinforced Plastic, a composite of glass fibre and resin that is strong, lightweight and highly resistant to corrosion. GRP stands for Glass Reinforced Plastic, also known as fibreglass. GRP tanks are widely used to store water and other liquids in industrial, commercial and municipal settings, where their corrosion resistance and long service life are major advantages over metal.
What does GRP tank mean, and what is its full form?
GRP tank means a tank made of Glass Reinforced Plastic; the full form of GRP is Glass Reinforced Plastic. It is a composite in which glass fibres reinforce a plastic resin matrix, combining light weight with high strength and excellent corrosion resistance, which is what makes it well suited to liquid storage.
What is a GRP water tank used for?
GRP water tanks store potable water, process water, fire-fighting reserves and a range of industrial liquids. They are common in buildings, industrial plants, water treatment and utilities because they resist corrosion, are hygienic for water storage, and can be configured in many sizes and shapes to fit the site.
Is GRP the same as fibreglass, GRC or GRB?
GRP and fibreglass are the same material: glass fibres in a plastic resin. GRC is Glass Reinforced Concrete, a different composite in which glass fibres reinforce a cement-based matrix, and GRB is a common misspelling of GRP. For liquid storage tanks the relevant material is usually GRP; the similar initials cause frequent confusion, but the materials behave differently.
Types of GRP tank
What is a GRP panel or sectional tank?
A GRP panel tank, or sectional tank, is built from standard moulded panels bolted together on site to form a tank of the required size. This modular approach means the tank can be assembled in place, even where access is restricted, and sized precisely to the storage volume needed, which is a key reason panel tanks are so widely used for larger water storage.
What is a GRP one-piece or moulded tank?
A GRP one-piece tank is moulded as a single unit rather than assembled from panels, which suits smaller capacities and situations where a factory-finished, ready-to-install tank is preferred. It avoids on-site jointing and can be quick to install where access allows a whole tank to be delivered. For larger volumes or restricted access, sectional panel tanks are usually the better route.
What is a GRP cylindrical water tank?
A GRP cylindrical water tank uses a round cross-section, which is structurally efficient for holding liquid and common in both vertical and horizontal forms. Cylindrical tanks are often used where a moulded shape suits the volume and location. As with other GRP tanks, corrosion resistance and light weight are the main reasons it is chosen over metal.
What is a GRP insulated or cold water storage tank?
An insulated GRP tank has a built-in insulating layer to limit heat gain or loss, which helps keep stored water at a stable temperature and reduces condensation. GRP cold water storage tanks are widely used in buildings and facilities to hold potable or process water. The insulation is chosen to suit the climate and the duty.
What sizes and shapes do GRP tanks come in?
GRP tanks range from small one-piece moulded units to large sectional tanks assembled from panels, and include cylindrical, rectangular and insulated designs. Because panels are modular and moulded shapes are flexible, the tank can be matched closely to the required capacity and the available space on site.
Benefits, materials and what can be stored
What are the benefits of GRP tanks over steel?
GRP tanks resist corrosion without the coatings or cathodic protection that steel needs, are much lighter and easier to handle and install, offer good thermal insulation, and typically have a long, low-maintenance service life. For water and many chemicals this gives a lower lifetime cost than steel, particularly in corrosive or hygienic-sensitive duties.
Are GRP tanks corrosion resistant?
Yes. Corrosion resistance is one of the main reasons GRP is chosen for tanks. Unlike bare steel, GRP does not rust, and with the right resin system it also resists a wide range of chemicals. This makes corrosion-resistant GRP tanks well suited to water storage and to many aggressive liquids that would attack metal.
What can be stored in a GRP tank besides water, and are they suitable for chemical storage?
Beyond potable and process water, GRP tanks are used for fire reserves and, with the appropriate resin and lining, for a range of industrial and chemical liquids. GRP chemical storage tanks are specified for the particular service, because chemical compatibility depends on the resin system and any lining chosen to suit the fluid.
When would you choose a steel tank instead of GRP for industrial water?
Steel tanks can be preferred where very large capacities, high mechanical loads or specific fire and structural requirements favour metal, or where an existing site standard calls for it. The trade-off is that steel needs corrosion protection such as coatings or cathodic protection and is heavier to handle. The right choice depends on the liquid, the volume, the site conditions and the whole-life cost.
How long does a GRP water tank last and what maintenance does it need?
A well-specified and correctly installed GRP water tank typically offers a long service life with low maintenance, because the material does not corrode the way steel does. Sensible upkeep includes periodic inspection of the panels, joints and fittings, keeping the tank clean and hygienic where it stores potable water, and checking that seals and connections remain sound.
What is the difference between GRP tanks and GRP pressure vessels?
A storage tank holds liquid at or near atmospheric pressure, while a pressure vessel is designed and certified to contain contents under pressure and is subject to stricter design codes. GRP is used for both, but pressure-rated GRP vessels are engineered and certified to the relevant pressure standards, which is a different design task from an atmospheric storage tank. On higher-hazard duties this design work goes hand in hand with process safety studies.
Industrial storage and working with BM Process
What is an industrial water storage tank or reservoir?
An industrial water storage tank holds process water, potable water, fire reserves or other liquids for an industrial facility, sized to the plant’s demand and buffering needs. GRP is a common material because it resists corrosion and is easy to configure, though steel and other materials are used where the duty calls for them. The right tank depends on the liquid, the volume, and the space and access on site.
What are GRP tanks used for in water treatment and utilities?
In water treatment and utilities, GRP tanks store raw, process and treated water and support fire reserves and buffering, taking advantage of the material’s corrosion resistance and hygienic suitability for water. Their configurability lets them fit a range of plant layouts and capacities.
How do I choose the right GRP or industrial storage tank?
Selection depends on the liquid, the required volume, the space and access on site, and the design standards that apply, including whether it is a simple storage tank or a pressure-rated vessel. BM Process can advise on the right industrial water and liquid storage solution for your application; outline your requirements at https://bmprocess.nl/.
Can BM Process advise on industrial water and liquid storage?
Yes. BM Process advises on industrial water and liquid storage as part of its process engineering work, helping match the tank type, material and design to the liquid, the required volume and the site conditions. Because we look at storage in the context of the wider process, the tank is specified to suit how it will actually be used rather than in isolation.
About BM Process Management
Written and reviewed by the BM Process Management engineering team. BM Process Management is an industrial process engineering consultancy based in the Netherlands, advising on industrial water and liquid storage for industrial clients across Europe. The answers on this page reflect field experience in storage tank selection and process engineering.
