Glass fiber reinforced plastic (GRP) storage tanks are commonly used in the chemical and oil industries because they are lightweight, durable, and resistant to corrosion. Here are the general steps involved in the manufacturing process:

Design: The design of the GRP tank is based on the intended use, capacity, and environmental factors. The tank design includes the shape, size, and specifications of the materials to be used.

Material selection: The materials for making GRP tanks include resin, catalyst, fiberglass mats or woven roving, and additives such as pigments and UV inhibitors. The choice of materials depends on the tank design and intended use.

Mold preparation: A mold is created from a negative of the tank design. This is typically made from steel or other metal, and it is polished and treated to ensure the release of the finished tank.

Laying up: The process of laying up involves applying the layers of fiberglass and resin to the mold. First, a gel coat is applied to the mold to form a smooth, protective outer layer. Then, alternating layers of resin and fiberglass are added, building up the thickness and strength of the tank.

Curing: The tank is then cured, which is the process of allowing the resin to harden and bond with the fiberglass. Curing can be achieved through various methods such as ambient temperature, oven, or post-curing methods such as hot water bath, which can enhance the mechanical and physical properties of the tank.

Finishing: Once the tank is cured, it is removed from the mold and any excess material is trimmed. The tank is then sanded and polished to achieve a smooth surface.

Assembly: The final stage of manufacturing involves assembling any additional components such as manholes, nozzles, ladders, and supports, as required by the tank design and specifications.

Overall, the manufacturing process of a GRP tank requires skilled workers and specialized equipment, such as spray guns, choppers, rollers, and vacuum pumps, to ensure the quality of the finished product.