API Spec 12P

This specification covers material, design, fabrication, and testing requirements for fiberglass reinforced plastic (FRP) tanks. Only shop-fabricated, vertical, cylindrical tanks are covered. Tanks covered by this specification are intended for above ground and atmospheric pressure service at various sizes and capacities ranging from 90 to 1500 barrels. Unsupported cone bottom tanks are outside the scope of this specification.

Standard designs are based on a maximum working pressure equal to the hydrostatic head of the stored fluid plus 6 in. of water column (0.217 psig) and 2 in. of water column vacuum. Design criteria are dependent on method of construction. Filament winding, chop-spray and combinations of these methods (commonly referred to as chop-hoop) are covered. Tanks constructed using hand lay-up (contact molding) are to be designed to the same standard as chop-spray construction.