Oil Storage Tank Grade Resin data sheet (PDF)Ask for a quote
What a tank lining is for
An FRP lining is a resin-rich laminate applied to the inside of a tank so that the stored product touches the lining, not the structure behind it. On a steel or concrete tank it separates the stored medium from a substrate that would corrode or contaminate it; on an FRP tank it is the corrosion barrier of the laminate itself.
The lining’s job is continuous contact, sometimes for years, with whatever is stored. That is a chemical question first and a mechanical one second.
Why the catalogue uses isophthalic chemistry here
Isophthalic polyesters are specified in Samrat Poly Resins’ SPR 301 family where a laminate faces water immersion or chemical service. The 2026 catalogue lists SPR 301 OT specifically for FRP lining of oil-storage tanks and for chemical-equipment manufacturing.
Its typical values — 300–600 cPs viscosity and 15–35 minutes gel time at 25 °C, specific gravity 1.04–1.14 and styrene 33–45% by weight — describe a laminating resin with a working window suited to lining work, cured at the reference condition of MEKP 1.5% with cobalt octoate 0.4%, each added separately.
“Oil” is not one chemical
Crude oil, diesel, furnace oil, lubricating oil, used oil and edible oils differ in composition, in the water and contaminants they carry, and in the temperature they are stored at. A lining that serves one well may not serve another the same way.
The catalogue does not publish a chemical-resistance chart or a maximum service temperature for SPR 301 OT. A recommendation therefore starts with the stored product, its temperature, how long it stays in contact and whether water separates at the tank floor.
How a lining is usually built
Corrosion-resistant FRP linings are commonly built in layers: a resin-rich surface layer reinforced with a veil, then chopped-strand layers, then any structural laminate. The resin-rich inner layer is the part in contact with the medium. The substrate preparation matters as much as the resin, because a lining that loses adhesion fails regardless of its chemistry.
Where a design standard governs the tank or equipment, its construction requirements apply to the finished lining, and should be named in the enquiry.