Link points to Internet Archive / others. Not hosted by InfraLens. Details
IS 1521:2019 is the Indian Standard (BIS) for vertical steel tanks for petroleum products. IS 1521 covers large vertical cylindrical welded steel tanks for petroleum storage — the Indian equivalent of API 650. Used at refineries, fuel depots, and oil terminals for storing crude oil, petrol, diesel, and other petroleum products. Capacities range from 200 kL to 50,000 kL.
Specification for vertical cylindrical welded steel tanks for above-ground storage of petroleum products covering design, fabrication, testing, and foundations.
Both are vertical storage tank standards with similar scope. IS 1521 is the Indian national standard; API 650 is the international standard. Most Indian oil companies (IOCL, BPCL, HPCL) accept both.