Every steel tank is designed and manufactured at our factories, giving us both flexibility and control over quality and lead time. Because long-term tank integrity is absolutely essential for the reliability and long life of a transformer, Delta Star fabricates transformer tanks to meet the highest standards of quality and craftsmanship. All tanks and covers are fabricated of high quality plate steel to withstand full vacuum. Tank corners are bent instead of welded to assure strength, reliability, and eliminate stress leaks. Welding is accomplished in a double shielded "mig" process that provides continuous welds. All tank seams are welded inside and outside to ensure leak free construction.