BOILER COVER FOR TRANSFORMERS Boiler Cover for Oil-Type Transformers High-Strength Hermetic and Expansion Tank Covers for 25 kVA to 10 MVA Power Ranges Usage Area: It is used in oil type hermetic or oil expansion tank type favor trusts and tawassul boilers with all power between 25 kVA, that is, 10 mVA. Material Type: It is produced from low alloy, high strength CCR 6112 sheet material. Sheet Thickness: Sheet thicknesses of all sizes between 5 mm and 10 mm are used. *P