Consumables and Spares for Steel Plants: Copper Mould Tubes, Bearings for Machinery, Spares for Control Fluid Purification Unit in Thermal Power Plants. We are supplying High Performance Filter Cartridges: Dry Filter Cartridges, Fine Filter Cartridges and Fullers Earth to various NTPC Units, through another independent profit center of the Group – namely, Rotring Engineering India Pvt. Ltd., which is a joint venture company with Bilfinger Rotring Engineering GmbH of Germany.