Double-grounded wall tank, and method of its manufacture

Double-grounded wall tank, particularly for storage of potentially explosive or highly combustible substances such as gasoline, other petroleum products, volatile hydrocarbon solvents, acids, alkaline solutions and the like, having

• a metal outer wall (11) which is electrically connected to ground;
• an inner wall (19, 21);
• and
• a spacer foil (15) separating the outer and inner walls and defining therebetween a test chamber (14) to permit pneumatic supervision of fluid tightness of the outer and inner walls, respectively,
• wherein, in accordance with the invention,
• the inner wall comprises a composite layer including
• a non-porous fiber-reinforced epoxy layer sprayed on the spacer foil spray-connected on the spacer foil (15) and bonded thereto;
• and an electrically conductive inner resin layer (21) spray-connected on the non-porous fiber-reinforced epoxy layer and bonded thereto, said electrically conductive inner resin layer (21) being positioned at the inside of the tank for contact with the substance to be retained therein and electrically groundable to prevent build-up of static electricity thereon.