Oval tanks Oval GRP tanks holding 600-10,000 l - made from glass fibre reinforced plastic, GRP - filling dome dia. 360 mm, with quick closing lid - filling dome dia. 420 mm with flap lid - ventilation valves fitted in the lid - outlet opening with 3-hole flange connection - fixed support runners attached (high pressure impregnated wood, above 7000 l - steel)