Horizontal Tank. Capacity 250 gallons. Wall thickness 0.212 in. Tank: 2 ft. 6 in. outside diameter, 7 ft. 7 in. length, 6 ft. 7 in. straight wall length. Legs: 4 ft. 2 in. center to center distance apart, 4 in. wide. Flanges are class 150 flanges. Top ports: Large flange is 6 in., middle flange is 4 in., small flange is 3 in. Bottom drain port is 1 in. FNPT. Overall Dimensions: 8 ft. 2 in. L x 2 ft. 6 in. W x 3 ft. 7 in. H.