Tube in Tube Ammonia Heat Exchanger. Shell dimensions: 15 in. dia. x 69 in. L. Parallel flow with 6-passes. Each of the (6) tubes has spiral channels for improved heat transfer and flow. Encapsulated tube diameters: 6, 8, 10, 12, 14 in. Inlets: (2) 1 in. dia. NPT (female, ammonia), (1) 2-1/2 in. "S" line fitting product. Outlets: (2) 1 in. dia. NPT (female, ammonia), (1) 2-1/2 in. "S" line fitting product. Overall dimensions: 92 in. L x 26 in. W x 44 in. H.