4 1/2 in. OD x 120 in. long Tube Length (approx.), Main Shell is Carbon Steel, Tubes are Alloy 20 Material of Construction, MAWP-150/FV psig @ 350 Design Temperature, MDWP 55 F @ 150/FV psig, Tube: MAWP 150/FV psig @ 250 F Design Temperature MDWP -20 F @ 150/FV psig, Insulated with Metal Cladding Exterior, Piping and Valve Manifold and Instrumentation; Co. No. ME221B.