1 Used Yula Stainless Steel Dual Service Heat Exchanger, Model WCV-6AA-33AAS. NB #: 12592. Manufactured in 2007. Specifications: Water to Water (U-Tube). Number of passes: 6. Shell size: 4”. Tube length: 33”. Tube size: ½”. MAWP: Shell and Tubes: 150 psi @ 350°F. MDMT: Shell and Tubes: 35°F @150 PSI.