WU Series Liquid-to-Liquid Heat Exchangers

Pumped Water in the Shell, Process Fluid in the Tubes

The WU is arranged for pumped liquid on both sides. Boiler water circulates through a baffled shell while the heated or cooled fluid passes through a removable U-tube bundle. Because both streams are pumped, shell-side velocity is a design variable rather than something the steam decides for you, which is why the shell carries baffles the SU does not need in the same way.

Both sides matter to the sizing. On a steam unit the condensing coefficient is so high that the water side controls. On a liquid-to-liquid unit neither side dominates automatically, so flow rate, allowable pressure drop and fouling on both sides all feed into the selection. Sending us only the tube-side conditions leaves half the problem unstated.

The classic applications are steady rather than dramatic. Pool and storage tower heating, condensate cooling, oil cooling and snow melting all appear in the catalogue descriptions, and they share a profile: modest temperature differences, long run hours and a strong preference for equipment that can be cleaned rather than replaced.

Free thermal expansion still earns its place. Even without steam, a liquid-to-liquid unit sees startup transients, seasonal swings and the occasional upset. The U-bundle absorbs all of it with no expansion joint to fatigue, and the bundle withdraws for shell-side cleaning when the water quality eventually leaves a deposit.

Part numbers and legacy designations. The 5-265 and 5-266 catalogue ranges cover the WU, and the older WU85-2 style designation describes the same units. Either form on a nameplate is enough to identify the unit, its shell dimensions and its pass arrangement.