The main difference between Tube-in-Tube Heat Exchangers and Shell & Tube Heat Exchangers lies in their design. Tube-in-Tube Heat Exchangers consist of an inner tantalum tube and an outer steel or stainless-steel tube. This construction offers a compact design, which is especially effective for processes with low flow rates. Tube-in-Tube Heat Exchangers are easy to clean. The choice between Tube-in-Tube and Shell & Tube Heat Exchangers depends on the requirements of your process.