Oil Coolers are often baffles directing flow through the shell side so the fluid does not take a short cut through the shell side leaving ineffective low flow volumes. Oil Coolers are generally attached to the tube bundle rather than the shell in order that the bundle is still removable for maintenance.
Many oil companies however do not use single pass heat exchangers because they can break easily in addition to being more expensive to build. Often multiple heat exchangers can be used to simulate the counter current flow of a single large exchanger.Oil Coolers choice of tube material could result in a leak through a tube between the shell and tube sides causing fluid cross-contamination and possibly loss of pressure.
Oil Coolers current heat exchangers are most efficient because they allow the highest log mean temperature difference between the hot and cold streams. Oil Coolers requirements call for careful selection of strong, thermally-conductive, corrosion-resistant, high quality tube materials, typically metals, including copper alloy, stainless steel, carbon steel, non-ferrous copper alloy, Inconel, nickel, Hastelloy and titanium.