TCW Series Water Tank Heaters

Heating Tank Contents Without an External Loop

Some fluids should not be pumped out to an exchanger and back. They are stored rather than circulated, the volume is large relative to the flow, or adding a pump and pipework to a tank that already exists is unwelcome. A tank heater puts the heat transfer surface into the tank instead.

How it works. The bundle mounts on a flange that bolts to a tank nozzle. Hot water circulates through the tubes; the tank contents surround them. There is no shell in the usual sense, because the tank is the shell.

Natural convection sets the size. Most tank heating has no forced circulation on the tank side, so heat moves by natural convection and the coefficient is low. That is why tank heaters carry a lot of surface for a modest duty, and why the catalogued range extends to 120 inch lengths.

Storage water heating is the classic duty. A TCW in a storage tank, fed by a boiler loop, is one of the standard ways to make domestic hot water in a commercial building. The tank provides the buffer, the heater provides the recovery rate, and the two are sized together.

Removal clearance matters. The bundle withdraws back through the nozzle it entered, so you need clear space outside the tank at least equal to the bundle length. On a tank in a plant room or against a wall, that is worth confirming before the order rather than at the first service.