Double pipe heat exchangers are the simplest of all types. They are fabricated from two pieces of pipe – one inside the other. One fluid flows through the inner pipe while the second fluid flows through the annulus between the pipes
Advantages
•Inexpensive
•True counter current or co-current flow
•Easily designed for high pressure service
Typical Applications
- Single phase heating and cooling when the required heat transfer area is small.
- Can be used for heating using condensing steam if fabricated with elbows to allow expansion