Fixed tubesheet heat exchanger.
This is a very popular version as the heads can be removed to clean the inside of the tubes. The front head piping must be unbolted to allow the removal of the front head, if this is undesired this can be avoided by applying a type A front head. In that case only the cover needs to be removed. It is not possible to clean the outside surface of the tubes as these are inside the fixed part. Chemical cleaning can be used. Shown is a version with one shell pass and two tube passes.