| 165 / | HD | HEAT EXCHANGE |
| DIG 355 | DD | HAVING SEPARATE FLOW PASSAGE FOR TWO DISTINCT FLUIDS {7} |
| DIG 400 | DD | .~ Shell enclosed conduit assembly {4} |
| DIG 401 | DD | .~.~ Including tube support or shell-side flow director {5} |
| DIG 403 | | .~.~.~ Preheater for shell-side fluid for preventing thermal shock to tube sheet |