| 165 / | HD | HEAT EXCHANGE |
| DIG 163 | DD | INCLUDING A MEANS TO FORM FLUID FILM ON HEAT TRANSFER SURFACE (E.G., TRICKLE) {8} |
| DIG 168 | DD | .~ Film formed on interior surface of container or pipe {1} |
| DIG 169 | | .~.~ Inside of vertical pipe {1} |
| DIG 170 | DD | .~.~.~> Distributor "cap" mounted in top end of pipe |