English to Portuguese Science Petroleum Eng/Sci Crude Oil Refining and Distillation/E-learning

Contexto: Crude oil contains variety of hydrocarbons that have different boiling points. To separate these compounds, the oil is first heated and then fed into a distillation tower. The compounds with a lower boiling point rise up as vapors, while the compounds with a higher boiling point fall downwards as liquids.
The distilled products are then **pipped off** from the different levels of the tower.

Por favor qual a tradução correta para **pipped off** ?

Muito TIA