In a multistage vacuum
system, the vacuum line between the roughing pump
and the high vacuum pumps is called the foreline
. Vacuum systems are no longer exclusively used by scientists in research. They are used in numerous industries that range from food products to electronic components. The classic foreline is the hose or tube connecting a rotary vane pump and the outlet of an oil diffusion pump, although vacuum technology now uses a vast array of roughing pumps and high vacuum pumps.
The word foreline is not found in any dictionary although the term has been used for many decades by anyone working with high vacuum systems, and in literature concerning vacuum systems. It is not allowed in Scrabble at this time. The reasons for these omissions are unknown.
The foreline is mentioned in the brief introduction to the basics of the vacuum:
and in vacuum product FAQ lists: