BUCHI SpeedExtractor E-916 - Manual (Page 69)

7 Maintenance
69 SpeedExtractor E-916/E-914 Operation Manual, Version D
7.3.2 Back washing
Back washing is an important maintenance procedure when not only pure and filtered solvents are
used such as for example buffer solutions.
The pump consists of two heads for alternate pump-
ing and purging. They are both equipped with a Luer
cone in the upper part, into which a plastic syringe
(P/N 034882) can be inserted as shown in the pic-
ture. Both heads are equipped with piston seals
(P/N 053612). When operating with buffer solutions,
there is a risk that buffer crystals stuck on the piston
might damage the seal, causing the pump to begin
leaking.
Therefore, after termination of the operation, it is nec-
essary to flush the lines and the pump vigorously with
clean solvent, which dissolves the buffer, and, at the
same time, to wash the rear part of the piston in the
purging head.