User manual

48 Bio-inert Quaternary Pump User Manual

4 Using the Pump

Hints for Successful Use of the Quaternary Pump

• Always place the solvent cabinet with the solvent bottles on top of the

quaternary pump (or at a higher level).

• When using salt solutions and organic solvents in the quaternary pump it is

recommended to connect the salt solution to one of the bottom gradient

valve ports and the organic solvent to one of the upper gradient valve ports.

It is best to have the organic channel directly above the salt solution

channel. Regular flushing of all MCGV channels with water is recommended

to remove all possible salt deposits in the valve ports.

• Before operating the quaternary pump, flush the pump and vacuum

degasser, see “Regular Priming” on page 43). This is especially

recommended if it has been turned off for some time (for example,

overnight) and volatile solvent mixtures are used in the channels.

• Prevent blocking of solvent inlet filters. Never use the pump without solvent

inlet filter. Prevent the growth of algae, see “Prevent Blocking of Solvent

Filters” on page 49).

• Regularly check the purge valve frit and column frit. A blocked purge valve

frit can be identified by a black or yellow surface, deposits or by a pressure

greater than 10 bar, when pumping distilled water at a rate of 5 mL/min

with an open purge valve.

• When using the quaternary pump at low flow rates (for example,

0.2 mL/min) check all 1/16-inch fittings for any signs of leaks.

• Whenever exchanging the pump seals the purge valve frit should be

exchanged, too.

• When using buffers or other salt solutions, flush the system with water

before switching it off. The seal wash option should be used when salt

concentrations of 0.1 M or higher will be used for long time periods.

• Check the pump pistons for scratches when changing the piston seals.

Scratched pistons will cause micro leaks and will decrease the lifetime of

the seal.

• Pressurize the system according to the wear in procedure after changing

the piston seals (see “Maintenance of the Pump Head” on page 126).

• Consider recommendations given in the solvent information section, see

“Solvent Information” on page 51.