GE AKTApure, User Manual, Page: 502 / 522

Recommended pressure control parameters
The table below contains the recommended values for P and I parameters for different media types.
Additional information Recommended
I factor Recommend-
ed P factor Column/Media
N/A 40 8 Default
N/A 40 8 Small soft media
columns
A higher I value than the default val-
ue is needed to speed up pressure
ramp-up times. 300 - 600 8 Large soft
1
media
columns
A lower I value than the default value
is needed to avoid large fluctuations
in pressure or flow rate. As an alter-
native, try increasing P. 15 8 Small rigid
2
media
columns
40 20
1
Soft media is defined as all GE separation media, except silica and MonoBeads.
2
Rigid media is defined as GE separation media that is based on silica and MonoBeads.
Back pressure
Using narrow tubing between components will improve resolution but will lead to increased back
pressure in the system. Narrow tubing after the column will increase the pressure in the column at a
given flow rate. Make sure that the pressure sensor limits in the system are set so that the maximum
pressure for the column used is not exceeded.
Additional instructions for avoiding pressure
alarms
The instruction Max flow during valve turn sets the maximum flow rate used during the turning of
the Injection valve and Outlet valve in order to avoid high pressure alarms. If the flow rate passing
through the Injection valve or the Outlet valve is higher than the set max flow rate, the valves will only
turn after decreasing the flow to the specified flow rate. After the valves have turned, the previous flow
rate will be restored. The instruction is found in System Control:System settings:Advanced.
502 ÄKTA pure User Manual 29119969 AB
9 Reference information
9.15 Pressure control