High Pressure Error (EF 15) in the HP(TM)1090 Liquid
Chromatograph
The EF 15 error message from the 1090 indicates a blockage past the Damping Unit.
EF 15 – High Pressure Error
1. Ensure that the upper pressure limit in the method is set to a value suitable for the
analysis. (See procedure below to check for upper pressure limit).
2. Disconnect the column and check pressure.
A. If high pressure remains, go to Step 3 below.
B. If normal pressure is attained, install a zero dead volume fitting (part number
0100-0900) in place of the column (and precolumn/prefilter, if installed). If
normal pressure remains, the column is the source of high pressure. If high
pressure remains, look for a blockage in the system beyond the column.
Disconnect the tubing to the detector. If high pressure remains, replace this
tubing. If normal pressure is observed, disconnect the tubing coming from the
flow cell. If high pressure is observed, troubleshoot the flow cell for blockage. If
normal pressure is observed, check the waste tubing for blockage.
3. If high pressure is observed with the column removed, use the injector step
commands to switch the injection valve to the bypass position and monitor the
pressure. (See procedure below on how to change to the bypass or mainpass
valve positions).
A. If high pressure remains, go to Step 4 below.
B. If normal pressure is attained, the blockage is in the needle, needle seat
capillary, sample loop or rotor seal in the switching valve. Set flow=0. Switch
the valve to mainpass (flow through the needle). Use the step functions to lift
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needle (See below). Turn flow=1 and check pressure. If high pressure
remains, the blockage is in the sample loop or needle. Replace parts, if
necessary. If normal pressure is observed, set flow=0 and put the needle into
the needle seat. Remove the needle seat capillary tubing from port 5 of the
switching valve. Turn flow on. If high pressure is observed with flow going
through the needle seat capillary tubing, the tubing is blocked (see note
below). If pressure is normal, wrench tighten the needle seat capillary tubing
back into port 5 and remove the tubing from port 6 on the switching valve. If
high pressure is observed with flow going through the switching valve, the
blockage is in the rotor seal within the switching valve. Replace the rotor seal.
NOTE: If the blockage is found in the needle seat capillary tubing, in some
cases it can be recovered by backflushing. To backflush the tubing, remove the
tubing from the autosampler. Connect the tubing to port 2 of the switching valve.
With the autosampler in the mainpass position of the injection valve, increase the
flow to 4 ml/min in the pump and try to backflush the blockage out of the needle
seat capillary tubing. If steady flow can be pumped through the tubing, it has
been recovered. Replace the tubing in its correct position of the autosampler
(port 5 on the switching valve).
4. Disconnect the capillary tubing from port 1 of the 6-port switching valve. If high
pressure is observed, replace this piece of tubing. If normal pressure is observed,
reconnect the tubing to port 1 and disconnect the tubing from port 6. If high
pressure is observed, replace the rotor seal in the 6-port valve. If normal pressure
is observed, reconnect the tubing to port 6 and disconnect the tubing from the fitting
on the top of the column compartment. If high pressure is observed, check the
second piece of tubing coming into the column compartment and if pressure is
normal, switch to that piece of tubing. If pressure is high in both pieces of tubing,
call Agilent Technologies for an on-site repair to replace the Heater Assembly and
attached tubing. If pressure is normal, reconnect the tubing in the column
compartment and disconnect the tubing from the column/precolumn/prefilter. If high
pressure is observed, replace this piece of tubing going to the column.
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How to Switch the 6-Port Valve to Bypass
ChemStation Software
1. If not already displayed, pull down the View menu and select Method & Run
Control.
2. Pull down the Instrument menu and select Injector Diagnosis and Switch Valve
to Bypass.
3. The valve will switch to bypass.
4. Choose Switch Valve to Mainpass to switch to the mainpass mode.
1090 LUSI Keyboard
1. On the keyboard, press Shift, Ctrl, Shift, Alpha, I and Enter.
2. Type in STE=2 and Enter to switch the valve to bypass.
3. Type in STE=10 and Enter to switch the valve to mainpass.
How to Check for the Upper Pressure Limit specified in the Method
Using the ChemStation
1. If not already displayed, pull down the View menu and select Method & Run
Control.
2. Pull down the Instrument menu and select Set Up Pump.
3. Check the box Pressure Limits for the Max pressure setting. Ensure this value
is suitable for the application that is being run.
Using the Front Keypad of the 1090L
1. Press the Max Press key on the front keypad.
2. Enter the maximum pressure suitable for your application. Limits are 0
through 400 bar in steps of 1.
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How to Lift the Needle
Using the ChemStation
1. If not already displayed, pull down the View menu and select Method and
Run Control.
2. Pull down the Instrument menu and select Injector Diagnosis and select
Needle Up.
3. To put needle back into the needle seat, select Needle Into Seat.
1090 LUSI Keyboard
1. On the keyboard, press Shift, Ctrl, Shift, Alpha, I and Enter.
2. Type in STE=7 to lift the needle.
3. Type in STE=9 to lower the needle.
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