This Information Applies To: Agilent GC Systems with Split/Splitless Inlet.
A leak may produce the following symptoms:
Steps to follow
If there is still a leak after the previous steps, then it means that there is a hardware leak. A good trick to half-split the system is known as the "septa sandwich." It isolates the septa assembly weldment and the electronic pressure controller (EPC) from the inlet body and split line, to help determine the location of the leak.
Septa sandwich Procedure for 7890, 8860, 8890
Figure 3: Squeeze these septa together to create a seal
Septa sandwich Procedure for 6890 and 7820A Gas Chromatographs
The preceding procedure is slightly different for 6890 & 7820A GC models. 6890 and 7820 GCs will require a change to step one where the removal of the top weldment must be done with the provided wrench or utilizing the flip-top that is installed on some 6890 systems. (See Figure 4)
Testing the split line
If the large stainless steel nut that holds in the split vent trap and the 1/8" brass nut that connects the copper split line to the inlet are done up tightly, then there is a small chance that the one of the valves in the split line has failed or stuck open. A quick test is to stick your finger against the split vent creating a seal (See Figure 5)
If the system pressurizes with your finger in the split vent, please call Agilent for service on your instrument.
If you still cannot determine where the leak is after following the preceding steps, contact Agilent Technologies.
Learn how to effectively maintain and troubleshoot your 8890/7890 Split/Splitless Inlet: