Chromatography Forum

Hello,

I'm installing a second inlet in an HP 5890 Series II GC. Its a split/splitless inlet with manual pressure control. I'm not getting any flow in the total flow or septum purge vents, and the head pressure gauge isn't registering any pressure. I was checking the fittings and noticed the solenoid valve is really hot to the touch. Is this supposed to happen, or do I need a new valve? Thank you for your time!

It could be the valve, or something in the electrics. Where is this valve in relation to the inlet ? upstream or downstream ?, in other words do you have back pressure or front pressure regulation (if front pressure you have some really old plumbing).

Peter

They can be hot when curent is being supplied. There is a "toggle" for the split vent valve on the control pannel. You should hear the valve clicking when toggling the control. If no then valve is most likley toast.

The valve is downstream of the inlet.

I'll try toggling the valve and listening for a click, thanks for the suggestion!

You may have a blockage between the inlet and the split outlet, and between the inlet and the pressure sensor, or upstream of the inlet. This would account for no flow through the split and no pressure. With back-pressure regulation the state of the valve makes no difference to the flow out of the split vent, it is only the route that the gas takes that changes when the valve opens and closes.

A massive leak is also a possibility - can you confirm that you have a column connected, or that the column connection is plugged ?

Connect an ordinary dial pressure gauge to a hollow needle and poke it through the septum to confirm whether you really do have no pressure or whether it is a sensor failure.

Peter