Chromatography Forum

Hey all--

I have a leak that forms right above the injection valve of my Agilent 1100 system of which is not under warrenty. I already blew air through the lines in case the leak was being caused by a clog. That worked for about a day and now I am back to not being able to get any work done. Any suggestions? Does a seal need to be replaced somewhere? Any idea on the product number for a seal?

Thanks so much in advance for your help!

I have a leak that forms right above the injection valve of my Agilent 1100 system

At least for me, you'd need to supply more information.

(1) Do you mean the six-port injection valve? There's a rotor seal inside, both Vespel and Tefzel are available. Yes, these do wear out, and also can clog up over time with wear particles, causing high pressures (if so, clean out all the innards). You could try tightening the three Allen screws to see if that stops the leak. We stock spare rotor seals.

(2) Do you mean the metering valve on the upper right, which determines how many microliters get injected? That has the same piston and piston seal as the 1100 pump, and that may need replacing every few years, lasts considerably longer than a rotor seal. The fittings into that are standard stainless steel ferrules. We stock spare pistons and seals.

(3) I doubt you mean a leak where the needle inserts into the seat, but leaks can occur there as well. We stock a spares.

(4) I've also seen leaks in the coiled capillary tube from the metering valve to the needle, where the larger ends are welded on. We stock a spare one of those.

A couple of more options, although I'd probably need a little better description of exactly where and when you see the leak.

1) Is the valve waste tubing plumbed properly into waste?

2) Is the connection between your needle and sample loop leaking? This is fairly common place for a leak, which is why I'm not a fan of the Agilent microbore tubing with the very thin O.D.

3) I believe the waste channel for the component stacked above your autosampler is also directly above the injection valve, could that component be leaking?

Russell Nelson