The leak is at the seam or union -where the two guard column holder pieces
thread together.
The ferrules/bushings do not have leak problems.
Despite tightening the pieces as hard as I can, eventually the white crusty
stuff comes back through the theads. The weird thing is that when the
pieces are newly replaced and a leak test is done on the hplc system from
the guard column back to the pumps, it passes with flying colors. Yet the
leak sometimes appears within a day or two in some instances. I always
check the seals once removed and there always appears to be a slight
deformity, dent or something. But again, I've seen this from seals that
both engineers and I have replaced. Also, I very carefully inspect the
installed seals before putting them into the holder, then after installing
them (before putting the guard column in place). I can't figure this one
out and may resort to wading up teflon tape around the blasted thing unless
some one has a better idea.
regards! -margie
-----Original Message-----
From: Joseph Fernandez [mailto:fernaj@rockvax.rockefeller.edu]
Sent: Tuesday, January 26, 1999 3:08 PM
To: Margaret Whitton
Subject: Re: Prot Seq: leaky guard column
Margaret,
Is the leak at the union of the two holder halves, or where the
ferrule/bushing connect to the holder. Our Procise has had no leak
problems, and we still have the 4 year old gurad holder and seals.
Joe
>Dear Fellow protein sequencers,
>
>I've been having trouble with my guard columns leaking on my 492 Procise
>for sometime now. Whenever I replace a guard column, I must replace the
>guard column seals (the newer, dark-colored ones) at the same time or
>I'll always get a leak. When I change the seals and guard column
>together, they usually hold at first (and I check it constantly for
>leaks) but... sure as the sun will shine, over time the leak returns (as
>indicated by white crusty build-up in the seam of the guard column
>holder). The column pressure on my system reads normal so I don't think
>it's column back pressure causing the leak. I have tried many ways to
>fix it. I've replaced the guard column holder about 5 times with no
>success (as recommended by tech support & service engineers). I've
>tried different lots of seals. I've tried some of the older white
>seals. I've tried different lots of guard columns and, while I may get
>a temporary fix, it seems over the course of a few weeks to 2 months the
>leak comes back. I thought maybe I was replacing seals incorrectly, but
>my service engineers have replaced them on several occassions with the
>same results -eventually a leak. I believe this weak spot is the
>source of erratic dips that I see in my baseline which is especially
>problematic for low level samples. I have not been able to resolve this
>problem for about a year. I'm wondering if anyone has any helpful hints
>regarding this frustrating problem. Thanks.
>
> --Margie
>
>Margie Whitton
>Parke-Davis Pharmaceutical
>Division of Warner-Lambert
>Ann Arbor, MI
>Margie.Whitton@wl.com
>734-622-2807
Joseph Fernandez
Associate Director
The Rockefeller university
Protein/DNA Technology Center
1230 York Ave. New York, NY 10021
Phone: (212)-327-8869
FAX : (212)-327-8620
email: fernaj@rockvax.rockefeller.edu
Lab Web Page: http://pdtc.rockefeller.edu