Hi Rebecca,
The brass circle through which the piston exits is in fact a sinter bearing - designed to hold oil (expert eye in our workshop, pers comm.).
Placing a drop of light machine oil on this got mine working again. I did the same preventative action for all other actuators in the lab too

Hope this helps

From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of Rebecca E. Plummer, Contractor, Code 6114
Sent: Wednesday, 4 May 2011 4:13 a.m.
To: [log in to unmask]
Subject: [ISOGEOCHEM] Conflo III - sticking actuator

We have a Conflo III, and the actuator that moves the Ref 1 capillary up and down is sticking.  As a result, when running N2 on/offs, my N2 reference peaks are sometimes non-existent, and sometimes just a quick spike.  The arm goes down in steps (not smoothly), and quite slowly (takes ~5 seconds to get all the way down), but comes back up as it should.  The ref 2 actuator is working fine, and CO2 on/offs look fine.  I've tried increasing the compressed air pressure, but that didn't help.  Is there any sort of maintenance I should try (lubrication, replacing seals, etc.), or is it likely that I need to replace the actuator?  Does anyone have advice on suppliers (It's made by SMC Pneumatics, model C85N8-25S)?  Thanks for your help.

Rebecca E. Plummer
Contractor, Code 6114
SAIC/Naval Research Operation
phone: (202)404-1736
fax: (202)404-8175
e-mail: [log in to unmask]