Hi Anne.  I had the same problem about a month ago.  It was recommended
that I try lubricating it with a drop of light machine oil or a very
small amount of silicone grease.  In our case, this improved the
performance for a day, then it slowed again.  I ended up ordering a new
actuator (only $21.50!).  Here is a link to the product.
http://www.smcpneumatics.com/C85N8-25S.html
It was pretty simple to replace, and seems to have resolved the problem.
Good luck.

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

-----Original Message-----
From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On
Behalf Of Fname Lname
Sent: Wednesday, June 15, 2011 2:11 PM
To: [log in to unmask]
Subject: [ISOGEOCHEM] piston actuator sticking on ConFlo III

I forgot to mention that I am using Isodat NT version 2.0!
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Anne M. Cotter
U.S. Environmental Protection Agency
Mid-Continent Ecology Division
6201 Congdon Blvd
Duluth, MN 55804
218-529-5183
fax 218-529-5003
[log in to unmask]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~





My reference gas 1 piston actuator in the ConFlo III is sticking. When I
turn the port on, the piston slowly moves down into the thimble
sometimes stopping about 5mm from the endpoint. I have exercised the
piston which seems to have helped but it still doesn't move as smoothly
as the others. I also removed the capillary from the thimble to see if
the capillaries were making it bind but this was not the case. I also
checked the compressed air pressure and found it set to 3.75bar which
should be fine.
		 SO, can I use silicone grease on the piston to make the
piston
glide more smoothly or is there something else I should be doing?

The reason I found this problem is during the sample last run my
reference peak kept getting shorter in duration, from the routine 20
seconds to as short as 4.5 seconds. However the amplitude was always the
same. Also, some of my sample 13N values were not calculated due to this
shortened peak. I have tried to move the retention time of the reference
to capture the shortened peak but the software hasn't seemed to find the
peak. When does the software actually identify the reference peak? At
the beginning, middle, or end of the peak width? Is there a minimum peak
width before the software notes that a peak exists? How can I
re-evaluate my peaks to obtain values for my sample peaks?

Thank you, Anne
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Anne M. Cotter
U.S. Environmental Protection Agency
Mid-Continent Ecology Division
6201 Congdon Blvd
Duluth, MN 55804
218-529-5183
fax 218-529-5003
[log in to unmask]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~