we use them since many year after a crash of the Dual Inlet Duo 2.5 FV pump and and oil mess in my Dual inlet…however, we also replaced all Duo 2.5 by larger FV pumps (Duo 5M and RV3) and from my opinion that was even more important than the fore-line traps. But together with the Foreline traps oil mist in the vacuum tuning to the turbo pumps is gone.
We typically replace the filling by a new one once per year when we do the regular oil change (we tried to recycle it in a furnace - what a mess). The trick for a good and fast vacuum is to install the foreline trap “hot”. We typically heat them up at 400°C for 2h, let them cool down and then put them into place. We also do that it the pump was off for some time (e.g. the Dual Inlet that is not in use continuously).
I cannot observe a difference in vacuum readings with or without fore line trap installed, when installed hot. However, when a system was under atmosphere for some time and then pump switched on it is difficult to reach a good vacuum without prior heating of the filling. Am not aware of any alternatives.
> Am 19.07.2019 um 22:10 schrieb Julien Foriel <[log in to unmask]>:
> We're using FL20K foreline traps on rotary pumps connected to mass specs and vacuum lines (and I've used Ulvac OMC filters before), but I don't know how good these really are in terms of oil mist trapping and loss of vacuum, and if there are better alternatives.
> Julien Foriel
> Lab manager
> Johnston Lab
> Harvard U.
PD Dr. Robert van Geldern
Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) | GeoZentrum Nordbayern
Schlossgarten 5 | 91054 Erlangen | Germany
[log in to unmask] | www.gzn.uni-erlangen.de