The sinter filter is designed
to protect the HPLC system from particles in the mobile phase.
Eventually it will block. The symptom of a blocked filter are
cavitation in the solvent lines (air bubbles forming when no
air is seen to enter the filter). This results from the suction
of the pump being unable to draw solvent through the filter fast
enough and hence the reduced pressure draws air out of the solution.
Some sinter filters fit by pushing
the stem inside the 1/8" solvent line. Other screw on using
a flangeless fitting. We recommend the latter type.