Flowserve PMV P4 - Manual (Page 22)

22
O-rings
With time and use, O-rings can become brittle. This can cause poor operation and even
failure of the positioner.
Always check O-rings when performing any work on the positioner and replace bad O-
rings.
A thin layer of silicon grease applied on the NBR (Black) O-rings prolongs their life. On Q
(red) O-rings, use a non silicon based grease.
Filter plug (EP5)
Caution! Do not operate the unit without filter and filter plug installed. Do not attempt
to unscrew filter plug while positioner is pressurized.
EP5 is equipped with a built in secondary filter located on the side of the I/P unit.
For replacement or inspection, make sure that positioner unit is not pressurized, then unscrew
filter plug 1. Remove filter 3 and install a new into the filter plug . Check condition of O-
ring 2 and filter compartment. If moisture is found, check upstream filters/oil-water separators.
Moisture can cause I/P failure.
Reinstall filter plug.
1
2
3