6.2.2 GFM 17 models
Unscrew the inlet compression fitting of meter. Note that the Restrictor Flow
Element (RFE) is connected to the inlet fitting.
Carefully disassemble the RFE from the inlet connection. The 50 micron filter
screen will now become visible. Push the screen out through the inlet fitting. Clean
or replace each of the removed parts as necessary. If alcohol is used for clean-
ing, allow time for drying.
Inspect the flow path inside the transducer for any visible signs of contaminant. If
necessary, flush the flow path through with alcohol. Thoroughly dry the flow paths
by flowing clean dry gas through.
Carefully re-install the RFE and inlet fitting, avoiding any twisting and deforming
the RFE. Be sure that no dust has collected on the O-ring seal.
NOTE: OVER TIGHTENING WILL DEFORM AND RENDER THE RFE DEFECTIVE.
IT IS ADVISABLE THAT AT LEAST ONE CALIBRATION POINT BE CHECKED
AFTER RE-INSTALLING THE INLET FITTING-SEE SECTION (7).
6.2.3 GFM 37/47 Models
Unscrew the four socket head cap screws (two 10-24 and two 6-32) at the inlet side
of the meter. This will release the short square block containing the inlet compression
fitting.
The 60 micron filter screen will now become visible. Remove the screen. DO NOT
remove the RFE inside the flow transducer! Clean or replace each of the removed
parts as necessary. If alcohol is used for cleaning, allow time for drying.
Inspect the flow path inside the transducer for any visible signs of contaminants.
If necessary, flush the flow path through with alcohol. Thoroughly dry the flow
paths by flowing clean dry gas through.
Re-install the inlet parts and filter screen. Be sure that no dust has collected on
the O-ring seal.
It is advisable that at least one calibration point be checked after re-installing the
inlet fitting - see section 7.
6.2.4 GFM 57/67/77 Models
It is not recommended to open high flow models. However, if customer decides
to clean RFE, below procedure is suggested.
Unscrew the four socket head cap screws (10-24) at the inlet side of the meter.
This will release the short square block containing the inlet compression fitting.
(3/4" NPT for GFM77)
10
