Brooks Instrument FC8800 Series - Manual (Page 23)

3-1
Section 3 Operation Installation and Operation Manual
X-VA-FC-eng
Part Number: 541B045AAG
March, 2012
Flow Controllers for Gas and Liquid Service
3-1 Operating Precaution
3-2 General
Series FC 8800:
After the flow controller is installed and the downstream
condition established, adjust the upstream pressure to the value required
to pass the maximum flow rate desired with the integral valve 90% open. If
a flow meter is used it should be installed downstream of the controller
where the pressure is constant. Do not attempt to use the valve for shut-
off. If tight shut-off is required a separate on-off valve should be installed
upstream of the controller. Should the downstream condition change, thus
changing the pressure, a proportional change in flow rate will result.
Model FC 8744 & Series FC 8900:
After the flow controller is installed and
the upstream condition established, adjust the downstream pressure to the
value required to pass maximum flow rate desired with integral valve 90%
open. A good pressure regulator should be installed upstream of the
controller. If the supply or upstream pressure varies, the flow rate will vary
proportionally. If a flow meter is used for rate indication, install it on the
constant pressure or upstream side of the controller. Use a separate valve
for tight shut-off, if required.