Brooks Instrument GF81 - Manual (Page 28)

2-8
Brooks ® GF40/GF80/GF81 Devices
Installation and Operation Manual
X-TMF-GF40-GF80-Series-MFC-eng
Part Number: 541B161AAG
June, 2013
Section 2 Installation
2-13 Perform a Leak Test
It is critical to leak test the gas supply lines and GF40/GF80/GF81 Series
connections before turning on the process gas supply after any new
installation. Check for leaks using a helium leak detector or any other
appropriate leak test method. Follow leak test specifications as defined by
integrator.
2-14 Performance Checks
This section describes how to zero and sequence the GF40/GF80/GF81
Series devices for proper operation.
• The GF40/GF80/GF81 Series must be warmed up for at least 45 minutes.
• The active gas page must be correct.
2-15 Zeroing Setup Process
The following steps are required before the GF40/GF80/GF81 Series is zeroed.
1. Place the GF40/GF80/GF81 under normal inlet operating pressure.
2. Make sure that the GF40/GF80/GF81 Series has been installed inside
the equipment (panel) for at least four hours and powered up at least
one hour prior to zeroing. This insures that the GF40/GF80/GF81 Series
is in its "use attitude" and is operating at normal temperature. If the
GF40/GF80/GF81 Series is subjected to a vacuum purge for more than
one minute, turn off the GF40/GF80/GF81 Series (i.e., provide a zero
setpoint) for a time period of twice the vacuum purge time.
3. Refer to Figure 2-1. Open the upstream shut-off valve (5) and close the
downstream shut-off valve (7). This eliminates a pressure drop across
the GF40/GF80/GF81 Series and subsequent leakage from the PID
control valve inside the GF40/GF80/GF81 Series.
4. Provide a 100% setpoint to the GF40/GF80/GF81 Series for no longer
than 30 seconds. This equalizes the pressure across the PID control valve.
5. Refer to Figure 2-1. Close the upstream shut-off valve (5) to prevent any
pressure effects from the regulator (3).