Brooks Instrument 5850i - Manual (Page 35)

4-7
Brooks ® Model 5850i
Section 4 Maintenance Installation and Operation Manual
X-TMF-5850i-MFC-eng
Part Number: 541B108AAG
December, 2008
4-3 Sensor Tube
The sensor tube is part of a calibrated flow divider that is designed to
operate within a preset gas flow range. The sensor assembly may be
removed or replaced by referring to Section 4-4, Disassembly and
Assembly. If the sensor assembly is cleaned and reinstalled, a calibration
check should be performed. Refer to Section 3-4.
4-4 Disassembly and Assembly
The Model 5850i Mass Flow Controller may be disassembled in the field by
the user for cleaning, re-ranging or servicing. Disassemble and assemble
the controller as follows: (for normally open valves N.O.)
Figure 3-5 shows the location and function of jumpers. The jumpers J4 and
J1 (blue) must be in the position indicated for a normally open valve.
Figures (labeled 4-2a and 4-2b) shows the location and function of valve
adjustment spacers for normally closed and normally open valves.Valve
adjustment is not required for normal installation and operation of the mass
flow controller. If adjustment is required, consult the factory for information.
Figure (labeled 5-1) shows an exploded view of the controller and specific
parts to the (normally closed NC and normally open NO valve.)
Note: The Model 5850i Mass Flow Controller should be disassembled and
assembled in a clean environment to prevent particulate contamination.
A. Disassembly (Normally Closed)
The numbers in () refer to the spare parts exploded view in Figure 5-1.
1. Remove the jam nut (1) on top of the valve assembly.
2. Unplug the valve connector from the electronics cover and remove the
coil assembly (2).
3. Remove the hex socket screws (3) securing the valve retaining plate
(4) attaching the valve stem assembly (6)(NC valve - Normally Closed)
or (34) (NO Valve - Normally Open).
4. Carefully remove the valve stem assembly (6)(NC Valve) or
(34)(NO Valve).
5. Remove the plunger assembly (7,8,9,11)(NC Valve) or
(35,31,32,8,9,11)(NO Valve).