Brooks Instrument 5861E - Manual (Page 25)

4-5
Model 5861E
Section 4 Maintenance Installation and Operation Manual
X-TMF-5861E-MFM-eng
Part Number: 541B107AAG
November, 2008
4-4 Disassembly and Assembly
The Model 5861E Mass Flowmeter may be disassembled in the field by
user for cleaning, re-ranging or servicing. Disassemble and assemble the
meter as fllows:
Note: the model 5861E Mass Flowmeter should be disassembled and
assembled in a clean enviromentto prevent particulate contamination.
A. Disassembly
The numbers in () refer to the spare parts exploded view in Figure 5-1.
Do not attempt to disassemble the mass flowmeter until pressure
has been removed and purging has been performed. Hazardous
gas may be trapped in the valve assembly which could result in
explosion, fire, or serious injury.
1. Remove the three screws (27) attaching the electronics cover and
loosen the upper jack post on the D-Connector. Remove the electronics
cover (40).
Be careful not to stress the sensor lead wire to sensor assembly
junction when removing the sensor connector from the PC board.
If the sensor lead wires are stressed an open in the sensor wiring
could result.
2. Unplug the sensor connector from the PC Board. Remove the two
screws securing the bracket (26) and PC Board (28). Remove the
bracket and PC Board.
3. Remove the two allen nuts (9) using an 1/8" allen wrench and washers
(10) securing the sensor assembly (7). Remove the sensor assembly.
Note: Do not attempt to disassemble the sensor assembly.
Do not scratch the O-ring sealing surface.
4. Remove the sensor assembly O-rings (8) from the flowmeter body (1).
Using the Brooks O-ring removal tool will help prevent scratching the
sealing surface.
5. Remove the inlet and outlet fittings(11) from the flowmeter body (1).
Remove the O-rings (19) from fittings.
6. Remove the 4 screws (5) from the endblock(3) and carefully remove the
end block.
7. Remove the restrictor assembly (37) from the inlet side of the body(1)
using the header removal tool(part of service kit tool kit listed in section
5, Table 5-2).Note the rotational position of the restrictor assembly. (
Refer to Section 4-6).