Brooks Instrument 5851E - Manual (Page 38)

4-6
Brooks ® Model 5851E
Section 4 Maintenance Installation and Operation Manual
X-TMF-5851E-MFC-eng
Part Number: 541B104AAG
November, 2008
When performing the following procedure the valve stem must be
removed without cocking it to prevent damage to the valve spring.
CAUTION
4. Carefully remove the valve stem assembly (6).
5. Remove the plunger assembly (7, 8, 9, 11).
6. Remove and note the position of the valve spring spacers (10), which
may be located above and/or below the lower valve spring (8).
7. Unscrew the orifice (12) from the flow controller body (14) using the
orifice removal tool (See Section 5, Table 5-2).
8. Remove the three screws (20) attaching the electronics cover. Remove
the electronics cover (23).
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.
CAUTION
9. Unplug the sensor connector from the PC Board. Remove the two
screws securing the bracket (24) and PC Board (15). Remove the
bracket and PC Board.
10.Remove the two allen nuts using an 1/8" allen wrench (18) and washers
(19) securing the sensor assembly (16). Remove the sensor assembly.
Note: Do not attempt to disassemble the sensor assembly.
Do not scratch the O-ring sealing surface.
CAUTION
11.Remove the sensor assembly O-rings (17) from the flow controller body
(14). Using the Brooks O-ring removal tool will help prevent scratching
the sealing surface.
12.Remove the adapter fittings (27) from the flow controller body (14).
13.Remove the 4 screws (31) from the end block (30) and carefully
remove the end block.
14.Remove the restrictor assembly (21) from the inlet side of the flow
controller body (14) using the header removal tool (Section 5, Table 5-
2). Note the rotational position of the restrictor assembly. (Refer to
Section 4-7).
B. ASSEMBLY
Do not get Halocarbon lubricant on the restrictor element (21) or
hands. Rubber gloves are recommended. This is a special inert
lubricant which is not easily removed.
CAUTION