Brooks Instrument QMBM User Manual
Page 48
Section 4 Maintenance
4-8
Installation and Operation Manual
X-CM-QmB-eng
Part Number: 541B029AAG
June, 2011
QmB Series IP40, IP66, IP66XP
Assembly
1.
Examine all parts for signs of ware or damage, replace as necessary.
Refer to the parts list Figure 4-3.
2.
Install the metal seal, item (2) in the center of the valve body, item (1).
3.
Install the orifice, item (3) in the valve body, item (1).
The lower protrusion on the orifice must center in the orifice
seat! The seal must be new and un-used.
4.
Install the valve seat, item (5) in the valve cavityon top of the orifice.
5.
Install O-ring, item (3) in the valve body, item (1). it is recommended
that a new O-ring be used. Refer to parts list in Figure 4-3. When
ordering the O-ring specify the correct compound i.e. Viton, Kalrez
etc. depending upon your specific process.
6.
Install the vavle stem, item(6) over the valve seat, item (5) and center
of the valve body, item (1).
7.
Install the four valve screws, item (7) until they make light contact
with the base of the valve stem, item (6). Torque the valve screws in
a diagonal pattern in three increments slowly rising to a final torque
value of 175 inch-pounds (20 N-m). Refer to Figure 4-4.
8.
Install the valve coil, item (8).
9.
Install the valve cover, item (9).
10. Install the vavle nut, item(10) hand tight (snug).
11. Pressure and leak test to local standards.
Note: Standard Brooks Instrument pressure test is 1.5 times the design
pressure marked on the valve and a helium leak test at 1 x10
-9
bar .cc/s
helium maximum.
Note: The above leak test only evaluates the outbound seals. The
inbound seal should be also evaluated. This can be accomplished while
the unit is on the bench or when returned to normal service.
Figure 4-2 Parts List
Item No.
Description
Part Number
Quantity
9
Valve Nut
573Z275CEF
1
8
Coil Cover Assembly
185Z314AAA
1
7
Socket Head Screw
751Z152AAA
4
6
Stem
949Z256QOT
1
5
Plunger Assembly
622Z252QOG
1
4
Orifice .014 dia.
577Z559BMG
1
3a
Stem O-ring, Kalrez
375B024TTA
3b
Stem O-ring, Viton
375B024QTA
3c
Stem O-ring, Buna
375B024SUA
3d
Stem O-ring, EPDM
375B024SOA
2
Orifice Seal
763Z075AAA
1
1
Valve Body
092Y320BMT
1
1