Waters Xevo G2-XS QTof Overview And Maintenance Manual page 126

6 Maintenance Procedures
3. Use the 10-mm wrench to fit and tighten the nut that secures the oil
demister element to the exhaust flange.
4. Ensure that the inscription "TOP" is at the top of the oil demister
element, and, using both hands, carefully fit the oil demister element
and exhaust flange to the roughing pump.
5. Use the 6-mm Allen wrench to fit the 4 bolts securing the exhaust flange
to the roughing pump.
Requirement:
the roughing pump sequentially and by small increments until they are
all fully tight.
126 April 2, 2015, 715004496 Rev. B
Tighten the bolts securing the source exhaust flange to
1 mm exposed thread after tightening
TP02686