EBARA 80?25 Installation Operation & Maintenance page 42

EBARA Multi-Stage Dry Vacuum Pumps
Prior to removing the piping, it is helpful to mark which side it was removed from, i.e.,
exhaust piping and inter-cooler piping in between the pump and coolers, check, valve,
etc.
1. Remove all piping.
2. Seal off the openings in the bottom of the pump with duct tape to prevent moist
air from getting inside the pump.
3. Transfer all parts to be cleaned to a sink with a vented hood; have the sink filled
with water.
4. Check the end caps and bodies of coolers to determine if alignment markings
are stamped on them, i.e.; U1, U2, or U3. If they are not marked, mark or
scratch both bodies and end caps to ensure correct alignment during re-
assembly of coolers.
5. Remove the end caps by removing eight - 8 mm bolts using a 6 mm hex wrench.
CAUTION
!
If any of the bolts are seized, apply WD-40, Liquid Wrench, LPS, or other
penetrating product in liberal amounts while torquing the bolt back and forth.
This will usually loosen the bolt and prevent twisting off the bolt head.
6. Remove the O-ring and set it aside.
7. Write down the % amount of build-up in the coolers. (Photocopy and use the
Cooler Cleaning and Inspection Form).
8. Soak the coolers, or rinse them off if necessary, until all process build-up is
dissolved from the coolers.
NOTICE
!
If a helium leak detector is not available, proceed to #9. If a helium leak detector
is available, skip to #10 and continue through #15. After #15 perform a helium
leak check.
9. Check all coolers for leaks by blanking or plugging off one water connection.
Apply Nitrogen or compressed air at 5.3-7.0 kgf/cm2 (75-100 psi) to the other
water connection. Submerge cooler body under water and look for bubbles
escaping. Repeat the rest on all cooler bodies. If the cooler leaks, DO NOT
USE! Replace cooler.
10. Place all clean parts in an oven and bake at 190°C (375°F) for one half hour, or
at 150°C for one hour, to get out all of the moisture. A vacuum is desirable, if
equipment is available.
WARNING
!
Wait until all of the parts are cool and dry before starting to reassemble them.
930601-P
Pump Maintenance
34