Welch Vacuum 2511B-76, C-75, C-76, C-77Aspiration/Filtration - Manual (Page 9)

3.30 Operating Pressure Range
3.31 Aspiration/Filtration Vacuum Systems are designed to be run from slightly below atmospheric to their
maximum vacuum level on the intake side. The pumps also may be run from atmospheric to their
maximum rated pressure rating. Consult the Specifi cation Table for the ratings of your specifi c model
(See Section 6, Specifi cations).
3.40 Shutdown Procedures
3.41 After use, Welch recommends the pump be run for about 2 minutes disconnected from the vacuum
process. The air pumped through the mechanism will purge out water vapor or droplets of water
condensate that may have formed on the inside of the pump. This purge of the pump mechanism
helpsprevent corrosion, and maintain performance.
SECTION 4: MAINTENANCE
4.10 Maintenance Procedures
4.11 Maintaining a Welch Aspiration/Filtration Vacuum System
These units are 100% oil-free. The pump employs a non-lube piston and cylinder. No maintenance is
necessary for the bearings. All bearings are sealed and permanently lubricated. Lubrication should not be
attempted.
4.12 Empty collection vessel
Your 2511 aspiration station uses a fl oat valve on the collection vessel lid to prevent overfi lling and
provide pump protection. To empty, remove the middle collection vessel tube (“to pump”), set lid aside,
empty collection vessel appropriately, reinstall collection vessel and lid, and reconnect pump to lid.
4.13 Hydrophobic Filter Replacement
Change
the fi lter whenever foreign material is drawn into it or if you notice a reduction in vacuum level.
1. Disconnect the long tube from the fi tting on top of the jar lid.
2. Gently pull the hydrophobic fi lter off of the short tube, that is connected to the regulator inlet port, and
then remove the long tube from the hydrophobic fi lter .
3. With the green dot facing down, push the new hydrophobic fi lter into the short tube, that is connected
to the regulator inlet port, then push the long tube.
4. Connect the long tube to the green dot facing barb, and then connect to the fi tting on top of the jar lid.
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