Welch Vacuum 2028 Self-Cleaning Dry Vacuum System - Manual (Page 18)

Section 4: MAINTENANCE
4.10 General Maintenance
Welch dry vacuum units are 100% oil-free. The pump employs a diaphragm with uninterrupted PTFE
coating. No maintenance is necessary for the bearings. All bearings are sealed and permanently
lubricated. Lubrication should not be attempted.
Welch’s Recommendation:
To extend the service life of the diaphragm membrane, turn off the Self-Cleaning Dry Vacuum System
when not in use. Running the system when not being used only creates wear on the fl exing membrane in
the pump. When running the pump for several hours at a time in an application, Welch recommends air,
vapor or gas pass through the pump rather than run in a blank-off condition. The air, vapor or gas aid in
cooling of the pump mechanism extending the membrane’s service life.
Section 5: CALIBRATION
5.10 Starting the Calibration for Model 2027 only
Under normal conditions the digital vacuum gauge on model 2027 vacuum system should not need
recalibration as it has been factory set. To recalibrate the unit an external vacuum gauge capable of
measuring down to 2 Torr or less will be required.
Step 1: With unit powered off press and hold both the power and vent buttons until the
MENU screen is in the display.
Step 2: Use the vent button to select About (menu item 2).
Press the power button when About menu item is selected.
Step 3: The About screen will now be in the display.
Now press both the power and vent buttons together to go to the CALIBRATION/INFO screen.
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