Welch Vacuum 2561B-50 WOB-L Pinston Pump - Manual (Page 9)

Section 3: OPERATION
3.10 STARTING PROCEDURES
3.11 Starting A Welch Pressure/Vacuum Pump
Before attaching the pump to a system, familiarize yourself with the function and action of the
pressure/vacuum pump that you have acquired. Review the power requirements as described
in Section 2.60. Welch recommends running the pump for a few minutes to warm it up, before
use. The warm-up improves the pumps ability to handle humid air.
3.12 Cleanliness
Take every precaution to prevent foreign particulates from entering the pump. Particulates
will damage the pump’s performance. If you fi nd that particulates come off the process during
evacuation, a particulate trap in the fore line will work. A simple, inexpensive trap may be
made by placing glass wool in a glass or plastic tube. Screens must be inserted to hold the
glass wool in place.
WARNING
The pump is not recommended for pumping acid, base or organic vapors
or gases. Serious damage to the pump will shorten the pump’s service
life. In addition, pumping fl ammable vapors or gases can lead to serious
safety hazard leading to fi re or explosion.
3.20 LEAK DETECTION
The importance of eliminating all leaks in a vacuum system is obvious. The pump must remove
this added volume of leaked gas to maintain the desired vacuum. Leaks for these pump can
be located by slightly pressuring the system and painting the suspected area with a thick soap
solution. Escaping air will produce soap bubbles.
3.30 PRESSURE RANGE
Vacuum pumps 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 (See Section 6, Specifi cations)
for the ratings of your specifi c model.
3.40 SHUTDOWN PROCEDURES
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 helps prevent corrosion.
Section 4: MAINTENANCE
4.10 GENERAL MAINTENANCE
Welch dry vacuum pumps 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. The units are built for continuous
duty operation with the quietness and durability of a diaphragm, but with piston performance.
9