8
3.10 Starting
Procedures
3.11 Starting a Welch Dry Vacuum Pump
Before attaching the pump to a system it is well to familiarize yourself with the function and
action of the pressure vacuum pump that you have acquired. Review the power requirements
as described in Section 2.6. Welch recommends running the pump for a few minutes to warm
up before use. The warm-up improves the pump’s 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 will come off the process during
evacuation, a particle trap in the foreline 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.
3.13 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 pumps can
be located by slightly pressuring the system and painting the suspected area with a thick soap
solution. Escaping air will produce soap bubbles.
3.14 Operating Pressure Range
Model 2585 Dry Vacuum Pumps are designed to be run from atmospheric to their maximum
vacuum level on the intake side. Consult the Specifi cation Table in the back of this manual for
the ratings for your specifi c model.
3.15 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
Welch dry pressure / vacuum 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. The units are built for continuous duty operation with
the quietness and durability of a diaphragm, but with piston pump performance.
