(1) Lubrication. Use the correct and the proper amount of
oil; excessive lubrication rarely does as much harm as inadequate
lubrication. Only nondetergent oils may be used. Recommended
lubricating oils are listed below.
(a) SAE 10 non-detergent for ambients below 100
degrees F (37.9 degrees C) (fig. 3-1).
This is a dry air pump, and liquids must not be
allowed to enter the intake. In vacuum filtration,
a second side-arm flask should be used as a trap,
connected between the side arm of the filtrate
receiving flask and the pump vacuum air inlet (fig.
3-2). With aqueous liquids, a small amount of
silica gel in the trap flask will absorb any water
vapor and prevent rusting.
To ensure proper lubrication of the rotor and pump
vanes, before using the pump for the first time,
connect the pump to the proper electrical outlet
and run it free to the atmosphere (without load)
for about 5 minutes. This precaution should be
repeated whenever the pump is used for vacuum
filtering aqueous solutions, to prevent rusting
due to entrained water vapor.
(b) Military Symbol PE-10 (MIL-L-21260, Type I).
(c) Military Symbol 2110 (MIL-L-15016, Rev A).
(2) Starting. If motor fails to start or hums, pull the
plug and check for correct voltage as shown on the motor nameplate.
Also examine the plug and switch. Some motors are equipped with
overloads that turn the current off automatically when subjected
to mechanical or electrical overload. If the unit is extremely cold,
bring it to room temperature before starting.
(3) Flushing. Most pump trouble can be corrected by
flushing rather than taking the pump apart. A noisy or inefficient
pump is frequently nothing more serious than a vane or vanes stuck in
a rotor slot due to excessive oiling or heavy oil. Remove the inlet
and outlet accessories and add a tablespoon of kerosene slowly at the
intake while the unit is running. Lay unit on its side with outlet
downward so kerosene will work out again. Return the pump to the
upright position, place three to five drops of oil in the intake port
and reattach the accessories.