Page 367 - The Tribology Handbook

Ci rcu I at i o n systems C18

Double-line systems METERING ELEMENTS
Double-line elements can be used in conjunction with a
reversing valve and piston or gear pump to lubricate larger
numbers of points spread over longer distances geographic-
ally. These elements and their operation are similar to FILTER -
those previously described under grease systems.

Typical applications
Machine itools, textile plant, and special-purpose
machinery.
RESERVOIR
Figure 18.5

Simple low-pressure systems DELIVERY LINE
The simple form illustrated uses a gear pump feeding
the points from connections from a main feed line through
needle valves with or without sight glasses.

Typical applications
Special-purpose machinery and machine tools.
COMBINED SIGHT FLOW
INDICATOR AND NEEDLE
RESERVOIR
VALVE
Figure 18.6

Gravity-feed systems
Gravity-feed systems consist of a header tank, piped
through to one or more lubrication points. The level in the
header tank is maintained by a gear or other pump with
relief valve and filter mounted at the collection tank.

Figure 18.7
YER
This may be used as a back-up for a forced-feed system TANK
where important bearings have a long run-down period RELIEF’ tALVE f3LTEY
~n, COYLER
after removal of the power source, e.g. large air fans. . :TURN
PUM

RETURN

SUCTION DRAIN
MAIN TANK
Figure 18.8

C18.3