Machinery Lubrication India Jan Feb 14 10 | Page 34

ISO CODE
(B)

DIRT (LBS.)
(C)

50-LB. BAGS

25 micron nominal

21/18

6,784

136

1

10 micron nominal

19/16

1,809

36

1.9

10 micron absolute

16/13

211

4.2

4.4

6 micron absolute

14/11

53

1

8.8

3 micron absolute

12/9

14

0.28

15

FILTER (A)

RELATIVE PUMP
LIFE

At ISO 21/18, this hydraulic system passes 136 50-pound bags of dirt through the teeth
of the pump in one year. At ISO 14/11, only one 50-pound bag of dirt passes through the
pump.

there is a problem with the lubricant in
your machines.

Verifying Lubricant
Cleanliness
Several studies indicate that the cost of
excluding a gram of dirt is only about
10 percent of what it will cost once it
gets into your lubricants. In some cases,
when new oils from major manufacturers
were tested, the ISO cleanliness codes
have ranged from 14/11 (pretty good)
to 23/20 (not good at all). The average
of these samples was 19/16, and several
were 20/18 or 21/18.
For those who may not understand ISO
cleanliness codes, they refer to values
on a Renard series table in conjunction
with particle counts of a specific micron
size. For instance, in a two-digit ISO
cleanliness code, particles of 4 and 6
microns are counted. A corresponding
value is then assigned based on the
number of particles of a specified size
and where they fall on the table.
Pounds of Dirt Passing
Through Pump/Year (C)

As you can see from the illustration
below, there is a significant difference in
particle counts between a code of
14/11 and 23/20. Keep in mind that
these numbers are for packaged
lubricants. For bulk deliveries, B