Maintenance Technology May 2017 - 36

LUBRICATION STRATEGIES

ISO 4406:1999 Solid Contamination Code Suitability Matrix
ISO RANGE

DESCRIPTION

22/20/17

Very Dirty

■ Unsuitable for any
system (H, L, G)
■ Medium/low-pressure
systems (H, L)

19/17/14

New Oil

17/15/12

Light
Contamination

16/14/11

APPLICATION

■ Non-critical gear
systems (G)
■ Standard hydraulic and
lube oil systems (H, L)
■ Standard gear systems (G)
■ Servos and high-pressure
hydraulics (H)

Clean

■ Critical gear systems (G)
<14/12/10

Very Clean

■ All oil systems (H, L, G)

LIFE EXTENSION

DIRT
p.a.*

0.5X (H)
0.75X (G)

600 kg

140 kg

1.6X (H)
1.3X (G)

34 kg

3X (H)
1.7X (G)

17 kg

4(H) - 2X (G)

8.5 kg

H = Hydraulic Oil, L = Lube Oil, G = Gear Oil
* Dirt through pump at 200 ltr/min., 230 work day, single shift in 1
Oil cleanliness is universally measured using the ISO 4406 cleanliness code rating system. (Source: EngTech Industries Inc.)

size present in the oil sample.
When new or virgin stock oil is
received from the supplier, many sites
believe they are receiving a "ready-touse" product. This is not always the
case, as depicted in the table. New oil
is typically received around a 19/17/14
ISO cleanliness level that may only be
suitable for non-critical gear systems.
All other applications will require the oil
to be cleaned and polished by passing it
through a filtration system prior to use
in service.
The table also notes that "In service"
oil dirtier than 19/17/14 is unsuitable
for any lubrication or hydraulic system.
Such oil will require replacement or
cleanup using a kidney loop set-up with
a portable filter cart.
The number of passes through the
filter cart to achieve the appropriate
cleanliness level will depend on the
"start" and "finish" cleanliness level and
the filter types and rating in use. Oil

36 |

MAINTENANCE TECHNOLOGY

analysis will be required to establish
cleanliness levels. Choosing a suitable
combination of pump and filter size/
type will require consultation with the
filter-cart manufacturer who will need
to understand your working environment and type/viscosity of oil(s) you
use.
The rate of cleanup (speed) will
depend on the reservoir size, pump flow
rate, and the cleanliness-rating delta.
What can be measured immediately is
the time to perform one complete filter
pass through the cart, as calculated
using the following formula:
(Reservoir size x 7)/filter-cart flow rate
= time for a single-pass filtration
Example: 60 gal. x 7/10 gpm =
42 min. for a single-pass filtration
(1 x filtration of reservoir capacity)
If the plant's lubricants are consolidated and cleanliness levels are known,

a matrix can be developed to determine
how many passes are required to filter
to an acceptable cleanliness level.

Best practices
As in all other facets of maintenance,
there are a number of best practices
associated with the use of portable filter
carts:
S Work with the filter cart supplier to
determine the right pump and filter
choice for your plant requirements.
S To eliminate cross contamination of
lubricants, each filter cart must be
dedicated to a single lubricant use for
transfer and cleaning of lubricants.
Pilot the filter cart program with the
most-critical and/or most-utilized
plant-lubricant type.
S Always clean the unit after each
successful transfer operation, paying
particular attention to the wand ends
and open drip tray under the filters
and pump area. Open oil is a dirt
MAY 2017

Table of Contents for the Digital Edition of Maintenance Technology May 2017