Machinery Lubrication May June 2014 May June 2014 | Page 16

of flushing oil is not needed. The
flushing process continues until the
predetermined

purity

criteria

are

reached in each location of the system.
During this time, the oil temperature
and direction of its flow are changed in
order to move out remaining impurities.
Effective flushing of the oil system is
based on the following three factors:
The process of drying an oil system (left) and application of a turbine oil spray as
anti-corrosive protection

special filtration and pumping units

1. Flow rates at all pipeline sections
should

be

sufficient

to

invoke

turbulence.

Immediate drying of the cleaned

with turbulent flows at rates ranging

2.

surfaces using filtered, compressed air

from 13,000 to 20,000 liters per

in various locations of the system

and applying a protective layer of

minute. These units have appropriate

should be better than required by

turbine oil (spray) prevent against

operating

the

secondary corrosion of the cleaned oil

connected to the oil system with hoses,

system. The system remains completely

manifolds, bearings, servo-motors and

dry after the hydrodynamic cleaning

other

phase, thus eliminating the risk of water

elements.

parameters

and

are

The oil cleanliness class measured

flow-restricting

ingression into the oil during flushing.
Flushing

is

Step 2: Flushing with Filtered Oil at
High Flow Rates

performed using

During this step, all impurities that

oil, which will

remain in the system after hydroblasting

remain in the

are

system

removed

while

ensuring

the

fresh

turbine

for

appropriate purity of the oil in the

further use. A

system. The system is flushed using

separate batch

Turbulent flushing with full-flow absolute filtration

turbine manufacturer (e.g., 17/15/13
according to ISO 4406). The oil’s purity
is measured during the flushing process
using appropriate instruments and
according to a predetermined schedule.
Cleanliness requirements can also be
set higher upon request.
3.

No solid particles greater than 150

microns

are

deposited

on

the

100-micron mesh strainers installed in
strategic locations throughout the
system. Smaller particle sizes may also
be warranted.
Depending
Hydroblasting of an oil system

14| May-June 2014 | www.machinerylubricationindia.com

on

the

customer’s

requirements, the oil purity criteria can