Machinery Lubrication May June 2014 May June 2014 | Page 8

specific reliability objectives. In the
context of this article, the ORS
defines the need for equipment
modifications and accessories that
optimize the state of lubrication.

stages that follow to the end of the
machine’s life. These stages are
described
at
http://www.
machinerylubrication.com/
Read/2471/reliability-engineersholistic-physicians-of-machine-care.
Again, this article addresses only the
first design stage.

While this is the critical beginning of the
reliability life cycle, there are many
MAINTAINABILITY
MACHINE DESIGN
FEATURES

CORRECT
LUBRICANT

STABILIZED
LUBRICANT HEALTH

Designing for Maintainability
Maintainability is typically defined as
the ease, economy, safety and accuracy
with which the necessary maintenance
of a machine can be effectively
undertaken.

When

machines

are

designed and built for optimized

CONTAMINATION
CONTROL

ADEQUATE AND
SUSTAINED
LUBRICANT SUPPLY

General Lubrication System Maintainability
Optimum selection/use of
a lubrication device (spray,
mist, circulation, grease,
bath, etc.)

N/A

May help stabilize lubricant
health

May help reduce the ingress and
removal of contaminants

Enables consistent and
sufficient supply of healthy and
clean lubricant

Lubricant type
identification labels

Type on machine
matches type on
lubricant package

Lower risk of mixed,
incompatible lubricants

N/A

N/A

Fully swept (purged) drain
sump bottoms

N/A

Water, sediment and other lowReduced residual, degraded
lying contaminants are swept out
oil (previous oil) from last oil
N/A
during drains (minimal fishbowl
change
effect)

Return-line diffusers and
tank baffles

N/A

Reduced aeration prolongs
oil life

Reduced oil aeration and
foaming, enables more efficient
and rapid contaminant settling

Heat exchangers/coolers

Ensures adequate
viscosity to enable
required film
strength in frictional
zones

Keeps oil at a stable
temperature for optimum
service life and reduces
premature additive depletion
(dropout, oxidation, etc.)

Reduces the risks of heat
contamination effects on additive Ensures proper fluid flow at
depletion and base
cold ambient temperatures
oil oxidation

Use of engine prelube
systems

N/A

N/A

N/A

Reduces engine dry-starts
causing momentary starvation

Pressure, flow and
temperature sensors

N/A

May indicate lubricantdamaging conditions

May indicate heat
contamination

May signal oil flow alarm
causing starvation

Fewer oil starvation issues
related to aeration and foam

Inspection Hardware Maintainability
Bottom sediment and water
(BS&W) sight glass

Oil color

Oil color, clarity, sediment,
sludge

Sediment, water emulsions,
free water, glycol (antifreeze),
biomass, varnish

N/A

Bull’s-eye 3-D oil
level gauges

Oil color

Oil color, clarity, varnish

Water emulsions, oil color,
aeration, foam

Oil level, aeration, foam

Correct oil level markings

N/A

N/A

N/A

Visual confirmation of correct
oil level

N/A

Visual inspection for bathtub
rings, floating debris,
foam, aeration, emulsions,
corrosion, varnish

Visual inspection for bathtub
rings, floating debris, foam,
aeration, emulsions, corrosion,
varnish

Helps detect foam/aerationinduced oil starvation risks

Pressure differential gauges
on filters (including engine N/A
oil filters)

Gauges help ensure filters
are working properly,
potentially prolonging
lubricant service life

Gauges help ensure filters are
working properly to control the
concentration of contaminants

Well-filtered lubricants are
less likely to cause excessive
wear on seals, which can
cause leakage and starvation
issues

Expanded-metal guards
and view windows for easy
inspection

N/A

Visible inspection of potential
contaminant ingression sites

Visible inspection of leakage
areas and lubricant-delivery
methods

Easy-open inspection
hatches/ports

N/A

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