2014 SMRP Slide Presentation--Orlando FL.pdf

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About This Presentation

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Slide Content

2014 SMRP Closing Keynote

Reliability Enhancements with 10:1 Payback

You’ve heard it here, at this conference. And you understand
it. So now please do it!


Heinz P. Bloch, P.E.
Process Machinery Consulting
Westminster, Colorado 80031-6837
[email protected]

The most important thing you’ve learned
is that you can make a huge difference
•You can use either an open
jaw wrench or a box wrench
•You will decide whether to
use a sledge hammer or a
plastic hammer
•You can measure and record
the width of a slinger ring.
Or you can say “why should
I care?”

You can mount a constant level lubricator on
the correct side or on the
wrong side:
Enhancement No. 1

And you should only use balanced
lubricator models

•Unbalanced version

Cost comparison and payback: Incremental
cost $27, ratio >10:1
•$61 balanced vs. $34 for unbalanced lubricator
•Assume $150 for total conversion cost
•Replace on attrition basis and visualize fewer
pump repairs/year, say, 140 vs. previous year
160 out of a 1,000 pump population
•Avoided 20 repairs at $6,000 each = $120,000
•Cost outlay ($150)(160) = $24,000

Number 2: You can eliminate over-pressuring
shielded, grease-lubricated
bearings
Others have done this on their
electric motors 30 years ago
Still, some leave a drain plug in
place and then have frequent
bearing distress
Many pros specify what bearing
lube method is needed in
their plant. After all, they
specify voltage, speed,
horsepower---so why not
lubrication details? Your job?

And you learned that these two dual seals differ;
surely the seal on the left does not get cooled. So, why do
you still allow it? Please don’t single-source stuff.

That’s Number 3

Upgrade to mechanical seals with internal flow
baffle (a “barrier flow guide”)

Bi-directional barrier fluid pumping device
(“tapered barrier fluid impeller”)


• More efficient
• No cost impact
• Moves more
cooling fluid to the
critical region
of a mechanical seal

Barrier fluid flow rates often vary. The point:
Benefit from making more than one vendor your tech resource

•Typical
comparative
barrier fluid
flow rates
for dual
mechanical
seals

Details explain failures. All failures
have causes---risk avoidance Number 4
•Ask what happens to oil
getting trapped behind
the bearing?
•What happens if a slinger
ring gets caught between
shaft and screw?
•What happens if the shaft
is not perfectly horizontal
or if the slinger rings are
not stress-relieved (not
annealed)?

Consider a simplified mathematical expression for Life
Cycle Cost, LCC
LCC = C
ic
+ C
in
+ C
e
+ C
o
+ C
m
+ C
dt
+ C
env
+ C
d
+ C
f
- C
v

___________________________________________________
C
ic
= Initial cost, purchase price
C
in
= Procurement and installation, incremental cost
C
e
= Energy costs (pump, driver & auxiliary services)
C
o
= Operation costs
C
m
= Maintenance and/or repair costs
C
dt
= Downtime costs
C
env
= Environmental costs
C
d
= Decommissioning and/or disposal costs
C
f
= Fire damage cost
C
v
= Gain due to pro-active use of re-assigned workforce

Enhancement opportunity/case history Number 5:
synthetic lubes for rolling element Bearings
High film strength synthetic lubricants are used

(1) Four-to-six fold extension of lube life typical
(2) Ideal for severe applications: 18 hot oil pumps
--Yearly PM labor reduced from 200 hrs to now
only 50 hrs. (150 hrs) x ($50/hr)=$7,500/yr

150 man-hours now freed up for proactive tasks
elsewhere in the refinery

Disposal costs reduced

Synthetic lube for an Ultraformer® pump
•Disappearance of high vibration and noise explained
•Bearing change only: $ 2,500
•Bearings and seals: $ 13,000
•Complete overhaul: $ 54,000
•Unit downtime avoidance: $140,000/day

Benefit-to-cost ratio on frequently failing (“bad
actor”) pumps virtually always exceeds 10:1

Failure experience on 30 pumps in hot water service
points to the value of using high-grade synthetics (No. 5)
•Two or three bearing failures ever six weeks over a
period of several years!
•Candidate for rigorous root cause failure analysis and
systematic upgrade efforts that are subject of
presentation
•Pumps on “bad actor” list typically 10% of installed
pumps in refineries, but consuming 60% of
maintenance expenditures for all pumps
•Upgrade efforts encompass entire pumping system,
incl. piping and pump support method

Perhaps we have learned when to use diester-based synthetic
lubricants for reciprocating compressor cylinder lubrication:
Our enhancement opportunity Number 6 Compressor discharge valve Compressor discharge valve
after 6 months’ service with a after 6 months’ service with a
diesterdiester
Compressor discharge valveCompressor discharge valve
after 4 months’ service with after 4 months’ service with
petroleum base lubricantpetroleum base lubricant
SYNTHETIC CYLINDER LUBRICATION
Ref: ExxonMobil

Perhaps you’ve learned that Number 6 cannot be done
without Number 7 and the problem starts with not
budgeting/teaching/pursuing MQA

Payback for use of diester cylinder lubes
•An incremental outlay of $320 returned savings of
$10,130 --- for a 30:1 payback with Opportunity No. 7

Cost impact of mineral oil versus diester synthetic in
compressor cylinders

Mineral Oil Diester Synthetic
Yearly consumption and 80 gal@ $3 40 gal @ $14
cost of cylinder lubricant = $ 240 = $ 560

Yearly cost of main- 200 m-h @ 80 m-h @
tenance labor $50 = $10,000 $50 = $ 4,000

Yearly cost of valves or
cost of valve repairs $ 4,300 $ 2,150

Prorated/imputed delta-
cost of cyl.rebuilds/year $ 2,300 ------

Total Cost: $16,840 $6,710

Pre-grouted base plates: Lower installed cost
than conventional base plates--Enhancement
opportunity Number 8

Conventional grouts cure from inside – base plate
distortion must be remedied with “skim cut”

Pre-filled base plate, foundation and form details--only
needs caulk/wax/chipping

Economics of pre-filled base plates for pumps and other
machines open up Enhancement Opportunity Number 8
•Base plate rigidity is often unsatisfactory
•Even cast iron baseplate often sold in warped condition
•Pre-filling with epoxy must be preceded by careful
application of a suitable primer
•Curing, inverting, skim cut taken over the various
mounting surfaces
•Installation on chocks, leveling not difficult at this time
•Grouting after placement of suitable forms

Recap Enhancement Number 8: Less expensive, and yet
much more long-lasting

•Typical as-installed baseplate cost comparison:
Conventional vs. Pre-Filled
$ 6,259
$ 4,194
$ 2,065 saved

IMMEDIATE
PAYBACK!

Number 9: Bearing housing seals: Why needed
and how cost-justified? What’s the payback?
•Lube oil contamination is a major source of bearing
distress
•Only 9% of total bearing population reach L10 life
(L10 means operating time at which 90 percent of the
bearings are still working well)
•Bearing housing seal progression:
>>Lip seals>>labyrinth seals>>single-faced magnetic
seals>>double-faced magnetic seals>>rotating
labyrinth seals, often called “bearing isolators”

Where does it go on a typical centrifugal pump?

The sales leader in bearing housing seals,
rotating labyrinth style (~1996)
Areas of concern:
(1) A moving O-ring in
proximity to a sharp-
edged O-ring groove.
(2) A rotor fastened to the
shaft with only a single
clamping O-ring

Leading in technology: Axially moving
O-ring bearing housing seal, (~2006)
•Upper left--concerns
•Upper right--friction
•Lower one incorporates
two clamping rings.
Dynamic O-ring moves
in radial direction,
allowing large O-ring to
move axially. No risk of
contacting sharp edges

We are still on enhancement opportunity No. 9:
Advanced bearing housing protector seals

Dual-face magnetic
bearing housing seal
(introduced ~2003) •Used for “hermetic”
sealing
•Slight modification
makes it best for closed
oil mist systems
•Costs more initially

What good bearing housing seals will do
•Depending on style, will reduce or prevent
“breathing”--intrusion of airborne dust and water
vapor, thereby extending bearing life
•If “hermetically” sealing, will allow deletion of
constant level lubricators
•Extend lube replacement intervals
•Make it economic to use the more expensive
synthetic lubricants
•Facilitate the design of “closed” oil mist systems,
thus reduce stressing environment

Cost justification basis: Dual-face magnetic
housing seals every 5 years, versus lip seal
replacement every 12 months: 19-to-1

•One-time expenditure of $570 saves
$11,054 over a five-year period
•Calculation assumes no bearing
replacements or pump overhauls
•Study does not take into account shaft
repairs necessitated by lip seals that often
cause shaft surfaces to wear

Enhancement Number 10: Advanced pump wear ring
materials are great, but may (occasionally) have to take into
account that rotor axial thrust will change
The function of wear rings
Wear rings separate rotating and stationary, higher and lower-pressure sections of a pump. A
major component of pump efficiency is the recirculation flow across the wear rings. Reducing
wear ring clearance reduces the area between the wear rings; therefore, reducing the
recirculation flow and increasing pump efficiency.
Wear rings
RRings
Rings Throat bushing
bbbbbbushing
bBushing
• Wear Rings
• Throat Bushings
• Throttle
Bushings

1. Vespel
2. Teflon
3. PEEK
4. Others

The right HP polymeric wear material
has many advantages
•Extended dry-running capability
•Allows clearance reduction of up to 50%
•Energy savings ~ 4%
•Lowering of NPSHr
•If resulting pump MTBR is 7 years and
conventional MTBR is 5 years, payback
exceeds 27:1
•Thermal expansion of “A” is 8-times “B”

Wear rings, cast iron versus Vespel®


Cost, 2 Items C.I.: $ 520/5yrs V: $1,000/7yrs
= $ 104/yr = $ 143/yr
Efficiency Gain Base 4% of 75 kW=3kW
Yearly Value, (26,280
kWh) x($0.06/kWh) $ 1,576 Base
Repair Cost, per year,
Basis $8,000/5yrs Basis $8,000/7yrs
= $ 1,600/yr = $ 1,143/yr

Total, per year $ 3,280 $ 1,286
Savings, per year Base $ 1,994

Avoiding oil rings is Enhancement No. 11 ---
know the many shortcomings of oil rings!
DN=Shaft diameter
(inches) times RPM

Guideline value is
6,000---it’s based
on field experience
and risk-averse
reliability principles

Typically desired oil ring (“slinger ring”)
dimensions
•Sensitive to shaft
horizontality
•Depth of immersion
•Oil viscosity
•Surface roughness
•Ring concentricity
•Shaft rpm

Why oil rings (“slinger rings”) may not be
your best application choice
•Note difference between a brand-
new ring and the worn ring on the
right. It caused oil contamination
•The most important questions for
SMRP members: Are you
measuring before-versus-after
dimensions?
•Are they logged in your CMMS
data base?
•Why are many oil rings not
concentric to begin with?
•What are you doing about it?

Upgrading to flinger discs: A payback
example yields 20:1
•Assume a facility with 600 pumps.
Of these, 5% suffer from oil ring
deficiencies that put these (18)
pumps at risk
•They are being repaired every 3
years, at $6,000/incident; cost =
$36,000/year
•Assume that upgrading these 18
pumps to flinger discs increases
MTBR to 6 years, thus only one-
half the repair cost; $18,000 per yr
•Assume you bought 18 flinger discs
at $50 ea
•Payback: $18,000/$900 = 20:1

Or, No. 12, we could
be upgrading to
inductive pump lube
•Technology progression:
oil rings > flinger discs >
jet spray application
•Inductive pumps have a
single moving part, are
adjustable for speed and
flow; system arranged to
spray lube into space
between bearing inner
ring and cage
•Application simulates
circulating (“pressurized”)
oil systems with filters

Economics of inductive pumps for lubrication
•They fit many OEM and retrofit situations,
primarily in mid-size pumps and blowers
•Full systems cost in $2,000-$4,000 range
•Typical payback above 10:1 level, with
narrative example indicating 61:1 ratio
•Observe the principle of spraying oil into a
bearing. There are many ways to do that

Number 13: Cooling water is never needed for
rolling element bearing housings
•Jacket cooling tends to shrink outer ring
•Cooling water coils also cool air floating
above oil level---vapors condense
•Relatively little heat migrates along shaft, but
bearing friction heats oil
•Experience shows that increasing the viscosity
of lubricant makes up for additional heat input:
Cooling needed

You’ve learned that bearing housing cooling is not
needed (and can be detrimental) to rolling element bearings

So, save on repairs
and save on water •Consider synthetic lubes: ISO
Grade 32 synthetic oil = ISO
Grade 68 mineral oil
•2% efficiency advantage is an
added bonus
•Reduced oil contamination
increases life of bearings
•Savings due to reduced treated
water consumption and outfall
treatment costs
•Stress on environment reduced;
could save money and concerns
over regulatory compliance

You’ve heard a few words on ethics
•The expectations we have of a medical
professional and why they should carry over
•We are Professionals: SMRP
•We owe our boss facts. If we give advice
based on opinions, there could be problems
–Monetary consequences
–Safety consequences
–“Dumbing down” consequences

Reading
material
is available. It’s
cheap. Its benefit-
to-cost ratio often
exceeds 1000:1

Do we have time for questions?
•Synthetic lubes
•Compressor valves
•Mechanical seal issues
•Pre-filled base plates
•Bearing housing seals
•Polymeric wear parts
•Oil rings or finger discs
•Constant level lubricators
•Deleting cooling water

Upgrading ANSI/ISO Pump Bearings
•Double-row thrust bearings typically have only one
inner ring. With thrust load, unloaded side prone to
skid
•Skidding creates metal-to-metal contact and generates
heat
•Double-row thrust bearings with two inner rings
allow preloading, hence reduce skidding risk

Upgrading To Flinger Discs: A Payback
Example Yields 20:1
•Assume a facility with 600 pumps. Of these, 5%
suffer from oil ring deficiencies that put these
(18) pumps at risk
•They are being repaired every 3 years, at
$6,000/incident; cost = $36,000/year
•Assume that upgrading these 18 pumps to flinger
discs increases MTBR to 6 years, thus only one-
half the repair cost; $18,000 per yr.
•Assume you bought 18 flinger discs at $50 ea
•Payback: $18,000/$900 = 20:1

Upgrading ANSI/ISO Pump Bearings
•Double-row thrust bearings typically have
only one inner ring. With thrust load,
unloaded side prone to skid
•Skidding creates metal-to-metal contact
and generates heat
•Double-row thrust bearings with two inner
rings allow preloading, hence reduce
skidding risk

Double-Row Angular Thrust Contact
Bearing With Two Inner Rings

Where And When To Consider
DRACBB’s With Separable Rings
•Confirm that axial load exceeds capacity of
standard DRACBB, or:
•Confirm that there is skidding of the inactive row
of rolling elements. Then:
•Upgrade to split inner ring double-row angular
contact ball bearings
•For $200 in incremental labor and materials, and
assuming that a 1.5-year MTBR pump reaches a
3-year MTBR, you will probably avoid a $6,000
repair

Lubricant
Contamination:


A Major Source of
Bearing Failure

Dirt & Dust
Water & Scale
Corrosive
Products

Intelligent transfer
containers

• Protect Lubricants from
Contamination
• Reduce Machinery Downtime
• Minimize Spills & Accidents
• 10 Colors to Code Different
Grades of Lubricants
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