SYSTEM ONE - PowerPoint PPT Presentation

Loading...

PPT – SYSTEM ONE PowerPoint presentation | free to download - id: 777a0d-MjQ1M



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

SYSTEM ONE

Description:

IMPROVING PUMP RELIABILITY R. Antkowiak Maintenance vs. Capital What does a pump actually cost ? Most plants regard the pump as a commodity... purchased from the ... – PowerPoint PPT presentation

Number of Views:30
Avg rating:3.0/5.0
Slides: 71
Provided by: Richar1105
Learn more at: http://www.blackmercompressor.com
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: SYSTEM ONE


1
SYSTEM ONE
IMPROVING PUMP RELIABILITY

R. Antkowiak
2
(No Transcript)
3
Maintenance vs. Capital
  • What does a pump actually cost ?
  • Most plants regard the pump as a
    commodity... purchased from the lowest bidder
    with little consideration for
  • The operation and maintenance cost of the pump
    over its life cycle... which could be 20 - 30
    years
  • Costs to be considered
  • Spare parts (inventory costs)
  • Operation downtime (lost production)
  • Labor to repair (maintenance costs)
  • Power consumption based on pump efficiency
  • Environmental, disposal, and recycle costs


4
TRUE PUMP COSTS
  • Repair costs can easily exceed the price of a
    new pump (several times) over its life of 20 -30
    years
  • Documented Pump failures cost 4000 or more per
    incident ( parts and labor)
  • If MTBF was improved from 1 to 2 years for a pump
    in a tough application
  • Results in savings of 2000 /year over the life
    of the pump

5
WHY PUMPS AND SEALS FAIL
MECHANICAL
Affects Bearings, Seals and Shafts -EXTERNAL
1. Operation off the BEP 2. Coupling
Misalignment 3. Insufficient NPSH 4. Poor
Suction and Discharge Piping Design 5.
Pipe Strain / Thermal Expansion 6 Impeller
Clearance 7. Foundation and Baseplate -INTERNA
L 1. Pump Design and Manufacturing
Tolerances 2. Impeller Balance (Mechanical and
Hydraulic) 3. Mechanical Seal
Design
ENVIRONMENTAL Affects Wet End Components, Bearings
and seals 1. High Temperature 2. Poor
Lubrication / Oil Contamination 3.
Corrosion 4. Erosion 5. Abrasion
6
HOW ARE FAILURES INITIATED?
  • Installation
  • Piping system Pipe Strain
  • Alignment
  • Mechanical Seal installation
  • Foundation
  • Operational
  • System cavitation, dry running, shutoff
  • Product changes viscosity, S.G., temp.
  • Seal controls flush, cooling
  • Misapplication
  • Pump, seal, metallurgy selection

7
RADIAL LOADOperation of a pump away from the
BEP results in higher radial loads ...creating
vibration and shaft deflection
8
Radial Forces
  • By design, uniform pressures exist around the
    volute at the design capacity (BEP)
  • Resulting in low radial thrusts and minimal
    deflection.
  • Operation at capacities higher or lower than the
    BEP
  • Pressure distribution is not uniform resulting in
    radial thrust on the impeller
  • Magnitude and direction of radial thrust changes
    with capacity (and pump specific gravity)

9
Shaft Deflection
  • Most pumps do not operate at BEP
  • Due to improper pump selection (oversized)
  • Changing process requirements (throttling)
  • Piping changes
  • Addition of more pipe, elbows and valves
  • System head variations
  • Change in suction pressure, discharge head reqd
  • Buildup in pipes
  • Filter plugged
  • Automatic control valve shuts off pump flow
  • Change in viscosity of fluid
  • Parallel operation problems (starving one pump)

10
Impeller Radial Force At Any Flow
F (lbs.,Kg)
F K x H x S 2.31

D
K THRUST FACTOR H HEAD (ft, m) S
SPECIFIC GRAVITY D IMPELLER DIAMETER
(in.,cm) B IMPELLER WIDTH (in., cm)

B

11
SPECIFIC SPEED - K vs. CAPACITY
0.5
Ns (SI)
0.4
3500 (71)
0.3
K
0.2
0.1
0
0 20 40 60 80
100 120 140 160
PERCENT CAPACITY
12
PUMP SPECIFIC SPEED
  • CLASSIFIES IMPELLERS ON THE BASIS OF PERFORMANCE
    AND PROPORTIONS REGARDLESS OF SIZE OR SPEED
  • FUNCTION OF IMPELLER PROPORTIONS
  • SPEED IN RPM AT WHICH AN IMPELLER WOULD OPERATE
    IF REDUCED PROPORTIONALLY IN SIZE TO DELIVER 1
    GPM AND TOTAL HEAD OF 1 FOOT
  • DESIGNATED BY SYMBOL Ns
  • Ns RPM(GPM)1/2
  • H3/4
  • RPM SPEED IN REVOLUTIONS / MINUTE
  • GPM GALLONS /MINUTE AT BEST EFF. POINT
  • H HEAD IN FEET AT BEST EFF. POINT

13
PUMP SPECIFIC SPEED (Metric)
  • CLASSIFIES IMPELLERS ON THE BASIS OF PERFORMANCE
    AND PROPORTIONS REGARDLESS OF SIZE OR SPEED
  • FUNCTION OF IMPELLER PROPORTIONS
  • SPEED IN RPM AT WHICH AN IMPELLER WOULD OPERATE
    IF REDUCED PROPORTIONALLY IN SIZE TO DELIVER 1
    M3/h AND TOTAL HEAD OF 1 M
  • DESIGNATED BY SYMBOL Ns
  • Ns RPM(M3/h) 1/2
  • M 3/4
  • RPM SPEED IN REVOLUTIONS / MINUTE
  • M3/h CUBIC METERS PER HOUR AT BEST EFF.
    POINT
  • MH HEAD IN METERS AT BEST EFF. POINT

14
PUMP TYPE VS. SPECIFIC SPEED
HEAD
EFFICIENCY
HEAD, POWER EFFICIENCY
HEAD, POWER EFFICIENCY
HEAD, POWER EFFICIENCY
POWER
CAPACITY
CAPACITY
CAPACITY
CENTRIFUGAL
AXIAL FLOW
VERTICAL TURBINE
SPECIFIC SPEED, ns (Single Suction)
RADIAL-VANE
FRANCIS-VANE
MIXED FLOW
AXIAL FLOW

15
RADIAL FORCES ON IMPELLER
BEP
CUTWATER
RADIAL LOAD
125
BEP 100
FLOW
50
CAPACITY of BEP
150
SHUTOFF 0
Length of Line Force
16
THE IMPORTANCE OF ALIGNMENT
  • Any degree of misalignment between the motor and
    the pump shaft will cause vibration in the pump
  • Every revolution of the coupling places a load on
    the pump shaft and thrust bearing
  • At 3500 RPM, there will be 3500 pulses per minute
    applied to the shaft and bearing

17
MISALIGNMENT
MAY BE CAUSED BY
  • Pipe strain
  • Thermal growth
  • Poor foundation / baseplate
  • Improper initial alignment
  • System vibration / cavitation
  • Soft foot on motor

18
NET POSITIVE SUCTION HEAD (NPSH)One of the more
difficult characteristics to understand
  • In simplistic terms
  • Providing enough pressure in the pump suction to
    prevent vaporization of the fluid as it enters
    the eye of the impeller
  • Two values to be considered
  • NPSH available
  • Amount of pressure (head) in the system due to
    atmospheric or liquid pressure, height of suction
    tank, vapor pressure of the fluid and friction
    loss in the suction pipe

19
NPSH cont.
  • NPSH required
  • Pressure reduction of the fluid as it enters the
    pump
  • Determined by the pump design
  • Depends on impeller inlet, design, flow, speed
    and nature of liquid
  • NPSH available must always be gt NPSH required by
    a minimum of 3-5 feet (1-1.5m) margin

20
CAVITATION
  • Results if the NPSH available is less than the
    NPSH required
  • Occurs when the pressure at any point inside the
    pump drops below the vapor pressure corresponding
    to the temperature of the liquid
  • The liquid vaporizes and forms cavities of vapor
  • Bubbles are carried along in a stream until a
    region of higher pressure is reached where they
    collapse or implode with tremendous shock on the
    adjacent wall
  • Sudden rush of liquid into the cavity created by
    the collapsed vapor bubbles causes mechanical
    destruction (cavitation erosion or pitting)

21
CAVITATION cont.
  • Efficiency will be reduced as energy is consumed
    in the formation of bubbles
  • Water _at_ 70oF (20oC)will increase in volume about
    54,000 times when vaporized
  • Erosion and wear do not occur at the point of
    lowest pressure where the gas pockets are formed,
    but farther upstream at the point where the
    implosion occurs
  • Pressures up to 150,000 psi have been estimated
    at the implosion (1,000,000 Kpa)

22
RELATIVE PRESSURES IN THE PUMP SUCTION
E
D
B
A
C
TURBULENCE, FRICTION, ENTRANCE LOSS AT VANE
TIPS
INCREASINGPRESSURE DUE TO IMPELLER
ENTRANCE LOSS
FRICTION
POINT OF LOWEST PRESSURE WHERE VAPORIZATION
STARTS
INCREASING PRESSURE
A
B
C
D
E
POINTS ALONG LIQUID PATH
23
NET POSITIVE SUCTION HEAD
AVAILABLE
Hf
(friction in suction pipe)
PAtmospheric
Z
NPSH Available P Atm. - Pvap. pressure - Z - Hf
Correct for specific gravity All terms in feet
(meters) absolute
24
Results of Operating Off BEP
25
TEMPERATURE RISE
  • Overheating of the liquid in the casing can
    cause
  • Rubbing or seizure from thermal expansion
  • Vaporization of the liquid and excessive
    vibration
  • Accelerated corrosive attack by certain
    chemicals
  • Temperature rise per minute at shutoff is
  • T oF (oC) / min. HP (KW)so x K
  • Gal (m3) x S.G. x
    S.H.
  • HPso HP (KW) _at_ shutoff from curve
  • Gal. (m3) Liquid in casing
  • S.G. Specific gravity of fluid
  • S.H. Specific heat of fluid
  • Ex. Pump w/ 100HP (75KW) _at_s.o. , 6.8 gal casing
    (.03m3)
  • w/ 60oF (16oC) water would reach boiling
    in 2 min.
  • A recirculation line is a possible solution to
    the low flow or shut off operation problems....

26
CASING GROWTH DUE TO HIGH TEMPERATURE


27
IMPELLER CLEARANCE
  • Critical for open impellers
  • Normal setting .015 (.38mm) off front cover
  • High temperature requires more clearance
  • - Potential rubbing problem causes vibration
  • and high bearing loads
  • - Set impeller .002 (.05mm) addl clearance
  • for every 500 F (280C) over ambient temp.
  • Important for maximum efficiency

28
IMPELLER BALANCE
  • MECHANICAL
  • - Weight offset from center of impeller
  • - Balance by metal removal from vane
  • HYDRAULIC
  • - Vane in eye offset from impeller C/L
  • - Variation in vane thickness
  • - Results in uneven flow paths thru impeller
  • - Investment cast impeller eliminates
  • problem
  • - Careful machining setup can help

29

TYPICAL ANSI (or DIN) PROCESS PUMP
  • Small dia. shaft with excessive overhang
  • Stuffing box designed for packing
  • Shaft sleeve
  • Light to medium duty bearings
  • Rubber lip seals protecting the bearings
  • Snap ring retains thrust bearing in housing
  • Shaft adjustment requires dial indicator
  • Double row thrust bearing
  • Cast jacket on bearing frame for cooling
  • Small oil reservoir

30
ANSI (ISO/DIN) STANDARD PUMPS
  • Industry standards for dimensions based on
  • requirements for packed pumps
  • Shaft overhang a function of packing rings
  • and space for gland and repack accessibility
  • Clearance between shaft and box bore based
  • on packing cross-section
  • If most pumps today use mechanical seals -
  • why do we continue to use inferior designs
  • made for packing ??

31
BEARING OIL SEALS
  • Rubber Lip Seals Provided To Protect Bearings in
    standard ANSI pumps
  • Have life of less than four months
  • Groove shaft in first 30 days of operation
  • External contamination causes bearing failure

32
LIP SEAL LIFE
  • AUTOMOBILE
  • 100,000 Miles _at_ 40 Miles /hr. 2500 hrs. of
    operation
  • PUMP
  • 24 hrs./day x 365 days / year 8760 hours
  • 60 of lip seals fail in under 2000 hours
  • Lip seals may be fine for automobiles, but not
    for pumps

33
THRUST BEARING SNAP RING
  • Thrust bearings in standard ANSI pumps are held
    in place with a snap ring
  • Snap ring material harder than bearing housing
  • Wear in bearing housing results in potential
    bearing movement
  • Difficult to remove and install
  • If installed backwards - potential loose bearing


34
SIMULTANEOUS DYNAMIC LOADS ON PUMP SHAFT
35
SHAFT DYNAMICS
  • Radial movement of the shaft occurs in 3 forms
  • Deflection - under constant radial load in one
    direction
  • Whip - Cone shaped motion caused by unbalance
  • Runout - Shaft bent or eccentricity between shaft
    sleeve and shaft
  • It is possible to have all 3 events occurring
    simultaneously
  • ANSI B73.1 and API 610
  • Limit radial deflection and runout of the shaft
    to 0.002 T.I.R. at the stuffing box face(0.05mm)
  • Solid shafts are critical for pump reliability
  • Eliminate sleeve runout
  • Improved stiffness

36
SHAFT DEFLECTION
  • Shaft deflects because of unbalanced radial
    loads on the impeller
  • Shaft revolves on own centerline even when
    deflected
  • load is constant in direction and magnitude
  • Shaft stays bent as long as operating conditions
    remain the same

37
Shaft Whip
  • Shaft changes 180o from its centerline
  • every revolution
  • Usually caused by unbalanced impeller
  • Heavy side of impeller on same side of shaft
  • Whip and deflection can occur at same time
  • Moved to one side by the amount the shaft
    deflects

38
PUMP FAILURE ANALYSIS6 month period in a
typical process plant
39
OPTIMUM PUMP DESIGN
  • OBJECT
  • Create a better environment and greater
    stability for the dynamic pump components (seals
    and bearings) .to withstand the damaging forces
    inflicted upon them

40
SHAFT STIFFNESS
500 Lbs. (225Kg)
500 Lbs. (225Kg)
41
Derivation of Stiffness Ratio
Deflection of shaft
P Load E Modulus of Elasticity L
Length of Overhang PL3 I ? D4
3EI 64 PL3 L3
3E P D4 D4 64
I Moment of Inertia

cancel all common factors

42
Stiffness Ratio Examples
D
D
L
3
4
3
4
43
Stiffness Ratio Examples
D
L
D
L
3
4
3
4
1.87"
8"
L
/D
8
/(1.87)
512/12.23 42
3
4
3
4
L
/D
6
/(1.87)
216/12.23 17
1.87"
6"
44
Stiffness Ratio Examples
D
D
L
L
45
Stiffness Ratio Examples
D
D
L
L



L/D lt 2.4 Considered Adequate



46
LD PUMPS REDUCE BEARING LOADS
A
A Radial load on thrust bearing
100 Lbs.
B Radial load on radial bearing
100 lb. Impeller radial load on end of shaft
Standard
6 in.
8 in.
ANSI Pump
B
M
014(100)-6B
14006B
B233 lbs.
?
A
M
0 8(100)-6A
8006A
A133 lbs.
?
B
LD PUMP
M
011(100)-6B
11006B
B183 lbs.
?
A
A
M
0 5(100)-6A
5006A
A 83 lbs.
?
100 Lbs.
B
Radial Bearing
233 lbs. To 183 lbs.
6 in.
22 Reduction in Load
5 in.
2.1 x Improvement in Life
Thrust Bearing
B
133 lbs. To 83 lbs.
37 Reduction in Load
4 x Improvement in life
Bearing rating life varies inversely as the cube
of the applied load
47
LD PUMPS REDUCE BEARING LOADS(Metric)
A
A Radial load on thrust bearing
45.4. Kg
B Radial load on radial bearing
45.4 Kg Impeller radial load on end of shaft
Standard
152 mm
203 mm
ANSI (DIN/ISO) Pump
B
M
0355(45.4)-152B
16,117152B
B106 Kg
?
A
?
M
0 203(45.4)-152A
9,216152A
A61 kg
B
LD PUMP
M
0279(45.4)-152B
?
12,667152B
B83 Kg
A
A
?
M
0 127(45.4))-152A
5,766152A
A 38 Kg
45.4 Kg
B
Radial Bearing
106 Kg To 83 Kg
22 Reduction in Load
152 mm
127 mm
2.1 x Improvement in Life
Thrust Bearing
B
61Kg To 38 Kg
37 Reduction in Load
4 x Improvement in life
Bearing rating life varies inversely as the cube
of the applied load
48
MAXIMUM STIFFNESS RATIO
  • L3 / D4 RATIO
  • Less than 60 (Inch)
  • Less than 2.4 (Metric)

49
STIFFNESS RATIO CHART
50


STIFFNESS RATIO CHART - METRIC

51
EFFECTIVE PUMP OPERATIONAL ZONES
PUMP CURVE
BEP
A
HEAD
B
METRIC A
C
D
80
10
20
0
10
20
40
15
25
PERCENT OF BEP
FLOW
52
ALIGNMENT
  • EVERY TIME A PUMP IS TORN DOWN, THE MOTOR SHAFT
    AND PUMP SHAFT MUST BE REALIGNED
  • UNPROFESSIONAL OPTION TO RE-ALIGN USE A STRAIGHT
    EDGE
  • PROFESSIONAL OPTION IS TO USE DIAL INDICATORSTO
    MINIMIZE TOTAL RUNOUT
  • MODERN METHOD IS LASER ALIGNMENT WHICH IS VERY
    ACCURATE

53
PRESENT ALIGNMENT METHODS WEAKNESSES
  • All provide precision initial alignment
  • Degree of accuracy varies
  • Cost of system, training, and time involved in
    their use is dramatic
  • Time consuming (possibly 2 workers, 4-8 hrs.)
  • Difficult to compensate for high temperature
    applications
  • Requires worker skill, dexterity, and training to
    achieve accurate results
  • After pump startup, cannot insure continued
    alignment due to temperature, pipe strain,
    cavitation, water hammer, and vibration

54
MOTOR ADAPTER - WHAT IS IT?
  • Machined component that connects a pump power end
    to C face (D flg.) motor thru close tolerance
    fits on each end
  • Not a new technology
  • Used on machine tools and gear boxes
  • Operate with highest level of accuracy and
    precision
  • Mechanical seal in a pump is a high precision
    component
  • Mechanical seal accounts for 75 of pump downtime

55
MOTOR ADAPTER- ADVANTAGES
  • Provides easy, accurate, and reliable alignment
    during operation
  • Maintains near -laser alignment accuracy despite
    pipe strain, cavitation, high temperature, and
    vibration
  • A device that reduces vibration will prolong seal
    life and increase pump reliability
  • Reduces labor hours for initial installation
  • During teardown, maintenance cycle time is
    reduced dramatically
  • vertical mounting capability

56
MOTOR ADAPTER ADVANTAGES cont.
  • High temperature applications
  • Motor grows with the pump
  • More even temperature gradient across the pump
    and motor assembly
  • For high speed (3000/3600 RPM) applications -
    Alignment more critical
  • Disadvantages
  • Not as accurate as initial laser alignment due to
    inherent tolerance stackup of the various
    components

57
SEAL CHAMBERS
OLD STYLE
LARGE BORE

Designed for packing

Designed specifically for seals

Small radial clearances

20 Times greater fluid volume
-Seal contacting bore

Provides superior cooling,cleaning,

Limited fluid capacity
and lubrication for the seal
-Poor heat removal

Solids centrifuged away from seal

Easy to clog with solids

Eliminate seal rub problems
58
ELIMINATING SHAFT SLEEVES
  • Add no stiffness to shaft
  • Runout tolerance between shaft and sleeve
    compounds motion of seal faces in addition to
    deflection and shaft runout already present
  • Deflection must be a maximum of .002 at the
    seal faces, yet faces are lapped within 2 helium
    light bands
  • Deflection or motion at seal faces is 1000 times
    greater than the face flatness
  • Sleeves are necessary for packed pumps, but with
    todays new seals they serve no purpose

59
BEARING OIL SEALS
  • Three basic types
  • Lip seal
  • Inexpensive, simple to install, very effective
    when new
  • Elastomeric construction
  • Contact shaft and contributes to friction drag
    and temp. rise in bearing area
  • After 2000-3000 hours, no longer provide
    effective barrier against contamination
  • Will groove shaft

60
BEARING OIL SEALS cont.
  • Labyrinth seals
  • Required by API 610
  • Non-contacting and non-wearing
  • Unlimited life
  • Effective for most types of contaminants
  • Do not keep heavy moisture or corrosive vapors
    from entering the bearing frame (especially in
    static state)

61
BEARING OIL SEALS cont.
  • Face seals and magnetic seals
  • Protect bearings from possible immersion
  • Good for moisture laden environment
  • Expansion chamber should be used to accommodate
    changes in internal pressure and vapor volume
  • completely enclosed system (can be submerged)
  • Generate heat
  • Limited life

62
SYSTEM ONE LABYRINTH SEAL
63
BEARING LIFE
  • Bearing life calculations assume proper
    lubrication and an environment that protects the
    bearing from contamination
  • The basic dynamic load rating C is the bearing
    load that will give a rating life of 1 million
    revolutions
  • L10 Basic Rating Life is life that 90 of group
    of brgs. will exceed ( millions of revs or hrs.
    operation)
  • Rating Life varies inversely as the cube of the
    applied load
  • Reduction of impeller dia. from maximum improves
    life calculation by the inverse ratio of the
    impeller diameters to the 6th power

64
BEARING LIFE cont.
  • 90 of all bearings will fail prematurely and
  • not reach their rated L10 life
  • - Calculated life by design over 20 years
  • - Actual life maybe 3 years
  • Failures
  • -Fatigue due to excessive loads (20-50 of
    failure)
  • -Lube failure - excessive temperatures
  • contaminants
  • -Poor installation

65
BEARING LUBRICATION FAILURE
  • OXIDATION
  • Chemical reaction between oxygen oil
  • New compounds produced which deteriorate the
  • life of oil and bearings
  • Reaction rate increases with the presence of
    water
  • and increases exponentially with temperature
  • CONTAMINATION
  • Water breaks down lube directly reducing brg.
  • life - .003 water in oil reduces life of oil
    50
  • Oil life decreases by 50 for every 20oF (11oC)
  • rise in temp. above 140oF (60oC)

66
SYNTHETIC OILS
  • Lower change in viscosity with temp. change
  • -One synthetic can take place of several oils
  • Provides good lube at high temps. 300oF (160oC)
  • -Does not oxidize (breakdown)
  • At low temps.- good fluidity boosts efficiency
    and
  • reduces component wear during cold weather
  • Achieves full lubrication quickly
  • Offers longer life - less consumption
  • Lasts 1.5-2 times longer than conventional oils
  • Maintains lube properties with water
  • contamination better than mineral oils

67
BEARING CLEARANCES
Normal clearance C3 6310
Radial Bearing (microns) Radial
.0003-.0011(9-30) .0009-.0017(27-51) A
xial .0016-.003 (48-90)
.0016-.003(48-90) 5310 Double Row Thrust
Bearing Radial .0005-.0014(15-42)
.0014-.0020(42-60) Axial
.0005-.0014(15-42) .0014-.0023(42-69)
7310 Angular Contact Thrust Bearing Axial
-.0003 to .0003 (line to line) NOMINAL
0 Radial approx .85 x Axial
68
ANGULAR CONTACT BEARINGS
  • Used as thrust bearing in pairs (also carry
    radial load)
  • Mounted back to back (letters to letters)
  • Provides maximum stiffness to shaft
  • Avoid ball skidding under light loads
  • Small preload eliminates potential
  • Line to line design clearances
  • Shaft fit provides preload
  • Eliminates shaft end play
  • Greater thrust capacity
  • Required by API 610 Specification

69
BEARING PRELOAD
  • Pump radial bearings have positive internal
    clearance
  • Thrust bearings can be either positive or
    negative clearance ( 5310 vs. 7310 pr.)
  • Preload occurs when there is a negative
    clearance in the bearing
  • Desirable to increase running accuracy
  • Enhances stiffness
  • Reduces running noise
  • Provides a longer service life under proper
    applications

70
BEARING CLEARANCES / PRELOAD
LIFE
Clearance
Preload
71
MICROMETER IMPELLER ADJUSTMENT
  • Micrometer adjusting nut allows impeller to be
    set to precise clearance from the front of the
    casing
  • Each line on the adjusting nut is a .003
    (.08mm) graduation for axial movement of the
    shaft
  • Normal setting is .015 (.38mm) from the casing
    face
  • For every 50 deg. above 100 deg. fluid temp...
    add .002 clearance

72
GOAL IMPROVED PUMP AND MECHANICAL SEAL
RELIABILITY
  • Eliminate or reduce mechanical and environmental
    influences that cause pump and seal problems
  • Specify proper pump design criteria to minimize
    the impact of mechanical and environmental
    influences
  • Specify proper mechanical seal and environmental
    controls to maximize seal life

73
OPTIMUM PUMP DESIGN SUMMARY
  • Low L3D4 ratio as possible
  • Solid shaft ( no sleeves)
  • Large bore seal chamber
  • Large oil capacity bearing housing
  • Angular contact thrust bearings
  • Retainer cover to hold thrust bearing (no snap
    rings)
  • Fin tube cooling for bearing housing
  • Labyrinth seals
  • Positive / precision shaft adjustment method
  • Investment cast impellers
  • Magnetic drain plugs in oil sump
  • C Frame motor adapter
  • Centerline support for hot applications

74
REQUIREMENTS FOR PROPER EMISSION CONTROL AND
MAXIMUM SEAL LIFE
  • Shaft runout at impeller within .001 T.I.R.
    (.03mm)
  • Coupling alignment within .005 T.I.R. on rim
    face (.13mm)
  • Operation of the pump at or close to best
    efficiency point (definition dependent upon pump
    size, speed, and LD ratio)
  • NPSH available to be at least 5 feet (1.5m)
    greater than NPSH required
  • Proper foundation and baseplate arrangement
  • Absolute minimum pipe strain on suction and
    discharge flanges
  • All impellers dynamically balanced to ISO G 6.3
    spec.
  • Face of seal chamber square to shaft within .002
    T.I.R. (.05mm)
  • Seal chamber register concentric to shaft within
    .003 T.I.R. (.08mm)
  • Shaft end play less than .0005 (.015mm)

75
SYSTEM ONE PUMP WARRANTY
  • ONE YEAR FOR MECHANICAL SEAL
  • SPARE SEAL KIT OR REBUILT SEAL OFFERED
  • FIVE YEARS ON SYSTEM ONE POWER END
  • ANY FAILURE INCLUDING BEARINGS
  • FREE REPLACEMENTS OF FAILED COMPONENT
  • SHAFT WARRANTIED FOR LIFE ON FRAME S AND A PUMPS
  • free replacements are one time only
About PowerShow.com