Basic of Aligment

2. MACHINERY ALIGNMENT
API 686
Presented by
M. Asif
SO-PM III

3. Table of Contents
 (a) What is Alignment
 (b) What is Misalignment
 (c) Types of Misalignment
 (d) Method of Alignment
 (e) Symptoms of Misalignment
 (f) Pre Alignment Checks
 (g) Tools Required For Alignment
 (h) Alignment Tolerances

4. What is Machinery/Shaft Alignment?
Its the process of positioning of two or more machines that
are coupled, so that centre lines of rotating shafts form a
single line
when the machines are under normal operating conditions.

5. Aligning Your Machinery Mean…
performance and protection
of industrial equipment.
Increase operating time.
Increase production
Cost saving

6. What is Misalignment & Types
 Misalignment is the deviation of relative shaft
from collinear axis of rotation when equipment is
running at normal operating conditions.
 Shaft misalignment occurs when the center lines of
coupled shafts do not match up.
 There are two Types of misalignment.
Offset/Radial Misalignment
 Angular /Axial Misalignment

7. Radial Misalignment
 Radial misalignment can also sometimes be referred to
as parallel misalignment because the two shafts, or
axes, are parallel but do not line up.
 Radial Misalignment can be further classified as
 Radial Vertical Misalignment
 Radial Horizontal Misalignment

8. Axial Misalignment
 Axial/Angular misalignment involves an angle
just as the name implies. It occurs when one of
the shaft axes is at an angle in relation to the
other.
 Axial Misalignment can also be classified as
 Axial Vertical Misalignment
 Axial Horizontal Misalignment
 Combination

9. Misaligned Your Machinery Mean..
Is a risk to your business.
Lead to unplanned
production stops.
Consume more power.
Can affect the quality of
the product you are
manufacturing.
Financial loss.

10. Types of Misalignment
■ Parallel Displacement or Radial Displacement
■ Face Displacement or Angular Displacement
■ Combination

11. Method of Alignment
 Rough Alignment
 1 = Straight Edge ,steel rule & Wire Method
 Precision Alignment
 2 = Rim & Face Method
 3 = Reverse Method/Graphical Method
 4 = Laser Method

12. Method of Alignment

13. Symptoms of Misalignment
■ Premature bearing, seal, shaft and coupling failure
■ High vibration
■ High Casing / Bearings / Oil Temperatures
■ Excessive oil leakage from bearing seals
■ Coupling is hot
■ Foundation bolts get loosen
■ Coupling bolts/Shims broken or loosen
■ Shafts are breaking (or cracking) at or close to the
inboard bearings or coupling hubs
■ Similar machine has less vibration

14. Effects of Misalignment
Misalignment can cause the following problems on the
running machine.
 Vibration in the machine and associated / linked
equipment’s.
 Excessive wear and temperature rise in the bearings.
 It causes coupling failure.
 Abnormal noise arises
 Over loading of prime movers
 Decreases the efficiency of the machine

15. Causes of Misalignment
 Thermal Expansion
 Stress.
 Soft foot.
 Bearing Failure.
 Vibration.
 Poor workmanship.

16. Mechanical Causes of Vibration
 Unbalanced rotating components. Damaged impellers
 A bent or warped shaft.
 Misalignment
 Pipe strain. Either by design or as a result of thermal
growth.
 Thermal growth of various components, especially shafts.
 Rubbing parts.
 Worn or loose bearings.
 Loose hold down bolts.
 Loose parts.
 Damaged parts.

17. Why Precise Alignment is needed?
■ Now trend in industry is towards higher speeds,
higher horsepower and less sparing.
■ These factors increases the need of precise alignment
and balancing to minimize vibration and premature
wears of couplings, bearings and shaft seals.
■ Stresses from misalignment are directly
proportional to the speed of unit.

18. Alignment States
 Cold Alignment
Alignment which is carried out when the
machine is at cold state.
 Hot Alignment
Alignment which is carried out when the
machine is at hot state.

19. Pre-Alignment requirements?
■ Foundation
■ Grout
■ Base plate
■ Piping
■ Coupling Installation
■ Soft Foot
■ Shims
■ Sag
■ Feeler gauge

20. Foundation
 Adequate size and good
condition
 Thumb Role
 Concrete weight should be
equal to three times
machine weight for rotating
machines
 Concrete weight should be
five times for reciprocating
machines

21. Grout
■ Should be in good condition
■ Tapping with a small hammer can detect
hollow spots

22. Base Plate
■ Should be rigid
■ Machine mounting pads should be level flat
and clean.
■

23. Piping
 Well fitted and
supported.
 Stress Free.
 Sufficiently flexible, no
more than 0.08mm
vertical and horizontal
movement occurs at
coupling

24. Coupling
 The coupling should
be installed with a
light interference fit
with shaft.
 Vary from .002”to
.005”per inch of the
shaft diameter.

25. Soft Foot
■ Machine feet do not rest flatly on the base of machine.
■ Soft foot is caused by deformed machine base plates
or deformed machine feet.
■ This method is commonly used for soft foot
check & correction.
■ Place the Dial at foot of machine.
Q Tighten all hold down bolts then loosen one bolt
at a time and note the deflection
■ Maximum soft foot allowable limit is 0.05mm

26. SOFT FOOT

27. Shims
■ The shims used should be large enough to
adequately support each foot.
■ Don’t use Dirty shims-Clean them
■ Many shims replace with fewer thick shims
■ Use Pre-cut stainless steel shims
■ Don’t reuse painted, or badly bent shims
■ Best choice for shim material is stainless steel
■ Maximum shim limit is12mm
■ Try to use max 5 or less shims under each foot.
Its not always possible but try to minimize

28. SAG
 The Inclination towards downwards in alignment
Bracket due to gravitational force is called
Bracket Sag .
Sag does not normally effect horizontal alignment.
 But in vertical measurement it depends on the
spacer length
 Q For less then 6” length of the spacer sag is
negligible.
 Q For spans greater then 6” sag should checked &
Note down.

29. SAG CHECK
Dial Travel

30. Thermal Growth
■ For liquids 93 C° and below set motor shaft at same
height as pump shaft.
■ For liquids above 93 C°, set pump shaft lower or motor
shaft higher as per OEM Recommendation.
■ For foot mounted pumps or turbines
Q Thermal growth (mils) = 6x [ To-Ta] xL/100
Q L = distance from base of shaft tofoot
Q To =operating temperature C°
Q Ta =ambient temperature C°
Note: Apply these formulas only if alignment data is not
given by OEM

31. Overhung Pump Radial Flange Bolts
■ Some times these bolts are use for achieving
alignment better procedure is to bring all bolts to
light torque and then continue to full tightness
while observing with dial indicator such that no
shaft lateral movement occurs.
Example =AMU-P-101A/B
Note: Normally experienced person do not recommend this method

32. Tools req’d for Machinery alignment
■ Dial Indicator (two dials)
■ Two brackets (for reverse indicator method)
■ Straight Edge/Steel Rule,
■ Meter tape
Venire Caliper
■ Micro meter
■ Inspection Mirror
■ Crowbar
■ Tool Box
■ Shims

33. Alignment with Straight edge/Feeler Gauge.
Allowed only on flexible coupling, as precise
alignment can not be achieved.
Radial misalignment is checked / corrected with the
help of straight edge or knife edge.
Axial misalignment is checked / corrected with the
help of feeler gauge & ID Mic.
This method is used only for aligning the shafts of
non critical machines.
Alignment Methods (Cont.)

34. Pulleys /Sprockets Alignment
With Steel Rule/Straight Edge
V Belt pulleys or sprockets can be aligned with straight edge
bars/Steel Rule or strings.

35. In this method, as the name suggests, graphical techniques are used for
aligning the rotating members. One set of readings is taken from the
loose machine to the fixed machine, and the second set of readings is
taken from the fixed machine to the loose machine. It is therefore
sometimes referred as reverse method.
These readings are then plotted on the graph using suitable scale. How
much the rotating members are misaligned, can then be calculated from
the graph.
Graphical or Reverse method

36. Graphical Method
Movable
Machine
X Z
Fixed
Machine
D2
Y
Only one of above indicator orientations will allow you to graph the
shim changes in such a manner that a positive indicator reading always
means to plot up and a negative indicator reading always means to plot
down,
D1

37. Advantages:
More accurate than Rim & Face Method.
Readings are not affected by axial float.
Disadvantages:
Should not be used on close coupled shafts.
Difficult to take readings on long shafts
Advantages & Disadvantages Reverse
Method

38. Laser Method
The most modern & accurate method for aligning
the shafts.
Laser alignment is the process of determining
misalignment by a laser beam.
Where laser is mounted on one shafts and a
receiver or reflector is mounted on the other.
Both shafts are turned at the same time. The
deviation in the laser beam is measured as the shaft
is turned and readings show on Display Unit.

39. Laser Alignment kit Parts
1 Display unit
2 Cell or batteries
3 measuring units with spirit
levels
4 mechanical shaft fixtures
5 locking chains with
tightening pin
6 Measuring tape (imperial
and metric)
7 Machinery shim starter kit
8 USB communication cable
9 Quick Start Guide
10 Printed User Instructions
11 Hard carrying case
12 Informational Cd

40. For using dial indicators, it is necessary to prepare a
suitable Fixture, which can hold two or three dial indicators
One dial indicators (R), with the axis in the radial direction,
will measure the radial misalignment of the shafts. And one
dial indicator (A) with the axis in the axial direction, will
measure the axial misalignment of the shafts.
Rim & Face Method

41. Dial Indicator works with the index of
mm scale. Before rotating the shaft and
collecting the misalignment data, ensure
that all the dial indicators are set to zero.
Also make sure that traveling margin is
available in these indicators.
When recording the data, the plus sign
shall be given when the rod of the dial
indicator goes back into its seat or move
inward. Minus sign shall be given when
the rod comes out.
When the dial indicator main pointer
rotates by 3600, the dial indicator small
pointer will show 1mm displacement of
the rod
Dial Indicator

42. ACCURACY VERIFICATION
■ Each time the dial indicator is rotated to the
top location it should display a reading of zero.
■ If it does not then something has moved during
the rotation: indicator, bracket, clamping
mechanism, machine. Correct the problem and
start over.
■ Another test, which can be performed as the data
is collected, is to verify that the sum of the top
and the bottom readings should equal the sum of
the left and right readings.

43. Place the dial on the rim & Face of the coupling hub and
secure it with the help of suitable Fixture.
Measure the data during a rotation of 3600 The algebraic
sum of the values read on the horizontal plane (900 & 2700)
will be equal to the values read on the vertical plane (00 and
1800).
Rim & Face Method

44. To perform the Rim & Face Method, By Formula you
must:
•Mount the dial indicators fixtures.
•Measure the A, B, & C dimensions.
•Obtain as-found readings.
•Determine the vertical foot positions.
•Make vertical corrections.
•Make horizontal corrections.
•R e-measure and record final alignment values.

45. F=0.3/2 + 0.8x465/-150
0.15+2.48=2.63mm
R=0.3/2+ 0.8x1255/-150
0.15+6.693=6.84mm

46. Advantages:
Good for large dia coupling hubs where the shafts are close together.
To be used where one of the shafts can not rotate during alignment.
Easy to use.
Disadvantages:
Difficult to take face readings, if there is axial float in the shaft
Requires removal of coupling spool.
More complex alignment calculation
Too much manual work
Indicator Sag
Advantages & Disadvantages of Rim & Face Method

47. Comparison

48. Important Tips
 Clean the Machine Base, Removes Rust, burrs etc.
 Perform pre-alignment checks on machine
 Use correct bolt tightening procedure.
 Use jack bolts
 Try to put the stem of dial gauge perpendicular to the
surface of coupling hub
 Check indicator sag
 Check Run out of(Bent shaft, Out of round couplings)
 Check the coupling gap

49. Important Tips
 After decoupling the machine, take alignment reading, if
time permits. It serves as a reference reading, as some time
it becomes difficult to get the desired readings.
 Before alignment, always ensure that there is no “soft
footing” in the machine. If it exists, remove it prior to align.
 Use Jacking Bolts For move the Motor Never use Hammer
 If the machine has more than four feet, then it is better to
carry out the alignment of the machine by reverse /
graphical method.
 Always carry out the alignment job in the early day time.
NOTE Down the Time while taking the final Readings

50. Alignment Tolerances
Parallel Angular
RPM mm Inch RPM mm Inch
0 - 1000 0.13 0.0051" 0 - 1000 0.10 0.0039"
1000-2000 0.10 0.0039" 1000-2000 0.08 0.0031"
2000-3000 0.07 0.0027" 2000-3000 0.07 0.0027"
3000-4000 0.05 0.0019" 3000-4000 0.06 0.0023"
4000-Above 0.03 0.0011" 4000-Above 0.05 0.0019"
NOTE: These tolerance should be used were manufacturer recommended
tolerances are not available.

51. FINISH