How Do You Measure A Coupling Alignment?

How can coupling alignment be checked?

The necessary tools used for checking the alignment of a flexible coupling are a straightedge and a taper gauge or a set of feeler gauges, or by use of dial indicators. A rough check for angular alignment is made by inserting the taper gauge or feelers between the coupling faces at 90 degree intervals (see Image 2).

What is the most accurate method of coupling alignment?

Laser alignment
Laser alignment is the most accurate method available (to 0.0001) and once familiar staff can align the pump and motor quickly. However, it is the most expensive method available and can be complicated to set up.

How do you align a coupling?

A coupling is correctly aligned if a straight-edge laid across both coupling halves parallel to the shaft maintains the same distance from the shaft at all points around its circumference. In addition, the axial distance between the coupling halves should remain the same at all points around the circumference.

How do you calculate alignment reading?

Calculating the Front Feet and Rear Feet Positions

1. Face TIR = Total Indicator Reading from the Face Dial.
2. Rim TIR = Total Indicator Reading from the Rim Dial.
3. A = the diameter of the face dial indicator travel.
4. B = the distance from the Rim dial indicator plunger to the movable machine’s front feet bolt center.

Which tool would be used to check that the alignment is correct by measurement of the gap between the coupling faces?

feeler gauge
Using the feeler gauge or a vernier caliper the engineer accurately measures any gap between the coupling halves.

How do you check a shaft misalignment?

Measuring different sections along the horizontal and vertical planes will help determine shaft misalignment and whether the misalignment is angular, parallel, or often both. Phase analysis offers the most precises diagnose of misalignment.

What are the four types of alignment?

There are four main alignments: left, right, center, and justified.

What are the methods for shaft alignment?

Methods of Shaft Alignment

• Straight Edge Alignment.
• Rim-Face Dial Indicator Alignment.
• Reverse Dial Indicator Alignment.
• Laser Alignment.

What is the maximum misalignment on a coupling?

Each coupling is designed to transmit a given limiting torque. Generally, flexible couplings are able to tolerate up to ±3 degrees of angular misalignment and up to 0.75 mm parallel misalignment depending on their design. If more misalignment is required, a universal joint can be used (see Figs.

How do you calculate axial misalignment?

To determine angular misalignment, divide the coupling gap difference by the diameter of face dial indicator travel. Example: The face indicator is set to zero at 3:00. The indicator is rotated 180 degrees to 9:00.

What is bar sag in alignment?

Sag (also called bar sag) is the result of gravity acting on the overhung hardware spanning across the coupling that holds the indicator(s). It is always present, and its magnitude and repeatability must be accurately measured and known for the millwright to have any hope of measuring the misalignment accurately.

How often should pump alignment be checked?

Systems should be checked for shaft alignment during installation, at frequent intervals during operation, and after service and maintenance.

What measuring instrument shall we use to get the difference alignment of the shaft?

Dial-indicator systems
Dial-indicator systems are the most useful because they can be used to measure shaft runout, bearing alignment, and soft foot directly.

How do you ensure the alignment of shaft before fixing coupling bolts in a flange?

Before starting the alignment, the MASTER must be decided. The other machine must be moved to align the shafts. First take the dial indicator readings on the pump coupling and then the readings on the motor coupling. On a sheet of graph paper, layout the equipment being aligned.

How is misalignment measured?

Measurement of Misalignment
By measuring your shaft alignment from different points along the horizontal and vertical planes, you can determine exactly how far out of alignment your shafts are and whether you are dealing with angular misalignment or offset (parallel) misalignment or, typically, both.

What are the two main types of misalignment?

The main types of misalignment are angular, radial, and axial displacement. Factors that influence misalignment include thermal imbalances, wear, settlement and creep, and the influence of the last of these can, without correct maintenance, increase during the life of the coupling.

Which of the following coupling allows slight misalignment of shaft?

Elastomeric – Elastomeric couplings use an elastomer, or flexible element, to provide sliding motion between coupling components, thereby minimizing friction, and allowing for slight misalignment.

How do you check a coupling alignment with a dial gauge?

To measure vertical misalignment, perform the following steps:

1. Rotate the dial indicators to 6:00.
2. Set the face dial indicator to read zero.
3. Set the rim dial indicator to the sag value.
4. Rotate both shafts (if possible) to 12:00.
5. Record the DIR and DIF dial indicator TIR values.

What is reverse dial alignment?

Reverse alignment is the measurement of the axis, or centerline, of one shaft to the relative position of the axis of an opposing shaft centerline.The centerline measurements are taken in both horizontal and vertical planes (Figure 1).

What are the types of misalignment?

There are two types of misalignment: offset or parallel misalignment and angular, gap, or face misalignment. With offset misalignment, the center lines of both shafts are parallel but they are offset. With angular misalignment, the shafts are at an angle to each other.