Alignment and Levelling Flashcards

What is the purpose of an alignment target window specification?

Answer: To define the intentional cold offset values that account for thermal growth at operating temperature

The alignment target window specifies intentional offset values to be applied during cold alignment that compensate for differential thermal growth between machines, ensuring the shafts are collinear when both machines reach operating temperature.

In a multi-element machine train (e.g., motor-gearbox-pump), what is the correct alignment sequence?

Answer: Start with the fixed machine (usually the driven end) and work back toward the driver

In a multi-element train, alignment begins with the most constrained (fixed) machine — typically the driven equipment connected to process piping — and proceeds back through the train, aligning each successive coupling to the established reference.

What is geometric measurement of equipment used for in millwright work?

Answer: Checking dimensions such as flatness, squareness, parallelism, and concentricity of machine components

Geometric measurement involves checking critical dimensional relationships of machine components — flatness of surfaces, squareness of flanges, parallelism of ways, and concentricity of bores — to ensure proper assembly and operation.

What is the function of a wire alignment (piano wire method)?

Answer: To establish a straight reference line over a long distance for aligning multiple bearing pedestals

The piano wire method uses a taut, thin wire stretched between two fixed points to establish a straight reference line. Measurement from each bearing pedestal to the wire determines if the pedestals are in proper alignment.

How does vibration analysis help verify alignment quality after an alignment job?

Answer: It detects misalignment-induced vibration signatures such as 2× radial and 1× axial components

Vibration analysis reveals misalignment signatures: radial vibration at 2× running speed indicates offset misalignment, and axial vibration at 1× running speed indicates angular misalignment. Post-alignment vibration checks confirm the alignment is within acceptable limits.

When grouting a baseplate, why is it important to achieve full contact between the grout and the underside of the baseplate?

Answer: To provide a solid, void-free support that evenly distributes loads and prevents vibration

Full grout contact ensures uniform load distribution from the machine through the baseplate to the foundation, prevents flexing and vibration, and maintains long-term alignment stability. Voids under the baseplate cause uneven support and alignment problems.