Mod 8 - Alignment & Balance

Module from the Rotating Equipment Training Curriculum curriculum.

ALIGNMENT & FIELD BALANCING · Learning Objectives · 1. Perform shaft alignment using laser and dial indicator methods 2. Apply API 686 alignment tolerances 3. Correct soft foot conditions before alignment 4. Execute single-plane and two-plane field balancing · Alignment Methods Comparison

Method	Accuracy	Equipment Cost	Setup Time	Skill Level	Best For	Notes
Straightedge/Feeler	±0.020 in	$50	10 min	Low	Rough alignment, non-critical	Not acceptable for API 610 pumps
Rim-and-Face Dial	±0.001 in	$200-500	45-90 min	Medium	General purpose, legacy plants	Requires sag compensation at distance
Reverse Indicator Dial	±0.001 in	$300-600	30-60 min	Medium-High	Better accuracy than rim-face, detects soft foot	Two setups required, good for large machines
Laser (single-beam)	±0.0005 in	$5,000-10,000	15-30 min	Medium	Standard for API 610/617 equipment	Fastest, most repeatable, calculates shim changes
Laser (dual-beam)	±0.0005 in	$8,000-15,000	15-30 min	Medium	Same as single + real-time move monitoring	Premium option, shows live corrections
API 686 Alignment Tolerances
Speed (RPM)	Offset (mils)	Angularity (mils/inch)	Notes	Coupling Type	Measurement
<1800	±4.0	±1.0	Standard tolerance for slow-speed equipment	Any	Both directions (H and V)
1800-3600	±2.0	±0.5	Standard for most process pumps and motors	Flexible element	Both directions
3600-7200	±1.0	±0.25	High-speed equipment — tight tolerance	Flexible element or gear	Both directions + axial
>7200	±0.5	±0.125	Turbomachinery — precision alignment required	Gear or diaphragm	Proximity probe verified
Source: API 686, FOS Chief Files — Compressor & Pump folder, IPE-EP-6-1-1, IPE-EP-6-3-1

Source: Rotating_Equipment_Training_Curriculum_v1.xlsx · Sheet: Mod 8 - Alignment & Balance

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