Bearing defect frequencies
BPFO, BPFI, BSF and FTF from bearing geometry and shaft speed, with the harmonics and the minimum spectrum Fmax you need to see them.
Facilities & integrity
B31G remaining strength of a corroded pipe
A metal-loss defect assessed by both original and modified B31G, giving the failure pressure, the safe operating pressure and the longest defect your MAOP can carry.
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How it is calculated
- Original B31G: parabolic defect area, flow stress 1.1·SMYS, Folias factor M = √(1 + 0.8z) with z = L²/(Dt); for z > 20 the defect is treated as infinitely long.
- Modified B31G (0.85 dL): flow stress SMYS + 10 ksi and the two-part Folias factor, which is the form normally used today.
- Safe operating pressure is the failure pressure times the design factor you set.
- The allowable defect length is found by marching the length out until the safe pressure falls below MAOP.
Standards it speaks
Where this stops being true
B31G is a Level 1 screening method for blunt, isolated, internally or externally corroded areas in ductile pipe under internal pressure only. It does not apply to cracks, gouges, dents, girth-weld defects, seam defects, or corrosion in a bend or under external loading — and it assumes the defect profile is a single smooth patch, where a real corrosion cluster has to be assessed as interacting defects. A pipe that fails B31G is not necessarily unfit; it is a candidate for a Level 2 effective-area or Level 3 finite-element assessment, which routinely clears pipe that B31G rejects.
The capability that automates this
- FA-04Corrosion & Pipeline IntegrityPredicts where a line is corroding fastest and how long it has left, so inspection and replacement go where the risk actually is.
- FA-05Risk-Based Inspection PlanningAllocates a fixed inspection budget to the equipment where failure would hurt most and is most likely, with the reasoning written down.
Related tools
Corrosion rate & remaining life
Two thickness readings turned into a short-term and a long-term rate, a remaining life and the next inspection date API 510 and 570 would set.
Pipe wall thickness & MAOP
Required wall thickness and maximum allowable operating pressure under B31.3, B31.4 or B31.8, with the class location, joint and temperature factors applied.
Pipeline pressure drop
Single-phase liquid by Darcy–Weisbach with a real Colebrook friction factor, and gas by Weymouth with both Panhandle equations alongside it.