Gas transmission · Class location & MAOP cascade · 49 CFR 192.5
Class Location Reassessment
Determines the current class location from the building count and flags within the sliding 1-mile class location unit per 49 CFR 192.5, compares it to as-built, and flags the §192.609/611 study & MAOP cascade when the class rises.
Class Location Unit Survey
count
As-Built
Engineering Basis
Class location unit = 220 yd either side of the centerline over any continuous 1-mile sliding length (§192.5).
Class 1 ≤10 buildings · Class 2 11-45 · Class 3 ≥46 or within-100-yd ≥20-person concentration · Class 4 ≥4-story prevalent.
A class increase triggers the §192.609 study and §192.611 MAOP confirmation/revision.
Design factor F (§192.111): Class 1 0.72 (0.80 under §192.112), Class 2 0.60, Class 3 0.50, Class 4 0.40 — a lower F may force MAOP reduction or pipe replacement.
May invoke the §192.624 MAOP-reconfirmation cascade in HCA / Class 3-4.