Zone 0/1/2 extent-of-classification around lighter-than-air gas/vapor sources — compressor shelters and general process locations (API RP 505, §9.2.2)
◉ API RP 505 §9.2.2 STYLE CHECK · NOT A REGULATORY SUBMISSION TOOL
⚠ Indicative tool only, and the geometric mirror-image of the existing Process Equipment Point Source calculator. That tool covers heavier-than-air sources, which sink and spread laterally at grade (7.5m in every direction). This one covers lighter-than-air sources, which rise — the zones extend primarily upward (7.5m) with a smaller, capped lateral/downward extent (4.5m maximum or to grade). Verified directly against Figures 23–26 of this edition. Distances are for typical refinery installations and must be used with judgment.
Identification
Research entries stay private to you for practice/testing. Switch to Official once this is a real design your company should see.
Source Configuration (§9.2.2)
Note (§9.2.4.1): cooling tower pump pits in otherwise unclassified locations need no separate classification — cooling tower pumps aren't considered a source of release.