All acid storage tanks, drying towers, absorption towers, and lines shall be vented, cleaned, purged and tested for explosive mixture before welding, burning or cutting on them is permitted.
Ariz. Admin. Code § R11-1-1505
All acid storage tanks, drying towers, absorption towers, and lines shall be vented, cleaned, purged and tested for explosive mixture before welding, burning or cutting on them is permitted.
Ariz. Admin. Code § R11-1-1505