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Shop-Fabricated Tank Inspection. Chris Bashor Minnesota Pollution Control Agency June, 2001. Shop-Fabricated Tank Inspection. History of States-EPA Workgroup Interest STI Standard SP001-00 Comparison with API 653 Relevance of SP001-00 to States and EPA Issues Conclusions.
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Shop-Fabricated Tank Inspection Chris Bashor Minnesota Pollution Control Agency June, 2001
Shop-Fabricated Tank Inspection • History of States-EPA Workgroup Interest • STI Standard SP001-00 • Comparison with API 653 • Relevance of SP001-00 to States and EPA • Issues • Conclusions
History of States-EPA Workgroup Interest • EPA identifies SPCC need: no industry standard for inspection of small tanks • Steel Tank Institute develops draft standard • Workgroup reviews draft standard at May 2000 meeting and submits comments • Final STI standard: September 2000
STI Standard SP001-00 • Steel Tank Institute • Applicability • Periodic inspections • Certified inspections
Steel Tank Institute • www.steeltank.com • Contact: Dana Schmidt 847-438-8265 • Paper copies available for $35 • Electronic version was emailed to states
Applicability • Shop-fabricated ASTs (up to 50,000 gal) • Built to national standard (e.g. UL142) • Storage of “noncorrosive, stable, flammable, and combustible liquids having specific gravity not exceeding that of water” • Includes foundation and vents, but not piping
Applicability (cont) • Can be used for double-walled tanks • Elevated or not, horizontal or vertical, manway or not • MN believes standard is applicable for the most part to tanks of these types storing most other liquids, even if non-standard construction • Corrosive liquids need special attention
Periodic Inspections • Qualifications: owner or any employee (no training) • Monthly: water draw; DW interstitial space; pipe connections • Quarterly: “walk-around” for damage, external coating, cleaning, repairs, vents
Periodic Inspections (cont) • Annually: proper drainage, foundation • Other: recordkeeping checklists, diagrams, maintenance info, references
Certified Inspections • Qualifications: • API 653 certified • STI certified • Frequency: every 10 years, or more often based on calculated minimum remaining wall thickness
Certified Inspections (cont.) • Procedures: • All visual per periodic checklists • Pressure test for tightness • Shell inspection
Certified Inspections (cont.) • Shell inspection methods depend on whether tank is single or double-walled, elevated or not, has manway or not, has cathodic system or not • Procedures include: • Ultrasonic thickness testing (criteria given) • Visual inspection (minimal criteria given) • ASTM G 158 • NACE RP-0285
Comparison with API 653 • In general, SP001-00 is much less rigorous • No standards for repairs or alterations • No provisions for upgrading non-UL142 to acceptable condition • All in all, however, generally appropriate to level of risk involved
Relevance of SP001-00 to States and EPA • Minnesota • Other states • EPA
Minnesota • SF tanks at small facilities: • Rules require equivalent of periodic but not certified • Rule change would be needed for certified • SF tanks at major facilities: • Permits do not now require inspection of SF tanks • Re-permitting will require SP001-00 starting 2001
Minnesota • Enhancements to SP001-00 to be required: • Walk-around inspection monthly • Periodic records kept for three years, certified report kept for life of tank • Records and reports must documentrepairs needed and made • Repairs recommended must be made unless waived • Certified report must include UT and other data
Minnesota • So far, no facilities seem to be using SP001-00 • Owners waiting for state/federal requirement? • Some consultants now use API 653 for SF tanks • Consultants who are API 653 certified will be in a position to offer lower cost SP001-00 certified inspections
Other States • Wisconsin • Working with STI to offer inspector certification • Pennsylvania • Has its own integrity inspection criteria • Other states?
EPA • Current SPCC requires “periodic integrity testing”, gives examples of visual and N-D shell thickness (UT) testing (112.7(e)(2)(vi)) • SPCC revisions (when final) will be more specific about frequency and technique, and will specifically refer to SP001-00
Issues • Standard has weaknesses • Availability of qualified inspectors • How to get the owner “into the program” • How to get that first certified inspection
Conclusions • On the whole, SP001-00 should prove valuable • States and EPA can jointly have a positive influence on industry standards, e.g. STI, API (new RBI standard), Fertilizer Institute • Would like to see more partnering with industry groups on AST standards, especially with API