Program for Prevention of CUI at a Refinery

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Gordon H. Hart's Presentation at the NACE Bring on the Heat 2013 conference

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Program for Prevention of CUI at a Refinery

  1. 1. Program for CUI Prevention at a Refinery Gordon H. Hart, P.E. Artek Engineering, LLC Bring on the Heat 2013 New Orleans, LA June 6, 2013 1
  2. 2. Project Objectives • Make recommendations to an oil refinery on methods for minimizing occurrences and severity of Corrosion Under Insulation • Maintain as many existing materials, procedures, and practices as practical while reducing CUI • Minimize insulation first cost and life cycle cost • Maximize life of pipe & equipment and of insulation systems • Enhance safety at the refinery 2
  3. 3. Primary Methods • Identify practices that should be continued • Identify practices that should be changed and recommend new practices • Identify practices that should be discontinued • Recommend new practices to minimize water intrusion into thermal insulation • Premise: there is no single “silver bullet” solution to reducing CUI 3
  4. 4. References 1. NACE Standard Practice 0198-2010: “Control of Corrosion Under Thermal Insulation and Fireproofing Materials—A Systems Approach” 2. API Recommended Practice 583, 2nd Draft (Sept, 2012), “Corrosion Under Insulation and Fireproofing”. 3. Several articles from journals 4. ASTM material specifications 4
  5. 5. Background • Refinery site for over 100 years • Two units constructed in late ‘60’s, early ‘70’s using asbestos-reinforced calcium silicate insulation with aluminum jacket (with much still in place) • Several other units constructed since then mostly using asbestos-free cal-sil insulation • Use of cellular glass insulation, for pipes with operating temps < 450°F, started in 2010 • Removable/Reusable blankets used on many heat exchanger heads & valve bodies but not on flanges • Use of protective coatings has started recently • Steam tracing is being replaced by electric tracing 5
  6. 6. Much of the insulation in good condition 6
  7. 7. Much of the insulation in good condition 7
  8. 8. What are some of the problems? • Pipe thinning due to CUI at certain locations (i.e., a pipe is only as strong as its weakest point) • Limited budget for X-ray examination of pipes and only smaller pipes can be done • Limited budget for insulation maintenance and replacement • Most older pipes & equipment were never coated for protection for CUI • Some pipes were insulated that may not need it 8
  9. 9. What are we trying to avoid? 9
  10. 10. Problem # 1: Insulation System in Poor Condition or missing 10
  11. 11. Solution to Problem # 1: Replace with specified materials 11
  12. 12. Problem # 2: Use of low compressive strength insulation on many fittings 12
  13. 13. Solution to Problem # 2: use high compressive strength insulation at fittings 13 Use of low CS insulation at elbows, on left, and high CS insulation at elbows, on right
  14. 14. # 3: Placement of insulation too close to flanges 14
  15. 15. Solution to Problem # 4: leave clearance 15
  16. 16. Problem # 4: Gaps & tears in the metal jacketing 16
  17. 17. Solution to Problem # 4: Replace or use metalized PSA tape to repair 17
  18. 18. Problem # 5: Missing metal jacketing Solution to # 5: Replace missing jacketing! 18
  19. 19. Problem # 6: Shifted & exposed insulation 19
  20. 20. Solution to Problem # 6: Repair with specified insulation materials 20
  21. 21. Problem # 7: Use of temporary wrap insulation as a fast insulation fix 21
  22. 22. Solution to Problem # 7 • Replace with either specified material or with removable / reusable wrap insulation that has silicone coated fabric 22
  23. 23. Problem # 8: Deteriorated R/R blankets 23
  24. 24. Solution to Problem # 8 – Replace with new, good quality R/R blankets 24
  25. 25. Problem # 9: Pipe support design allows water intrusion 25
  26. 26. One Solution to Problem # 9: use insulated pipe supports 26
  27. 27. Another Solution to Problem # 9: install splash shields over pipe supports 27
  28. 28. Problem # 10: Use of unjacketed, water absorbent insulation 28
  29. 29. Solution to Problem # 10: only jacketed insulation or use unjacketed insulation that is not water absorbent 29
  30. 30. Problem # 11: Complex surfaces that allow lots of water intrusion 30
  31. 31. Solution to Problem # 11: Either use R/R blankets plus high temp rubber insulation or do not insulate 31
  32. 32. Problem # 12: Broken jacket seals 32
  33. 33. Solution to Problem # 12: Either reseal jacket or use metalized PSA tape 33
  34. 34. General Recommendation # 1: Use calcium silicate for temps ≥ 350°F 34 Features & Benefits: (1) very high, 100 psi compressive strength, (2) non- combustible (3) chemically inhibited and hence does not contribute to corrosion of steel when wet (4) maintains high strength up to 1200°F (5) long history of successful use at temps ≥ 350°F
  35. 35. General Recommendation # 2: Use cellular glass for temps < 350°F 35 Features & Benefits: (1) does not absorb water (2) fairly high, 60 psi compressive strength, (3) non-combustible (4) does not contribute to corrosion of steel
  36. 36. General Recommendation # 3: Continue using aluminum jacket w/ polysurlyn moisture barrier 36 Features & Benefits: (1) resistant to corrosion from HCs (2) inside moisture barrier is resistant to galvanic & pitting corrosion (3) when sealed, keeps out water
  37. 37. General Recommendation # 4: continue using R/R blankets where accessibility is needed 37 Features & Benefits: (1) removable & reusable insulation allows for mechanical maintenance (2) insulates effectively (3) does not absorb & hold water against steel surfaces (4) durable materials
  38. 38. Other General Recommendations – either replace with specified materials or 5. Seal damaged aluminum jacket with caulk (prevents water intrusion) 6. Seal lap joints at 90° & gaps with metalized PSA tape or replace (prevents water intrusion) 7. Use protective coatings where operating temperature allows (protects steel from corrosion) 8. Use temporary wrap insulation that is suitable for operating conditions (does not hold water against steel surfaces and meets temperature requirements) 38
  39. 39. Thank you for your attention • Are there any questions? 39

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