Program for Prevention of CUI at a Refinery

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

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

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

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

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

Much of the insulation in good condition
6

Much of the insulation in good condition
7

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

What are we trying to avoid?
9

Problem # 1: Insulation System
in Poor Condition or missing
10

Solution to Problem # 1:
Replace with specified materials
11

Problem # 2: Use of low compressive
strength insulation on many fittings
12

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

# 3: Placement of insulation
too close to flanges
14

Solution to Problem # 4: leave clearance
15

Problem # 4: Gaps & tears
in the metal jacketing
16

Solution to Problem # 4: Replace
or use metalized PSA tape to repair
17

Problem # 5: Missing metal jacketing
Solution to # 5: Replace missing jacketing!
18

Problem # 6: Shifted &
exposed insulation
19

Solution to Problem # 6: Repair with
specified insulation materials
20

Problem # 7: Use of temporary wrap
insulation as a fast insulation fix
21

Solution to Problem # 7
• Replace with either specified material or with
removable / reusable wrap insulation that has
silicone coated fabric
22

Problem # 8: Deteriorated R/R blankets
23

Solution to Problem # 8 – Replace with
new, good quality R/R blankets
24

Problem # 9: Pipe support design
allows water intrusion
25

One Solution to Problem # 9:
use insulated pipe supports
26

Another Solution to Problem # 9:
install splash shields over pipe supports
27

Problem # 10: Use of unjacketed,
water absorbent insulation
28

Solution to Problem # 10: only jacketed
insulation or use unjacketed insulation that
is not water absorbent
29

Problem # 11: Complex surfaces that
allow lots of water intrusion
30

Solution to Problem # 11: Either use R/R
blankets plus high temp rubber insulation
or do not insulate
31

Problem # 12: Broken jacket seals
32

Solution to Problem # 12: Either reseal
jacket or use metalized PSA tape
33

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

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

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

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

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

Thank you for your attention
• Are there any questions?
39

Program for Prevention of CUI at a Refinery

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