1. Inadvertent Exchanger Tube
Bundle Extraction
a Safety Critical Mistake
James R. “Chezo” Cesarini, PE
Maintenance Manager
Valero Refining - Texas, LP
Texas City, Texas
james.cesarini@valero.com

2. Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Operational Situation
• September 30, 2005 @ 06:30 AM
• Shift Change @ Gas Oil
Hydrotreater (GOHT) Unit
• Cold Separator Trim Condenser
– E-13-1308
• Plant down from hurricane Rita – in
process of starting up
• Tube leak identified during start up
requiring bundle replacement
• Having difficulty extracting bundle
from shell - 50K LB with extractor
• In addition to bundle extractor,
have added 450 LB steam in the
shell – common practice
• Currently in process of adding
stress relieving coils to shell – also
common practice

3. • 8 ½ hours of steam addition
• Adding additional coils to
expand shell
• Rapid heat ramp to 800 Deg. F.
• Steam escaping from bottom
shell nozzle– Cooling Water Inlet
• Blind on CW Inlet was tightened
to lessen steam loss
• Pressure built in the shell (> 360
psig)
• Shell condensate quickly
became steam
• Steam exit orifice equal or
smaller than entrance orifice
Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Incident Description

4. • Closing the bottom blind (CW
Inlet – 450 LB Steam Inlet)
allowed the following to occur:
– Pressure to build In the shell
– Rapid vaporization of
condensate to steam
(reaching sonic velocity)
– expansion of shell (coupled
with the external heating coils)
• Result
– One Inadvertent Bundle
Launch
• Bundle contacted extractor gear
box and landed 58 feet away
• Extractor gear box traveled 108
feet through sour water pumps
Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Incident Description

5. Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Root Cause of Incident
• Impatience - extended length of
time to extract bundle
• Loss of focus – Deviation of
proven procedure without
thorough review
• Pressure build in shell due to
inadequate venting
• Volumetric expansion of
condensate to steam
• Excessive heat ramp with
external coils (rapid shell
expansion)
• Steam alignment incorrect from
the beginning entering from the
bottom and exiting from the top
• EIL source violation – adding an
energy source to LO/TO item
Steam added from the bottom
+ Blind Flange was later closed
Reduced area of escape for steam +
Condensate build in vessel–no escape
Additional Heat
Source - 800 Deg. F.

6. • More rigorous procedure to
extract bundle is necessary
• Increased communications
necessary when making a
change during a process
• Avoid using a compressible
fluid in all cases if possible
• Adding steam to LO/TO item is
breech of the Energy Isolation
List (EIL)
• Add a pressure indicator to the
system for safety observation
• Additional craft training and
observation regarding steam
line up is warranted
• Have an experienced technician
or engineer review/calculate the
configuration
Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Lessons Learned

7. • Providing additional LO/TO and
EIL training to all refinery
personnel
• Informing all within Valero
Refining system about incident
• Informing petrochemical
community about incident
• Preparing procedure to safely
extract difficult bundles
• Amending refinery Safety and
Health Guideline for LO/TO and
EIL
• Requiring a pressure indicator
with this configuration
Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Counter Measures

8. • Bundle change provided
opportunity to install new
proprietary patented pressure
seal
• Pressure seal allowed
exchanger reassembly without
welding on another diaphragm
• Successful pressure seal
installation paved the way for
future modification on 13 other
exchangers
• Successful pressure seal will
save substantial $$$ for all
future shutdowns
– Time savings
– Easy assembly
– Reliability issue resolved
Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Opportunity Provided (!) – Existing Arrangement

9. • Leak Free Service
• Interest has exploded
– VLO McKee
– VLO Delaware City
– VLO Wilmington
– Eastman TN
– VLO Texas City
• Everyone likes their
own idea!
Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Opportunity Provided (!) – Post Modification

10. • Incident
• EIL violation – adding energy
source to a LO/TO item
• Inadequate venting of steam
during use as a heat source
• Loss of concentration during
heat of battle
• Opportunity
• Opportunities exist even during bad
situations
• Thinking outside the box today will
save $MM for us going forward
• Thinking outside the box can still
be considered coloring within the
lines
Inadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical MistakeInadvertent Exchanger Tube Bundle Extraction … a Safety Critical Mistake
Summary