nde for high-temperature hydrogen attack (htha): a joint
TRANSCRIPT
NDTMA 2020 Annual Conference
NDE for High-Temperature Hydrogen Attack (HTHA):
A Joint Industry Program (JIP)Success Story
Michael NugentPrincipal EngineerLPI, Inc.NY, NY
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Technical AdvisorSNI
State College, PA
The Urgency for Viable NDT Methodology
In 2010, there was a multi-fatality incident in a refinery that seriously put into question the NDE community’s ability to reliably assess equipment
condition in High Temperature Hydrogen Service.
Through a Joint Industry Project (a consortium of 6-10 Owner Users), the deficiencies were indeed
highlighted, reviewed and a new approach has led to major revisions in the inspection methodologies.
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
AbstractThis restored confidence with NDE inspections and has paved the way for Fitness for Service methodologies to evolve to meet the industry needs.
A brief overview of this 6+ year project
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Hydrogen is crucial in fuel manufacture
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Presentation Outline
• The Bad (HTHA Failure subsequent CSB Alert)
• The Ugly (Pre-2014 State of the Art for NDE Inspection for HTHA
• The Good (JIP HTHA NDE Response and Worldwide Training Programs)
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
The Bad: What is HTHA
• Damage Mechanism well known since the 1930’s (Ammonia Synthesis)
• Function of material alloy content, temperature, partial pressure H2, time, stress and operational upsets
• Temperatures must be above 400 F (the hotter the more extensive the attack)
• Atomic Hydrogen (H+) is necessary, higher the pressure (concentration), the more extensive the attack
• Damage is cumulative over time and does not reverse• Stress (applied or residual) plays a factor
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
The Bad: HTHA
HTHA results from hydrogen service at elevated temperatures and pressures. The hydrogen (H+) reacts with carbides in steel to form methane (CH4) which cannot diffuse through the steel. (Play Graphic)
C
H
CH4
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
It is a Progressive Damage (Play Graphic)
The loss of carbide causes an overall loss in strength. Methane pressure builds up, forming microfissures that may combine to form cracks.
The Bad: HTHA
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
THE UGLY: NDE ROUND ROBIN• 9 Owner-Users Sponsors (Big
Oil to Single Refiner)• Collected 25 samples with
proven damage and no damage
• Evaluate 8 industry vendors on up to 10 different NDT techniques (4-5 “Majors”, 2-3 “Boutique” NDT Service Providers)
• NDT Round began this in Feb 2013 and completed in Sept 2013
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Old API 941 Recommended Methods
Backscatter Techniques
Velocity Ratio
Attenuation
Spectral Analysis Amplitude
Pattern Recognitio
n
Spatial Averaging
Directional Dependen
ce
Frequency Dependen
ce
Conventional Shear
Wave
High Frequency Shear Wave
Angle Beam
Spectral Analysis
Highlyunreliabl
e
Yes: Works but
not for scanning
Broadly works but not
forscannin
g
UnreliableBroadly
works but not reliable
UnreliableBroadly
works but not reliable
Broadly works but
not forscanning
Not reliable Not reliable
Not reliable
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
The Ugly: Multiple Vendors/Techniques
V 1V 2V 3V 4V 5V 6V 7V 8V 9
V 10
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
¼” each Macro etch Both Sides
Macro Name
# of NDT Hits
Macro Damage Y/N/M
Mount #
PF3-A 0 Y Big 3" Mount
PF3-B 0 N Big 3" Mount
PF3-1 1 N-2 3 M PF3-2-1-3 3 N-4 4 N PF3-4-2-5 4 M PF3-5-3-6 3 N
A 12 34 56 B
Each Color represents Different Vendor confirmed “Hit”
Oval and Rectangle represent 2 different Interns “Interoperation” of Location per
Report
THE UGLY: Variable Results/Same Sample
None of Vendor-Called areas had damage. Area A and B (with Star) called “clean” but all had 40% HTHA Attack
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
THE UGLY: SUMMARY
• Over 600 areas of multiple “calls” form multiple vendors and techniques identified
• 150 samples examined under Microscope• 1 positive Confirmation-149 No Damage
It gets worse• 2” through wall crack missed by 5 of 6 vendors
(near Flange hub)• Two “Good” areas by all vendors had 40-50%
attack
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
US Chem Safety Board Recommendation
With no viable NDE Method to insure Integrity, each refinery was looking at replacement costs of $50-150 Million per Hydrogen Unit (some have 2-10 Units)
The Good: Practical approach-what works
• Regrouped with an NDE Training (not Service provider or OEM) and Academic to review what went wrong with trials
• Tried different Modalities and methods on samples from Round Robin
• Review typical damage found and missed• Practiced in shop and took it to use in field-like
conditions on Ex-Service Exchangers
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
The Good: Dissected Exchanger with HTHA
Can 3
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
The Good: NDE on Ex-Service Exchangers
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Extract Damage for Testing and Training
Exchanger TB LW3
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Typical Exam example and report format
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Importance of Technician Training
Soon-to-be API RP 941 guidance regarding state-of-the-art NDE (TOFD, PAUT, FMC/TFM): “These techniques, procedures, and operator proficiency should be
demonstrated on a broad spectrum of HTHA damaged samples (including both damage degree and damage areas, i.e., welds and base metal).
Be aware that individuals receive thorough training, not companiesMake sure the technician working in your refinery received training.
Up to 50% of students in PDI effort for HTHA inspectors may fail the training test in any given class.Students are typically experienced and familiar with the inspection
equipmentThis emphasizes difficulty of HTHA inspections with ultrasonic testing
Performance Demonstration Initiative (PDI) for HTHA
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Some Dated StatisticsTechnician StatisticsTotal number of Techs Examined: 96Number of Initial Pass: 64Number of Initial Failures: 32Number of Retraining Pass: 12
Exam statisticsAcquisition = 3 samplesAnalysis = 6 data filesTotal: 9 elements per examNumber of total exams: 96Total number of elements 864Percentage Passed: 92.5%Percentage Failed: 7.5%
Broadly equal pass/fail between acquisition and analysis
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
SummaryPrerequisite:
All students are expected to be proficient at TOFD and PAUTNot all students were, despite holding respective level 2 certificationTwo students were incapable of performing TOFD despite holding level 2
certificationPrevious HTHA Experience:
Some students have had extensive experience inspecting for HTHAPrevious HTHA experience has not shown to be markedly beneficial
Reasons for failure:Common reasons for failure were falsely calling material inclusions HTHASome students failed from missing HTHA that had coalesced into large
cracks16 students failed data acquisition (this included analysis of their own
data)23 students failed data analysis exam (6 separate data files)
NDTMA 2020 Annual Conference
Golden Nugget Hotel, Las Vegas, NV February 11-13, 2020
Thank you for your participation in the NDTMA 2020 Annual Conference
Michael Nugent [email protected] 212 233 2737C 201 446 0212www.lpiny.com