Overview. MISTRAS Overview

Transcription

1 1 MISTRAS

2 2 Improved RBI Analysis of Above Ground Storage Tanks Through the Use of On Stream Inspections Sam Ternowchek Mistras Group

3 Internal Inspections of Tank Floors is Expensive

4 Inspection Frequency Considerations a) the nature of the product stored; b) the results of visual maintenance checks; c) corrosion allowances and corrosion rates; d) corrosion prevention systems; e) conditions at previous inspections; f) the methods and materials of construction and repair;

5 Inspection Frequency Considerations g) the location of tanks; h) the potential risk of air or water pollution; i) leak detection systems; j) change in operating mode k) jurisdictional requirements; l) changes in service

6 Determine Internal Inspection Interval Interval Based on Fixed Time and/or Corrosion Rate O OR Risk Based Inspection Internal Tank Assessment

7 API 653 Inspection Interval Determined using the corrosion rate procedures Or, using the RBI procedures

8 Comparison Direct Measurements in API 653: Based on the sum of the product side and soil side bottom corrosion rates Traditional approach for determining inspection intervals in API 653 Tends to be a conservative approach because it is based on the sum of corrosion rates Inspection Interval Shorter then Necessary False Sense of Security

9 Comparison RBI Assessment with 10-Year Update Assessments based on API 580/581 as implemented in API 653: Based on direct measurements or conservative-provided estimates of the bottom corrosion rates Tends to be considered realistic estimates because it is based on the maximum corrosion rate of the bottom Provides a More Optimal Inspection Intervals Assessments performed more often

10 API 653 Inspection Interval If an RBI (Risk Based Inspection) assessment has been performed the maximum initial internal interval does not apply to tanks An owner/operator can establish the subsequent internal inspection interval using risk based inspection (RBI) procedures in accordance with API RP 580 and the additional requirements of API 653

11 Factors to Consider in a RBI Assessment The tank design and material of construction Details about the foundation and surrounding area Operational history Inspection history On Stream Inspections Product characteristics Etc.

12 On Stream Tank Inspections API 653 In-Service Inspection Appendix C1.1 Advance NDT Techniques Acoustic Emission to identify active corrosion on tank floor Automated UT for corrosion mapping on tank shell (Liquid to air preferential pitting) Bulk wave UT for corrosion detection in critical zone Pulsed Eddy Current and MWM for CUI

13 ADVANCE NON-INTRUSIVE SOLUTIONS TO TANK INSPECTION

14 What is Acoustic Emission (AE) Passive Listening Technique using Piezo Electric Transducers

15 AE AE Sources from Corrosion AE Sensor Active Corrosion process ACOUSTIC EMISSION Fracture Decohesion of precipitation Metal Dissolution Thick oxide breakdown Hydrogen evolution Corrosion products spalling

16 16

17 Acoustic Sources Detected Sources of interest: Spalling of corrosion products. Leak noise: flow interruption, or turbulence. Extraneous noise to be removed: Roof and structural movement. External and pipe-borne noise. Condensation, particle impacts and valve leakage.

18 Corrosion of Internal Zinc Anodes Internal sacrificial anodes corrode in place on tank floor. Zinc blocks can be large. Oilfield production tanks use sacrificial anodes-very active when coating has failed, until zinc used, then floor corrodes. Emission from active anodes in a 180 foot diameter tank, 6 ft. x 3 ft. in size, (30 in tank, 4/10/16)

19 Recommendations Matrix Overall Grade A B C D E PLD Grade (2) 1 A (2) 1 B C D E Clearly leaking tanks often unable to grade, (should be opened anyway).

20 3-D View of a Bad - E Grade and a Good A Grade

21 FOLLOW UP INTERNAL INSPECTION

22 Relative What is the Reliability: * Follow-up results versus AE-grades, normalised per AE-grade population of 157 tanks (Shell, Dow-Stade, DSM, A B C D E FU 1/2 Minimal damage: no repairs FU 4 Significant damage: major repair/new floor FU 3 Damage: some repairs AE-grade * P.van de Loo/Shell, B.Hermann/Dow, ECNDT 1998

23 Annular Ring UT Inspection

24 Long-Range Automated Ultrasonics (LRUT) Annular Ring Test for Tanks. Gives condition information about critical annular area. Test with Bulk Wave Ultrasonic In-service test. Manual or semi automatic Targets 500m m

25 LRUT Annular Ring Test LRUT Inspects critical area, ~20-30 cm. Automated UT, Plan image. Detects first edge of corrosion 40 m/day. Indicative, not quantitative. SHELL: PLAN VIEW IMAGE SHOWING SEVERE UNDERSIDE CORROSION

26 Tank Shell Surveys

27 CUI Corrosion Under Insulation MR-MWM-Array Inspection of Corrosion Through Protective Barriers JENTEK Sensors, Inc Clematis Avenue, Waltham, MA Slide 27 Copyright 2014 JENTEK Sensors All Rights Reserved.

28 CUI - Technology Summary / Thickness Lift-Off Imaginary (Im) 1. Sensors: MR-MWM -Arrays 2. Next Generation 8200 GridStation Paradigm shift in sensor design (first priority is predictable response based on physics-based modeling) Electronics Very low frequencies (deep penetration) High data rates Minimal drift Scan Direction i l/4 3. GridStation Software using Hyperlattices Rapid, autonomous data analysis Performs multivariate inverse method (MIM) using precomputed databases Defect Images Performance Diagnostics Noise Suppression Images Analysis h (lift-off) m (permeability) MWM sensor D (Thickness) Solve Multiple Unknown Problems MIM Real (Re) Slide 28 Copyright 2014 JENTEK Sensors All Rights Reserved.

29 29 An Example Tank Management Program Plant Condition Monitoring Software - PCMS

30 Background PCMS Captures all operating and design information as it relates to facility tankage PCMS evergreens the RBI process per tank circuit, taking into account Operating information Current corrosion rates Historical Inspections On Stream Inspections API 653 Visual Inspections recorded within PCMS Scheduling Flexibility (RBI/Corrosion/Fixed Based Interval)

31 TANK RBI SCREENING PCMS defines tank damage mechanisms per mode PCMS automatically screens which damage mechanisms the tank is susceptible to. PCMS calculates both base and current Probability of Failure

32 TANK RBI SCHEDULING PCMS will notify inspector what damage mechanisms to inspect for PCMS generates an inspection plan per intrusive/extrusive inspection types, and effective techniques to use to detect potential damage mechanisms (customizable) User has option to schedule by fixed /corrosion/rbi based intervals

33 RBI MATRIX Tank circuits are plotted in the RBI Matrix Plotting takes into consideration POF and COF (Probability and Consequence of Failure) Consequence values are configured per facility RBI Matrix is customizable

34 Example - Initial Internal Inspection Interval Original Design life > 10 years 25 years max 20 years max for original High rank Risk Assessment 2012 MISTRAS GROUP, INC. ALL RIGHTS RESERVED. DISSEMINATION, UNAUTHORIZED USE AND/OR DUPLICATION NOT PERMITTED.

35 Extensions Overall Grade A B C D E PLD Grade A (2) 1 B C D E MISTRAS GROUP, INC. ALL RIGHTS RESERVED. DISSEMINATION, UNAUTHORIZED USE AND/OR DUPLICATION NOT PERMITTED.

36 Benefits of RBI Identify tanks which do not require immediate internal inspection and repair Saving MONEY Determine the condition of damaged floors so that a correct priority for internal maintenance may be set Better scope of work when planning tank opening Reduce down time when out of service Do the above with little or no disruption to operations Help prevent tank leakage

37 In Conclusion - RBI Assessments May lengthen or shorten the inspection interval May result in additional focused inspections Allows a company to focus its resources On Stream Inspection Improve the accuracy of RBI

38 QUESTIONS????

39 MUCHAS GRACIAS