HIGH ENERGY PIPING INSPECTION PROGRAM

Transcription

1 HIGH ENERGY PIPING INSPECTION PROGRAM JOEL LUNDQUIST STRESS ANALYSIS SECTION B&V ENERGY

2 AGENDA About Black & Veatch Introduction Power Piping Code Initial Baseline Assessment Evaluation by Non-Destructive Examination Computerized Stress Analysis Assessment Report and Recommendations Concluding Remarks Questions 2

3 ABOUT BLACK & VEATCH 3 3

4 BLACK & VEATCH CORPORATION IS A LEADING GLOBAL ENGINEERING, CONSULTING AND CONSTRUCTION COMPANY Founded in 1915 Global workforce of more than 9,000 More than 100 offices worldwide Projects in more than 100 countries on 6 continents $2.6 billion in annual revenues in 2011 Ranked on Forbes America s Largest Private Companies listing One of the largest majority employee-owned companies in the U.S. Reputation of integrity, competence and highest safety standards 4

5 BLACK & VEATCH CONSULTING PVT LTD (PUNE) Business in India from 1977; office established in 2004 Business Areas Energy and Telecom Workforce More than 150 professionals Energy Departments Engineering (Mechanical, Electrical & Controls, Civil & Structural), Project Control, Proposals, Procurement, Quality, Human Resources, and Administrative Office with project execution capabilities Equipped with commercial and B&V proprietary engineering tools 5

6 INTRODUCTION 6 6

7 INTRODUCTION Piping failures can result in equipment damage, costly repair, unit outages and injury to plant personnel Pipe supports functioning improperly can result in sagging pipe, undue piping stresses and increased loading on equipment connections A High Energy Piping (HEP) inspection program will assess and monitor condition of piping and supports to identify issues early 7

8 INTRODUCTION Black & Veatch (B&V) has assisted many utilities in developing and implementing HEP inspection programs for fossilfueled power generating facilities in North and South America Discuss B&V s typical approach for initial assessment, development and implementation based upon ASME B31.1 Power Piping Code, industry practice and past experience 8

9 POWER PIPING CODE 9 9

10 POWER PIPING CODE Chapter VII of ASME B31.1 includes requirements for establishing program to assess and document condition of HEP or covered piping systems to ensure safe unit operation Code defines covered piping systems (CPS) Systems generally include NPS 4 and larger of main steam, hot reheat steam, cold reheat steam and boiler feedwater Other piping systems may be included due to past operating history or damaging transient events 10

11 POWER PIPING CODE Non-mandatory Appendix V of ASME B31.1 provides further recommendations for minimum requirements for establishing program Requirements and recommendations of ASME B31.1 are framework that B&V uses to perform condition assessments and develop HEP programs for clients 11

12 INITIAL BASELINE ASSESSMENT 12

13 OPERATING HISTORY Operating hours and modes of operation Typical operating temperatures, number and frequency of significant temperature excursions Past dynamic events Discussion of inspection program or past inspections Past non-destructive examination (NDE) Planned outage schedule 13

14 DOCUMENTATION REVIEW Past hanger inspection data Piping and support drawings for HEP Documentation for original piping material specifications, diameter, wall thickness, design temp. and pressure Past inspection or NDE reports Steam turbine outline and stop valve drawings, allowable forces and moments Boiler drawings including thermal movements, allowable forces and moments Records for past piping or support modifications 14

15 INSPECTION OF PIPING AND SUPPORTS Observe and record travel position for springs in hot and cold position Pipe support locations and type match drawings Loose, missing, damaged, or broken hardware Damaged or corroded hardware 15

16 INSPECTION OF PIPING AND SUPPORTS Evidence of damaging dynamic or transient events Damaged or modified insulation Observe steam lines for proper slope towards drain pots Proper thread engagement Proper gaps for pipe restraints Interference of piping or supports with adjacent pipe, steel, or equipment Record pipe temperature at time of inspection Inspections recommended to be performed on annual basis as minimum 16

17 CONSTANT SPRING SUPPORTS Observe and record travel position in the hot and cold position Compare against original design and past inspections 17

18 VARIABLE SPRING SUPPORTS Observe and record travel position in the hot and cold position Compare against original design and past inspections 18

19 RIGID HANGERS Confirm adequate thread engagement, signs of clamp damage or bent rod 19

20 HYDRAULIC SNUBBERS Inspect for evidence of free thermal expansion, damage, signs of hydraulic fluid leakage and fluid level 20

21 RIGID STRUT Inspect for loose hardware or signs of damage 21

22 LIMIT STOP Ensure proper gaps in the cold and hot position 22

23 EVALUATION BY NON-DESTRUCTIVE EXAMINATION (NDE) 23

24 EVALUATION BY NDE NDE recommended at key locations to identify defects and determine remaining life for piping Key locations determined by areas of concern during visual inspections, results of past NDE, experience, and industry practice Locations often categorized by priority to accommodate outage timing or duration Various types may be employed 24

25 HIGHER PRIORITY Turbine inlet, stop valve inlet, stop valve outlet, boiler inlet, and boiler outlet girth welds Girth welds for piping wyes Crotch of piping wyes Seam for seam welded piping Welded lugs and stanchions for highly loaded pipe supports Key pipe segments and bends for flow erosion thinning Confirmation if seam weld is present Locations visibly damaged due to dynamic or transient event 25

26 MEDIUM PRIORITY Welded pipe lugs and stanchions for less highly loaded pipe supports Inspection of branch connection welds 26

27 INSPECTION FREQUENCY Generally five years or 35,000 operating hours between first and second inspection of particular location Interval between second and the next test is determined by comparison of the first and second test Qualified NDE contractor can also provide recommendations regarding frequency of inspection 27

28 TYPES OF NDE Visual Examination For visible surface defects Positive Material Identification Confirm piping material Pi Tape Diameter Measurement Measure outside diameter Wet Fluorescent Magnetic Particle Identify surface defects in weld and base metal Ultrasonic Wall Thickness Measurement Measure wall thickness for use in stress analysis and identify wall thinning 28

29 TYPES OF NDE Linear Phased Array Ultrasonic inspection method for defect detection in pipe welds Time of Flight Diffraction Another ultrasonic method for defect detection in pipe welds Replication Inspect microstructure for creep damage Acid Etch Surface examination for presence of seam weld Acoustic Emissions Monitoring 29

30 NDE CONTRACTOR NDE shall be performed by qualified contractor NDE shall be performed in accordance with written procedures prepared by the contractor and approved by certified inspector Microstructures from replications shall be interpreted by metallurgist experienced in evaluating microstructures for creep damage Contractor shall document results in detailed report that provides summary of testing completed, results, photographs, locations tested, recommendations for future inspections, and exact location of rejectable indications 30

31 COMPUTERIZED STRESS ANALYSIS 31

32 COMPUTERIZED STRESS ANALYSIS Piping and hanger inspections may reveal issues which require evaluation by stress analysis 32

33 COMPUTERIZED STRESS ANALYSIS As-Designed Analysis Based on original design parameters to compare against original analysis. Baseline for other analyses As-Built Analysis Include any discrepancies between original design documents and inspections As-Existing Analysis As observed during hot inspections As-Modified Analysis Include recommended support additions, replacement, or modification 33

34 ASSESSMENT REPORT AND RECOMMENDATIONS 34

35 REPORT AND RECOMMENDATIONS Following personnel discussions, documentation review, and support inspections, B&V prepares a report which summarizes evaluation and provides recommendations Summarizes and identifies areas of concern regarding past operating history and documentation review Results and findings of piping and support inspections, including tables documenting spring hanger position and support observations Recommendations for NDE, including, inspection locations marked on drawings and spreadsheet indicating inspection methods at each location 35

36 REPORT AND RECOMMENDATIONS Recommendations for hanger adjustments, repairs or replacement Load testing of certain springs may be recommended Recommendations for follow-up inspections following hanger repair or replacement Computerized stress analysis may be recommended to determine root cause and corrective actions for piping or support performance issues observed 36

37 CONCLUDING REMARKS 37

38 CONCLUDING REMARKS Development and implementation of plan to assess and monitor condition of HEP and supports is crucial Initial baseline assessment Plan for future inspections Will aid in identifying issues early to avoid costly repairs, equipment damage, unscheduled outages, injury to plant personnel 38

39 QUESTIONS? PLEASE VISIT US AT: BOOTH # 1139, HALL 11 39

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