Presented By: CFM/VR-TESCO, LLC Scott Smith – SVP & General Manager Roy Button – Welding Engineer & Specialty Welding (WDI) Division Manager Our Presentation Focus WHO ARE WE? Continental Field Machining (CFM) formed a valve repair division in 1986 known as “VR-TESCO”. CFM/VR-TESCO is highly focused on disassembly, inspection, repair, and reassembly of valves throughout the Power Generation Sector. Specialized welding and machining equipment has been developed to effectively complete difficult inline valve repairs. Personnel are given extensive training to perform these activities. 1 Our Presentation Focus Our presentation focus is on ASME Section 1 and B31.1 Code valve repairs performed within the past (2) two years. In this timeframe, CFM/VR-TESCO has performed major welding and machining repairs on (46) forty-six plus ASME Code large bore valves. The valve sizes have ranged between 12” to 24”. Valves from all the major OEM’s have been included in these repairs. 2 Our Presentation Focus (21) twenty-one of these valves are Code Boundary valves, hence repairs are performed following guidelines of ASME Section I and National Board Inspection Code and Jurisdictional requirements. (25) twenty-five plus valves were part of the Boiler external piping, hence repairs are performed following guidelines of ASME B31.1. 3 Original Manufacture of Valves Valves manufactured for use in Power Generation are produced under the American National Standards as outlined in ASME B16.34. This standard applies to new construction and covers pressure-temperature ratings, dimensions, tolerances, materials, NDE requirements, testing, marking for cast, forged and fabricated valves with flanged, threaded or welding ends. 4 Original Manufacture of Valves It is the manufacturer’s responsibility to provide the purchaser with documentation that details his program compliance in the manufacturing of the products. Requirements for manufacturing may be less stringent than those required for repair of the product. Listed are acceptance NDE criteria for new valves manufactured. 5 ASME B16.34 Acceptance Criteria B16.34 - 11-2 Acceptance Standards for Magnetic Particle Examination (MT) 11-2.1 Castings – Maximum acceptable indications are as follows : a. Linear indications (1) 0.3” long for materials up to 0.5” thick. (2) 0.5” long for material 0.5” to 1.0” thick. (3) 0.7” long for material over 1.0” thick. For linear indications, the indications must be separated by a distance greater than the length of an acceptable indication. A linear is one with length in excess of 3 times the width. B16.34 - 11-2 Acceptance Standards for Magnetic Particle Examination (MT) 11-2.2 Forgings and Rolled or Wrought Material – Maximum acceptable indications are as follows: a. Linear indications (1) 0.2” long for materials up to 0.5” thick. (2) 0.4” long for materials over 0.5” – 1.0” thick. (3) .06” long for materials over 1.0” thick. For linear indications, the indications must be separated by a distance greater than the length of an acceptable indication. A linear indication is one with length in excess of 3 times the width. 6 ASME B16.34 Acceptance Criteria B16.34 - 11-2 Acceptance Standards for Magnetic Particle Examination (MT) 11-2.1 Castings – Continued b. Rounded Indications (1) 0.3” diameter for materials up to 0.5” thick. (2) 0.5” diameter for materials over 0.5” thick. Four or more rounded indications in a line separated by 0.06” or less edge to edge are unacceptable. Rounded indications are those that are not defined as linear indications. B16.34 - 11-2 Acceptance Standards for Magnetic Particle Examination (MT) 11-2.2 Forgings and Rolled or Wrought Material – Continued b. Rounded Indications (1) 0.2” diameter for materials up to 0.5” thick. (2) 0.3” diameter for materials over 0.5” thick. Four or more rounded indications in a line Separated by a 0.06” or less edge to edge are Unacceptable. Rounded indications are those that are not defined as linear indications. 7 ASME B16.34 Acceptance Criteria B16.34 - 111-2 Acceptance Standards for Liquid Penetrant Examination (PT) 111-2.1 Castings – Maximum acceptable indications are as follows: a. Linear Indications (1) 0.3” long for materials up to 0.5” thick. (2) 0.5” long for materials over 0.5” to 1.0” thick. (3) 0.7” long for materials 1.0” thick. For linear indications, the indications must be separated by a distance greater than the length of an acceptable indication. A linear indication is one with length in excess of 3 times the width. B16.34 - 111-2 Acceptance Standards for Liquid Penetrant Examination (PT) 111-2.2 Forgings and Rolled or Wrought Material - Maximum acceptable indications are as follows: a. Linear Indications (1) 0.2” long for materials up to 0.5” thick or less. (2) 0.4” long for materials over 0.5” to 1.0” thick. (3) 0.6” long for materials over 1.0” thick. For linear indications, the indications must be separated by a distance greater than the Length of an acceptable indication. A linear indications is one with length in excess of 3 times the width. 8 ASME B16.34 Acceptance Criteria B16.34 - 111-2 Acceptance Standards for Liquid Penetrant Examination (PT) 111-2.1 Castings – Continued b. Rounded Indications (1) 0.3” diameter for materials up to 0.5” thick. (2) 0.5” diameter for materials over 0.5” thick. Four or more rounded indications in line separated by 0.06” or less edge to edge are unacceptable. Rounded indications are those that are not defined as linear indications. B16.34 - 111-2 Acceptance Standards for Liquid Penetrant Examination (PT) 111-2.2 Forgings and Rolled or Wrought Material - Continued Rounded Indications (1) 0.2” diameter for materials up to 0.5” thick. (2) 0.3” diameter for materials over 0.5” thick. Four or more rounded indications in a line separated by 0.06” or less edge to edge are unacceptable. Rounded indications are those that are not defined as linear indications. b. 9 ASME Section I Repairs Repair requirements of a valve are usually confined to the location of the valve in the boiler piping system of the power plant. If the valve to be repaired is located in the piping system which is considered part of the boiler proper or part of the external boiler piping it is declared to be inside the Boiler Code Boundary. Preamble to ASME Section I paragraphs 4, 5 & 7 provide the detailed information defining Code Boundary’s. Repairs to piping and valves within the Code Boundary are repaired using the requirements provided in ASME Section I, National Board Inspection Code (NBIC) and the jurisdiction. 10 ASME Section I Repairs To repair Section I Items a Quality Program & NBIC “R” Stamp certification is required. 11 Section I Valve Repairs CFM/VR-TESCO, LLC performed (21) twenty-one “R” Stamp repairs in 2010-2012. Most of the repairs can be segregated in to 3 groups. 1. Valves requiring a seat or seats replaced. 2. Removal and rewelding of integral valve seats. 3. Repairs of cracks in the valve body or on guide ribs or disc guides. Of the (21) twenty-one valves repaired (10) ten valves required replacement of seat rings. 12 Section I Valve Repairs All (10) valve bodies were SA217-C12A material. (10) Seats had cracks in partial penetration welds of seat to body. Many of these welds had full 360o cracks. (6) Seats had Hardface material missing from the seat face. (1) Valve had 316 SS seats that were cracked 360o and were replaced with A182-F91 material seats. (4) Valves had seats that were manufactured from A355-P22 (P5A) material and they were replaced like for like. 13 Section I Valve Repairs SEAT RING REPLACEMENT All seat ring replacements were completed utilizing the following guidelines: Minimum preheat 400oF. Welding process machine GTAW. WPS – 15E MN/GTAW-HT. .035” dia wire – ER90S-B9. Mn & Ni chemistry < 1.0. PWHT @ 1375oF – 2 hours soak time. 14 Section I Valve Repairs Thermocouples and ceramic pads on ID seat area. Final NDE (PT) & (VT). 15 Section I Valve Repairs INTEGRAL SEAT REPAIR CFM/VR-TESCO, LLC repaired integral seats in (11) Eleven valves from 2010 – 2012. Base metal of valve bodies were: (2) A217-WC6 (9) A217-C12A All (11) valves had cracks in the seat area Hardface going in to the base metal. 16 Section I Valve Repairs (4) Four valves had major cracks in the upper and lower 6oclock rib @ rib to body interface. (10) Ten valves had indications in the Stellite Hardfacing on the guide ribs. This required removal of the Stellite and undercutting of the base metal. The repair required rewelding of the base metal and Hardfacing. 17 Section I Valve Repairs INTEGRAL SEAT REPAIRS CFM/VR-TESCO, LLC utilized the following guidelines for Integral Seat Repairs. 1. All defects removed after removal of Stellite hard facing material and approximately .080” of base metal. 2. NDE (PT) inspection of all repair areas. 3. Sketch and dimensioning of all repair areas. 18 Section I Valve Repairs 4. Preheat valve to 400oF minimum. NOTE: 300oF for P4 material. 5. Weld excavated repair areas and Hardface under cut areas with Er90S-B9. NOTE: Er80S-B2 for P4 material. 6. Base metal area profiled and NDE with dry (MT) on P15E material. Base material is kept at 100oF minimum. No moisture allowed on as welded P15E materials. NOTE: PT or wet (MT) allowed on all other low alloy materials. 19 Section I Valve Repairs 7. Preheat back to 400oF. NOTE: 300oF for P-4 base materials. 8. Apply a minimum of (2) layers of Stellite 21. 9. Cool valve to below 175oF and visually inspect the welds. 10. PWHT minimum hold 2 hours @ 1375oF per heat treat traveler. NOTE: PWHT temp 1250oF for P-4 material. 20 Section I Valve Repairs 11. Profile the seat and ribs to OEM specifications. 12. Final NDE, PT to ASME Section 1, VT to ASME B31.1 13. AI review of the weld data package and issuance of R-1 Form and data plate as required. 21 ASME B31.1 Valve Repairs CFM/VR-TESCO, LLC repaired (25) plus valves per ASME B31.1 requirements in 2010-2012. The majority of the valves were parallel slide gate valves. (22) Valves required seat replacements. ASME B31.1 covers the external boiler piping as defined for power boilers, high temperature, high pressure boilers in which steam or vapor is generated at a pressure of more than 15psig and high temperature water is generated at pressure exceeding 160psig and/or temperature of 250oF. 22 ASME B31.1 Valve Repairs All welding or brazing of pipes or items shall be performed by manufacturers or contractors who perform repairs holding stamps for symbols shown in Fig. PG-105.1 thru PG-105.3 of ASME Section I of the ASME Boiler and Pressure Vessel Code. (B31.1 Chapter 1 100.1.2). The installer of external boiler piping joined by welding or brazing is required to have a Quality Control system meeting, requirements of Mandatory Appendix J of the ASME B31.1 Code. 23 ASME B31.1 Valve Repairs For repairs of valves controlled by the requirements of B31.1 the following are required to be documented. 1. Removal of defect or reduce to acceptable size as outlined in Chapter V 127.4.11. 2. NDE of the defect area by Magnetic Particle (MT) or Liquid Penetrant (PT) examination. NDE inspection acceptance criteria per Chapter V – 136.4.3 for (MT) & 136.4.4 for (PT). 24 ASME B31.1 Valve Repairs 3. Preheat of the base material as required in Chapter V-131 “Welding Preheat”. 4. Welding shall be performed by use of PQR’s, WPS’s & WPQ’s as outlined in Chapter V-127.5. 5. PWHT of the repair as required by Chapter V-132 “PWHT Requirements”. 6. Final NDE of the repair as required in Chapter V-136.4 “Examination methods 25 ASME B31.1 Valve Repairs 6. for Welds & Repairs”. ASME B31.1 Chapter V. a. Visual Examination (VT) – 136.4.2 b. Magnetic Particle Examination (MT) – 136.4.3 c. Liquid Penetrant Examination (PT) – 136.4.4 26 ASME B31.1 Valve Repairs All examinations to be performed by technicians certified to perform each nondestructive examination per ASME B31.1 Chapter V – 136.3.2 “Qualifications of NDE personnel”. 27 REPAIRS – ASME SECTION 1 & B31.1 REPAIR 360O CRACKED SEAL WELD SEAT RING FIGURE - 1 REPAIR 360o CRACKED SEAL WELD SEAT RING FIGURE - 2 28 REPAIRS – ASME SECTION 1 & B31.1 REPAIR SEAL WELDING OF SEAT RING IN GATE VALVE FIGURE - 3 THERMOCOUPLE PLACEMENT FOR PRE-HEAT REPAIR SEAL WELDED SEAT RING IN GATE VALVE FIGURE - 4 29 REPAIRS – ASME SECTION 1 & B31.1 REPAIR 6 O’CLOCK GUIDE RIB CRACKING @ INTREGAL SEAT INTERFACE AND CRACKING 360 DEG. AROUND RIB FIGURE - 5 FIGURE - 6 30 REPAIRS – ASME SECTION 1 & B31.1 REPAIR CRACKING IN INTREGAL SEAT AND GUIDE RIBS IN GLOBE VALVES FIGURE - 8 FIGURE -7 CRACKS IN INTERGAL SEAT CRACKS IN INTREGAL SEAT CRACKS IN GUIDE RIB CRACKS IN GUIDE RIBS 31 REPAIRS – ASME SECTION 1 & B31.1 REPAIR LAMINATION IN GUIDE RIBS FIGURE - 9 LAMINATION IN GUIDE RIB FIGURE - 10 LAMINATION GUIDE RIB PIECES 32 REPAIRS – ASME SECTION 1 & B31.1 REPAIR WELDING INTREGAL SEAT FIGURE - 11 GTAW MACHINE WELD OF INTREGAL SEAT 33 REPAIRS – ASME SECTION 1 & B31.1 REPAIR COMPLETED SEAT RING PARTIAL PENETRATION WELD FIGURE - 12 34 Recipe for Success Successful repair of valves and valve components are a Hallmark of CFM/VR-TESCO, LLC’s years of service. It Takes a lot more than just welding and machining skills to repair today’s valve deficiencies. It starts with gathering all the information available about the valve to be repaired. All the valve component information from the OEM when the valve was 1st purchased. 35 Recipe for Success The customer must supply the following information to allow for the completion of work travelers and R-1 data form if required. Unit Number Boiler Manufacturer Mfg Serial Number National Board Number Jurisdiction Number Year Built 36 Recipe for Success Original Code of Construction System and location of valve being worked Valve Drawing Valve Identification Valve Year of Manufacture 37 Recipe for Success Once all the pertinent information is gathered QA and The Welding Department start the planning process: Initiate work traveler and weld data sheets. Identify WPS’s and Welder Performance Qualifications. Create PWHT Traveler. Identify NDE requirements and notify NDE subcontractor. 38 Recipe for Success Issue filler material and supporting documentation MTR/CMTR’s. Notify Authorized Inspector (If required). Present Data Package to Project Manager for review. 39 Recipe for Success CFM/VR-TESCO, LLC has specialized machining and Welding equipment that is required to repair the different types of valve repairs. Equipment is staged and inspected before shipping to each project. Personnel training on specialized equipment and valve repairs. 40 Recipe for Success The recipe for success may seem simple, but care must be taken on each step to insure the “best possible” results for each valve repair. CFM/VR-TESCO, LLC working with OEM’s and our Customers have been “Teaming Together for Success” for over 26 years. 41 Recipe for Success 42