船舶系统ISE咨询号码。011-87主要推进锅炉（非核）降压管架焊接接头Navsses费城PA MSG 132100Z 5月87日参考：A.IL-STD-22，联合P-3，图3 1.总结：管裂纹的潜在问题是提出了。识别受影响的船舶。检验要求和纠正行动颁布。结束摘要。2. USS Vancouver（LPD-2），USS LASALLE（AGF-3），USS RALEIGH（LPD-1），可能是美国火星（AFS-1）在凹口上经历了脱绒管的周向开裂，由管末端制备导致接受背圈。裂缝的驱动机构已被确定为腐蚀疲劳。最初存在问题限于从背圈制备到管内直径的非锥形过渡。 HOWEVER, THROUGH WALL CRACKS HAVE ALSO OCCURRED IN CONFIGURATIONS SHOWING A 45 DEGREE (ONE TO ONE TAPER) TRANSITION. 3. REFERENCE A SHOWS CONFIGURATION FOR BUTT WELDED JOINTS INCOR- PORATING PERMANENT BACKING RINGS. THIS JOINT REQUIRES A FOUR TO ONE TAPER (APPROXIMATELY 14 DEGREES) AND A 1/16 INCH RADIUS AT THE TRANSITION FROM THE BACKING RING RECESS TO THE TUBE INSIDE DIAMETER. 4. A SURVEY OF BOILER DRAWINGS HAS BEEN CONDUCTED BY NAVSSES. SHIPS WITH DRAWINGS INDICATING DOWNCOMER TUBE BUTT WELDS NOT CONFORMING TO REFERENCE A ARE AS FOLLOWS: NUMBER OF TAPER SHIPS BOILERS MANUFACTURER (RATIO OR DEGREE) AD 41, 42 8 CE 18 DEGREES 43, 44 AFS 1 21 B AND W (NOTE 1) THROUGH 7 AOE 4 4 B AND W 30 DEGREES AO 177, 178 10 CE 18 DEGREES 179, 180, 186 CV 60, 61 16 B AND W (NOTE 1) CV 62 8 B AND W (NOTE 2) CV 63, 64 16 FW 30 DEGREES CV 66 8 FW 25 DEGREES DD 946 4 B AND W (NOTE 1) DDG 2, 3, 7, 8, 32 B AND W (NOTE 1) 10, 11, 12, 13 DDG 20, 21, 22 12 B AND W (NOTE 1) DDG 37, 38, 39 12 FW 30 DEGREES FF 1052, 1053, 68 CE 3/1 1054, 1055, 1058, 1060, 1062, 1064, 1066, 1067, 1070, 1071, 1074, 1076, 1078 THROUGH 1097 LHA 1 THROUGH 5 10 CE 3/1 LHD 1 THROUGH 5 10 CE 3/1 LKA 113 THROUGH 10 CE 3/1 117 LPD 1 THROUGH 6 12 B AND W (NOTE 3) LPH 12 2 CE 3/1 LSD 36 2 CE 3/1 NOTE 1: TAPER NOT DIMENSIONED ON DRAWINGS. NOTE 2: TAPER NOT DIMENSIONED ON DRAWINGS. SHIP IS CURRENTLY IN SHIP'S LIFE EXTENSION PROGRAM (SLEP). ACTION ALREADY IDENTIFIED. NOTE 3: DRAWINGS SHOW NO TAPER. ACTUAL SHIPBOARD CONFIGURATIONS HAVE VARIABLE TAPERS. THROUGH THE WALL CRACK WAS PRESENT ON 45 DEGREE (ONE TO ONE) TAPER. 5. NAVSSES RECOMMENDS THAT BOILER DOWNCOMERS OF SHIPS LISTED IN PARAGRAPH 4 ABOVE BE INSPECTED AT NEXT ROUTINE 18 MONTH WATERSIDE INSPECTION BY A CURRENTLY CERTIFIED STEAM GENERATING PLANT INSPECTOR (SGPI). IF NEXT WATERSIDE OPENING IS DURING A SCHEDULED MAINTENANCE CYCLE, NAVSSES BOILER INSPECTORS WILL EVALUATE THESE DOWNCOMER JOINTS. 6. INSPECTION RESULTS ARE TO BE DOCUMENTED IN BOILER INFORMATION AND REPAIR MANAGEMENT INFORMATION SYSTEM (BIRMIS). POSITIVE AND NEGATIVE RESULTS SHOULD BE INCLUDED. IF INSPECTION DOES NOT COINCIDE WITH SCHEDULED ROUTINE BOILER INSPECTION, ENTER AS A SPECIAL INSPEC- TION. REQUEST NAVSEA AND NAVSSES BE INFORMED BY MESSAGE OR SPEED- LETTER WHEN EACH INSPECTION IS COMPLETED AND RESULTS ARE RECORDED IN BIRMIS. 7. CORRECTIVE ACTIONS SHOULD BE PURSUED AS FOLLOWS: A. IF CRACKS ARE FOUND, THEY MUST BE GROUND OUT AND SATISFAC- TORY NDT CONDUCTED. IF DEPTH OF GRIND OUT REDUCES REMAINING WALL BELOW 2/3, CONTACT NAVSSES FOR DETAILED REPAIR GUIDANCE. TAPER IN CRACKED TUBES AND ALL OTHER SIMILAR TUBES OF THAT BOILER ARE TO BE GROUND TO FOUR TO ONE TAPER REQUIREMENT OF REFERENCE A. RESTORA- TION OF TAPER IN ACCESSIBLE HEADER DOWNCOMERS SHOULD BE ADDRESSED ON A SHIP BY SHIP BASIS. B. IF NO CRACKING IS PRESENT AND IF TAPERS GREATER THAN 30 DEGREES ARE FOUND, FAIR IN BY A HAND GRINDING TO ACHIEVE TAPER AND RADIUS CONFIGURATION OF REFERENCE A. PERFORM GRINDING AT NEXT SCHEDULED INDUSTRIAL AVAILABILITY. THE FOLLOWING ARE RECOMMENDED TOOLS AND PROCEDURES FOR REMOVING SHARP COUNTERBORE BEVELS (SHARPER THAN FOUR TO ONE) AND PROVIDING A 1/16 INCH RADIUS AT BEVEL BASE TO MAKE JOINTS IN ACCORDANCE WITH REFERENCE A. (1) TOOLS: (A) HAND SIZE PNEUMATIC GRINDER WITH 12 TO 16 INCH 1/4 INCH DIAMETER EXTENSIONS (MADE FROM 1/4 INCH DRILL STOCK). (B) 1/4 INCH BALL ROTARY FILE, MEDIUM COARSE, WITH INCH SHAFT THREE INCHES IN LENGTH. (C) 1/2 INCH BALL ROTARY FILE, MEDIUM COARSE, WITH INCH SHAFT THREE INCHES IN LENGTH. (D) 1/2 INCH CONE GRINDING STONE (APPROXIMATELY FOU TO ONE TAPERED CONE) WITH 1/4 INCH SHAFT 3 INCHES IN LENGTH. (E) 1-1/4 INCH LONG, 1/4 INCH SLEEVE WITH TWO SET S (TO COUPLE TOOLS TO EXTENSIONS). (2) METHODS: (A) SET MIRROR WITH MAGNETIC STAND BEYOND COUNTER- BORE BEVEL TO BE WORKED. ILLUMINATE WORK SECTION WITH SUITABLE HIGH INTENSITY LIGHT. (B) USING 1/4 INCH BALL ROTARY FILE, REMOVE SHARP B BASE AND PROVIDE RADIUSED TRANSITION FROM COUNTERBORE TO BEVEL IN ACCORDANCE WITH REFERENCE A. (C) USING 1/2 INCH BALL ROTARY FILE, "FAIR IN" BEVE REQUIRED FOUR TO ONE TAPER IN ACCORDANCE WITH REFERENCE A. (D) USING 1/2 INCH CONE GRINDING STONE DEBURR AND SMOOTH OUT RADIUS AND BEVEL. (3) QUALITY ASSURANCE: (A) FABRICATE COUNTERBORE BEVEL SLOPE GAGE (WITH FOUR TO ONE TAPER) FROM 1/8 INCH THICK SHEET METAL. (B) USING GAGE AND MIRROR WITH MAGNETIC STAND, EN- SURE EACH JOINT COUNTERBORE BEVEL IS TAPERED PROPERLY (FOUR TO ONE IN ACCORDANCE WITH REFERENCE A). (4) EXPECTED WORK RATE IS TWO FOUR INCH JOINTS PER EIGHT HOUR PERIOD IN STEAM DRUM, 1.5 JOINTS IN WATERDRUM (WATERDRUM IS SLOWER BECAUSE OF TIRESOME WORKING POSITION). C. IF TAPERS 30 DEGREES OR LESS ARE FOUND, NO CORRECTIVE ACTION IS REQUIRED. MONITOR JOINTS AT FUTURE INSPECTIONS. D. IF BACKING RING IS LOCATED IN SUCH A MANNER AS TO PRECLUDE ADEQUATE INSPECTION, A PORTION OF THE BACKING RING MAY BE REMOVED HAND GRINDING TO FACILITATE INSPECTION. E. IF JOINTS ARE ENCOUNTERED THAT ARE NOT ACCESSIBLE FOR VISUAL INSPECTION (SUCH AS HEADER CONNECTIONS) SPECIAL EQUIPMENT AND TECHNIQUES SUCH AS RADIOGRAPHY OR FIBEROPTICS WILL BE NECES- SARY. IF BACKING RING INTERFERES WITH INSPECTION OF THESE JOINTS AND CANNOT BE GROUND OUT, STUBBING OR REPLACEMENT OF TUBE MAY BE REQUIRED. 8. NAVSSES WILL DISTRIBUTE SKETCHES AND PHOTOGRAPHS BY 1 JUNE 1987 SHOWING THE CONFIGURATION OF ACCEPTABLE AND UNACCEPTABLE TAPERS, CRACK LOCATIONS AND TAPER MEASUREMENT TECHNIQUES. 9. ACTIVITIES PERFORMING HAND GRINDING OF TAPERS ARE ENCOURAGED TO CONDUCT TRAINING OF PERSONNEL ON MOCK-UPS PRIOR TO GRINDING ON A BOILER. NAVSSES WILL PUBLISH BY 15 JUNE 1987 PHOTOGRAPHS AND SKETCHES OF TRAINING MOCK-UPS USED HERE FOR SUCH TRAINING. 10. NAVSSES WILL PUBLISH BY 1 JULY 1987 AND ADVANCE CHANGE NOTICE TO NSTM 8010 GIVING DETAILS OF DOWNCOMER REPAIR TECHNIQUES. THIS ADVISORY IS APPLICABLE TO ALL SHIPS LISTED IN PARAGRAPH 4 ABOVE.
LPD-1