ASME VIII（英文）培训资料

nullnullASME Section VIII, Division 1 for Unfired Pressure VesselsnullNBNATIONAL BOARD OF BOILER AND PRESSURE VESSEL INSPECTORS “THE COPS”ENFORCEMENT LAW JURISDICTIONS EXEMPTIONSnullASME Section VIII CAN APPLY ONLY TO VALVES SET 15 psig [1.03 barg] & HIGHER null AG/C CAN PROVIDE PRVs BUILT TO THE REQUIREMENTS OF ASME SECTION VIII AND SET LOWER THAN 15 psig [1.03 barg]BUT WITHOUT A CODE STAMPnull THE ASME DOES NOT CERTIFY OR APPROVE ANY DEVICE THE NATIONAL BOARD CERTIFIES VALVE CAPACITY AND VERIFIES VALVE COMPLIANCE WITH THE ASME CODE.nullNB Method of Certifying CapacityAT AN “ASME APPROVED” TEST FACILITY, FLOW EACH OF 9 TOTAL VALVES AT 110% OF SET PRESSURE (3 VALVE SIZES, 3 SET PRESSURES) ESTABLISH THE “KD” FOR EACH TEST VALVE (CONSIDERING THE FLOW CONDITIONS AND EACH MEASURED ORIFICE AREAKD= FLOW OF A “PERFECT NOZZLE”nullCALCULATE THE AVERAGE “KD” FOR THE 9 TEST VALVES NO TEST VALVE’S “KD” CAN DEVIATE MORE THAN ±5% FROM THE AVERAGE ESTABLISH THE ASME “K” K = AVERAGE KD x 0.90 THE ACTUAL “KD”, “K”, AND “A” (ORIFICE AREA) VALUES ARE PUBLISHED FOR ALL CODE-STAMPED PRVs IN THE NATIONAL BOARD “RED BOOK”NB Method of Certifying Capacity (cont’d)nullIN 1962, THE CODE WAS REVISED REQUIRING THAT “K” BE USED IN SIZING CALCULATIONS (10% “SAFETY FACTOR”) INSTEAD OF “KD”. nullFor Gas FlowCKAPMTZW = THE NB ALLOWS PUBLISHED DEVIATIONS FROM “K” AND “A” VALUES IN THE “RED BOOK”. HOWEVER - - ADVERTISED KA ASME KA (NB “Red Book”) V= nullSINCE 1962, MOST PRV MANUFACTURERS HAVE OVERSTATED THEIR “K” VALUES AND UNDERSTATED THEIR “A” VALUES.null Example: Gas Service “J” ORIFICE (API = 1.287 in2) [8.303 cm2]NATIONAL BOARDVENDOR CATALOG K A, in2 [cm2] KA K A, in2 [cm2] KAFARRIS POPRVCONSOLIDATED DSOPRVAG/C POPRV0.8780.8550.8771.459 [9.413]1.496 [9.652]1.496 [9.652]1.281 [8.264]1.279 [8.252]1.312 [8.464]0.9530.950.9751.287 [8.303]1.287 [8.303]1.287 [8.303]1.248 [7.913]1.223 [7.888]1.255 [8.096]null3.5:1* Factor of Safety for Pressure Containing Components EXAMPLES: BODY WALL THICKNESS CLOSED BONNET WALL THICKNESS BONNET BOLTS BONNET BOLT THREADS IN BODY * was 4:1 until 1999nullBlocked DischargeFULL INPUT FLOWOUTLET BLOCK VALVE CLOSED(FROM COMPRESSOR OR PUMP)PRDPressure VesselnullASME Section VIII, % MAWPMAWP (MAX. SET)BLOCKED DISCHARGEONE PRD ALLOWABLE OVERPRESSURE : 10% OR 3 PSIG, [0.20 BARG] WHICHEVER IS GREATER110100nullASME Section VIII, % MAWPMULTIPLE PRDs1ST VALVE MAXIMUM SET: MAWP ALLOWABLE OVERPRESSURE: 16%2ND VALVE MAXIMUM SET: 105% MAWP ALLOWABLE OVERPRESSURE: 10%BLOCKED DISCHARGEMAWP1ST1161051002NDnullExternal FirePRDnullASME Section VIII, % MAWPMAWP12110021%1 VALVE ALLOWABLE OVERPRESSURE: 21%FIREnullASME Section VIII, % MAWPMAXIMUM SET: 1ST VALVE: MAWP 2ND VALVE: 110% OF MAWPALLOWABLE OVERPRESURE: 1ST VALVE: 21% 2ND VALVE: 10%1ST VALVE121MAWP1001102ND VALVEFIRE 2 VALVESnullSAFETY & RELIEF VALVES SHALL BE OF THE DIRECT SPRING-LOADED TYPE. PILOT OPERATED VALVES MAY BE USED IF: PILOT IS SELF ACTUATED. VALVE WILL FAIL-SAFE OPEN IF ESSENTIAL PART WITHIN PILOT SHOULD FAIL.nullPilot Operated Pressure Relief ValveOutPilotInnullPRV Set Pressure Tolerance UP TO 70 psig [4.83 barg] SET ---- ± 2 psig [0.14 barg] OVER 70 psig [4.83 barg] SET ---- ± 3%NAMEPLATESET PRESSUREnullTHE PRV MUST BE CAPABLE OF BEING RESET DIFFERENT FROM FACTORY NAMEPLATE SET PRESSURE BY ± 5% WITH NO CHANGE OF PARTS OR IMPAIRED PERFORMANCE (INSTABILITY, NOT FULL LIFT AT 10% OP). EXAMPLE: NAMEPLATE SET = 1000 psig [69 barg] CAN BE RESET TO 950 - 1050 psig [66-72 barg] nullTypical Full Nozzle Spring Valve 3K4USED VALVE5%5%233 psig [16.07 barg]181 psig [12.48 barg]191 psig [13.17 barg] 222 psig [15.31 barg] PUBLISHED SPRING RANGE (NEW VALVE)nullCan Reset 5% of Nameplate Set+ -nullInlet Riser Flow Area Must be at Least as Large as the PRV Orifice Area nullINLET PIPING PRESSURE DROP MUST NOT REDUCE PRD CAPACITY BELOW THAT REQUIRED OR ADVERSELY AFFECT PRV OPERATION.(NOT 3% MAXIMUM)null MUST NOT REDUCE PRD CAPACITY BELOW THAT REQUIRED MUST NOT ADVERSELY AFFECT THE PRV OPERATIONPRD Discharge PipingnullNo Liquid Head. Cleaner Valve.Vapor SpaceLiquidGas/Vapor PRVnullPER ASME SECTION VIII AND API RP520OUTLETINLETINLETAVOIDINSTALL PRV IN UPRIGHT VERTICAL POSITIONOUTLETnullEFFECTIVE 1-1-85, PRV’S FOR ALL-LIQUID SERVICE MUST HAVE CAPACITY AND OPERATION CERTIFIED ON WATER. VALVE MANUFACTURER MUST:SET THE VALVE ON WATER. STAMP NAMEPLATE CAPACITY IN “GPM WATER”. ONLY 10% OVERPRESSURE IS ALLOWED (NOT PREVIOUS 25%).Liquid ServicenullVesselDRAIN AT LOW POINT OF DISCHARGE (INCLUDES CLOSED HEADERS)nullASME REQUIRES A LIFT LEVER FOR SERVICES ON:AIR STEAM HOT WATER (> 140°F) [> 60°C]nullLift Lever (Direct Spring PRV)nullLift Lever (Pilot Operated PRV)nullPilot Operated ValvesA FIELD TEST CONNECTION IS ALLOWED IN LIEU OF LIFT LEVER IF BOTH PILOT AND MAIN VALVE CAN BE ACTUATED BY IT.(AS OF 1988)nullField Test Activation of Pilot Operated PRVACTIVE PROCESSnullHowever AIR STEAM HOT WATER ( > 140°F) [>60°C]DELETION OF LIFTING DEVICE REQUIREMENTS ALLOWED FOR PRV’S ON:IF1. THE OMISSION IS SPECIFIED BY THE PURCHASER. EXAMPLE: “IN ACCORDANCE WITH ASME CODE CASE 2203, THE LIFTING DEVICE IS OMITTED”. 2. THE USER HAS A DOCUMENTED PROCEDURE AND IMPLEMENTATION PROGRAM FOR PERIODIC REMOVAL OF THE PRV’S FOR INSPECTION, TESTING AND REPAIR AS NECESSARY. 3. THE USER OBTAINS PERMISSION FOR THIS DELETION FROM JURISDICTIONAL AUTHORITIES.nullBlock Valves are Permitted for Inspection or Maintenance OnlyFULL AREALOCKED IN OPEN POSITIONIF CLOSED - PERSON SHALL REMAIN AT VALVE TO MONITOR SYSTEM PRESSUREBLOCK VALVEnullDISCHARGE HEADERBLOCK VALVE HERE - - -REQUIRES BLOCK VALVE HERE ALSO, PREFERABLY INTERLOCKED WITH DOWNSTREAM BLOCK VALVEnullFactory Proof Test of Primary Section of PRVOVER 1” [25 mm] INLET SIZE OR SET PRESSURE OVER 300 psig [20.7 barg] PRESSURE TEST TO AT LEAST 1.5 TIMES DESIGN PRESSURE OF VALVE (1 minute) NO LEAKAGE ALLOWED.nullFactory Test of Discharge Section of PRVOVER 1” [25 mm] INLET SIZE AND WHEN PRV DISCHARGES INTO HEADER AND BONNET IS A CLOSED DESIGN. GAS PRESSURE TEST OF AT LEAST 30 psig [2.04 barg]. NO LEAKAGE ALLOWED.nullSeat TightnessMUST BE IN ACCORDANCE WITH API 527.nullAPI 527 Leak Test For Gas Service1/4” [6.4 mm] I.D.90% OF SET PRESSURE1/2” [13 mm]nullAPI 527 For Gas ServicenullAssemblersCODE STAMP BY ASSEMBLER INDICATES THE USE OF ORIGINAL, UNMODIFIED PARTS, IN STRICT ACCORDANCE WITH THE MANUFACTURERS INSTRUCTIONS.NORMALLY AGREED TO BY MANUFACTURER(S) TO STOCK COMPLETE PRVS & PARTSnullRupture Discs with PRVnullRD Burst Pressure ToleranceUP TO 40 psig [2.76 barg] - - - OVER 40 psig [2.76 barg] - - -2 psig [0.14 barg] 5%STAMPEDBURST PRESSUREnullRupture Disc Under PRVSPACE BETWEEN RD AND PRV MUST BE MONITORED PRV CAPACITY EITHER DERATED BY 10% OR NB COMBINATION FACTOR USED (TYPICALLY 1 TO 3% REDUCTION) SPRING PRV SHOULD BE SET BELOW RD BURST PRESSURE TO ENSURE PRV OPENS WHEN RD BURSTS.nullRupture Disc on PRV OutletSPACE BETWEEN RD AND PRV MUST BE VENTED PRV MUST BE BALANCED AGAINST BACK PRESSUREnullBenefits of ASME Code-Stamped PRVsCERTIFIED CAPACITIES OF 9 VALVES (3 SIZES, 3 SET PRESSURES) BY AN INDEPENDENT, REGULATORY GROUP VALVE OPERATING STABILITY CONFIRMED WITH PROPER COMPANION PIPING MINIMUM 3.5:1 FACTOR OF SAFETY FOR ALL PRESSURE RETAINING COMPONENTS CONTROLLED, MAXIMUM SPRING COMPRESSION