API STD 510:2001 pdf download
API STD 510:2001 pdf download.Pressure Vessel lnspection Code:Maintenance Inspection, Rating, Repair, and Alteration.
5.3CORROSION RATE DETERMINATION
For a mew vescl or for a vosscl for which servicc condi-tions are bcing changod,onc of thc following mcthods shallhe employe lo dletermine the vessel ‘s probable corrosionratc.Thc rcmaining wall thickncss an thc timc ol thc ncx1inspection can be estimated from this rale.
a. A corrosion ratc may bc calculatcd from data collcctcdby the owner or user on vessels providing the same or simi-lar scrvicc.
h. If data on vcsscls providing thc samc or similar scrvice arcnol available.a corrosion rale may be estimated fron theowncr’s or uscr’s cxpcricncc or from publishcd data on vcs-scls providing comparablc scrvicc.
c. Il thc probablc conrosion ralc cannot bc dctcrmincd byeither item a or ilem b above, onl-stream determinations shallbc madc aftcr approximatcly 1000 hours of scrvicc by usingsuitable corrosion monitoring devices or aclual nondlestruc-tivc thickncss mcasurcmcnts of thc vcsscl or systcm. Subsc-quent determninations shall be made alier appropriale intervalsuntil thc corrasion ratc is cstablishod.
lf it is deicrrmincd that an inaccuralc corrosion ratc hasheen assumed,the rale to be usedi for the next periocd shall beincrcasod or may bc dccrcascd to agrce with thc aclual ralc.5.4MAXIMUM ALLOWABLE WORKING
PRESSURE DETERMINATION
Thc maximum allowablc working prcssuLrc for thc contin-uod usc ol a prcssurc vcsscl shall bc bascd on computationsthat are dketcrnined using the latest edition of the ASMECodc or thc consInuction codc to which thc vcsscl was built.
The resulting maxinmum allowable working pressure fromthcsc computations shall not bc grcatcr than thc original max-
imum allowable working pressure unless a rerating is per-formod in accordancc with 7.3.
Computations may bc madc only ifthe lollowing csscntialdclails comply with thc applicablc rcquircmcnts ol thc codcheing used; heacl,shell，and nozle rein forcemenl designs;matcrial spccifications; allowablc strcsscs; wcld cfficicncics;inspection acceplance criteria; and cyclical service require-mcnts. In corrosivc scrvicc. thc wall thickncss uscd in thcsccomputations shall be the actual thickness as determined byinspcction (soc 5.7) minus twicc the cstimatcd corrosion lossbcfore the date of the nex1 inspection. except as modified in6.4.If the actial thickncss dkctcrmincdi by inspcetion is grcalcTthan thc thickncss reportcd in thc malcrial icst report or thcrmanuufxclurer’s cala report,il must he confirmedi by multiplethickncss mcasurcmcnts,takcn at arcas whcrc thc thickncss ofthe component in qucstiom was mosl likely allecied by thethinning duc to forming.Thc thickncss mcasurcmcnt procc-cure shall be approved by the authorized pressure vesselinspcctor. Allowancc shall bc madc for othcr loads in accor-cJance with the applicable provisions of the ASML Code.
5.5 DEFECT INSPECTION
Vcsscls shall bc cxaminod for visual indications of distor-tion. If any distortion of a vesszel is suspected or observed, theovcrall dimcnsions of thc vcsscl shall bc chcckod to confim
whether or nol the vessel is cistoried andtl,i rioh Thc nartscietcrmine the cxtcnt amdd scricxusncss of the distortion.Thc parts
of thc vesscll that should bc inspcctcd mosn carclully cdctphenrd onthe iype ol’ vessel and its operaling conclitioms The auihorirexi
prcssurc vcsscl inspcctor should bc familiar with thc opcratingconcditions of the vessel and with the causes and characteris-tics of potcntial dcfccts and dctcrioration.(For rccommendcdinspeclion practices for pressure vessels, see APl RP 572.)Carelul visual examination is the nost imporlant and themost univcrsally acccptcd mcthod of inspcction.Othcr mcth-ods that nay be used io supplement visual inspection include(a) magnctic-particlc cxamination for cracks and other clon-
dyc-pcmctrant cxamination for diselosing cracks, porosity, orpin holcs thal cxtcnd to thc surlacc ol thc malcrial and lor
outlining other surlatce imperfectioms,especially in nonmag-nctic matcrials; (c) radiographic cxamination;(d ultrasonic thickness measurement and flaw detection; (ey eddy currentcxamination; (fmctallograplic cxamination; (g)acousticcmission testing; hammer testing while non under pressure;and (h) prcssurc testing.
