钢管壁厚表示方法Word下载.docx
《钢管壁厚表示方法Word下载.docx》由会员分享,可在线阅读,更多相关《钢管壁厚表示方法Word下载.docx(12页珍藏版)》请在冰豆网上搜索。
2)以钢管壁厚尺寸表示中国、ISO、日本部分钢管标准采用钢管壁厚表示方法钢管壁厚表示方法钢管壁厚表示方法有管子表号、钢管壁厚尺寸和管子重量三种方法1)是以管子表号"
3)是以管子重量表示管壁厚度,它将管子壁厚分为三种:
a.标准重量管,以STD表示钢管壁厚表示方法钢管壁厚表示方法钢管壁厚表示方法有管子表号、钢管壁厚尺寸和管子重量三种方法1)是以管子表号"
b.加厚管,以XS表示钢管壁厚表示方法钢管壁厚表示方法钢管壁厚表示方法有管子表号、钢管壁厚尺寸和管子重量三种方法1)是以管子表号"
c.特厚管,以XXS表示。
对于DN≤250mn的管子,Sch40相当于STD,DN<
200mm的管子,Sch80相当于XS。
8"
SCH40"
:
是DN200,外径为8.625in=219mm壁厚为0.322in=8.1788mm钢管壁厚表示方法钢管壁厚表示方法钢管壁厚表示方法有管子表号、钢管壁厚尺寸和管子重量三种方法1)是以管子表号"
没有8“SCH4012”8"
SCH4014"
的规格!
NominalPipeSize
FromWikipedia,thefreeencyclopedia
NominalPipeSize(NPS)isaNorthAmericansetofstandardsizesforpipesusedforhighorlowpressuresandtemperatures.[1]Pipesizeisspecifiedwithtwonon-dimensionalnumbers:
anominalpipesize(NPS)fordiameterbasedoninches,andaschedule(Sched.orSch.)forwallthickness.NPSisoftenincorrectlycalledNationalPipeSize,duetoconfusionwithnationalpipethread(NPT).TheEuropeandesignationequivalenttoNPSisDN(diamè
trenominal/nominaldiameter),inwhichsizesaremeasuredinmillimetres.[2]ThetermNB(nominalbore)isalsofrequentlyusedinterchangeablywithNPS.
Contents
▪1History
▪2Application
3NPStablesforselectedsizes
3.1NPS⅛toNPS3½
3.2NPS4toNPS9
3.3NPS10toNPS24
3.4NPS26toNPS36
3.5Additionalsizes(NPS)
▪4Seealso
▪5Notes
6References
6.1Bibliography
▪7Externallinks
[edit]History
InMarch1927,theAmericanStandardsAssociationauthorizedacommitteetostandardizethedimensionsofwroughtsteelandwroughtironpipeandtubing.Atthattimeonlyasmallselectionofwallthicknesseswereinuse:
standardweight(STD),extra-strong(XS),anddoubleextra-strong(XXS),basedontheironpipesize(IPS)systemoftheday.Howeverthesethreesizesdidnotfitallapplications.Thecommitteesurveyedtheindustryandcreatedasystemofschedulenumbersthatdesignatedwallthicknessesbasedonsmallerstepsbetweensizes,[3]althoughIPSandNPSnumbersremainequivalent.
Theoriginalintentwasthateachschedulewouldrelatetoagivenpressurerating,howeverthenumbersdeviatedsofarfromwallthicknessesincommonusethatthisoriginalintentcouldnotbeaccomplished.[3][note1]Also,in1939,itwashopedthatthedesignationsofSTD,XS,andXXSwouldbephasedoutbyschedulenumbers,howeverthoseoriginaltermsarestillincommonusetoday(althoughsometimesreferredtoasstandard,extra-heavy(XH),anddoubleextra-heavy(XXH),respectively).Sincetheoriginalscheduleswerecreated,therehavebeenmanyrevisionsandadditionstothetablesofpipesizesbasedonindustryuseandonstandardsfromAPI,ASTM,andothers.[3]
Stainlesssteelpipes,whichwerecomingintomorecommonuseinthemid20thcentury,permittedtheuseofthinnerpipewallswithmuchlessriskoffailureduetocorrosion.By1949thinnerschedules5Sand10S,whichwerebasedonthepressurerequirementsmodifiedtothenearestBWGnumber,hadbeencreated,andother"
S"
sizesfollowedlater.Duetotheirthinwalls,thesmaller"
sizescannotbethreadedtogetheraccordingtoASMEcode,butmustbefusionwelded.[4]
[edit]Application
BasedontheNPSandscheduleofapipe,thepipeoutsidediameter(OD)andwallthicknesscanbeobtainedfromreferencetablessuchasthosebelow,whicharebasedonASMEstandardsB36.10MandB36.19M.Forexample,NPS14Sch40hasanODof14inchesandawallthicknessof0.437inches.HowevertheNPSandODvaluesarenotalwaysequal,whichcancreateconfusion.
▪ForNPS⅛to12inches,theNPSandODvaluesaredifferent.Forexample,theODofanNPS12pipeisactually12.75inches.TofindtheactualODforeachNPSvalue,refertothetablesbelow.(Notethatfortubing,thesizeisalwaystheactualOD.)
▪ForNPS14inchesandup,theNPSandODvaluesareequal.Inotherwords,anNPS14pipeisactually14inchesOD.
ThereasonforthediscrepancyforNPS⅛to12inchesisthattheseNPSvalueswereoriginallysettogivethesameinsidediameter(ID)basedonwallthicknessesstandardatthetime.However,asthesetofavailablewallthicknessesevolved,theIDchangedandNPSbecameonlyindirectlyrelatedtoIDandOD.
ForagivenNPS,theODstaysfixedandthewallthicknessincreaseswithschedule.Foragivenschedule,theODincreaseswithNPSwhilethewallthicknessstaysconstantorincreases.UsingequationsandrulesinASMEB31.3ProcessPiping,itcanbeshownthatpressureratingdecreaseswithincreasingNPSandconstantschedule.[note1]
Somespecificationsusepipeschedulescalledstandardwall(STD),extrastrong(XS),anddoubleextrastrong(XXS),althoughtheseactuallybelongtoanoldersystemcalledironpipesize(IPS).TheIPSnumberisthesameastheNPSnumber.STDisidenticaltoSCH40S,and40Sisidenticalto40forNPS1/8toNPS10,inclusive.XSisidenticaltoSCH80S,and80Sisidenticalto80forNPS1/8toNPS8,inclusive.XXSwallisthickerthanschedule160fromNPS1/8"
toNPS6"
inclusive,andschedule160isthickerthanXXSwallforNPS8"
andlarger.
The"
designation,forexample"
NPSSch10S"
mostoftenindicatesstainlesssteelpipes.Howeversomestainlesssteelpipesareavailableinsteeldesignations,sostrictlyspeakingthe"
designationonlydifferentiatesB36.19MpipefromB36.10Mpipe.[1]
Bothpolyvinylchloridepipe(PVC)andchlorinatedpolyvinylchloridepipe(CPVC)aremadeinNPSsizes.
[edit]NPStablesforselectedsizes
[edit]NPS⅛toNPS3½
NPS[5]
DN
[2]
OD
[in(mm)]
Wallthickness
SCH5
SCH10s/10
SCH30
SCH40s/40
/STD
SCH80s/80
/XS
SCH120
SCH160
XXS
⅛
6
0.405(10.29)
0.035(0.889)
0.049(1.245)
0.057(1.448)
0.068(1.727)
0.095(2.413)
—
¼
8
0.540(13.72)
0.065(1.651)
0.073(1.854)
0.088(2.235)
0.119(3.023)
⅜
10
0.675(17.15)
0.091(2.311)
0.126(3.200)
½
15
0.840(21.34)
0.083(2.108)
0.109(2.769)
0.147(3.734)
0.188(4.775)
0.294(7.468)
¾
20
1.050(26.67)
0.113(2.870)
0.154(3.912)
0.219(5.563)
0.308(7.823)
1
25
1.315(33.40)
0.114(2.896)
0.133(3.378)
0.179(4.547)
0.250(6.350)
0.358(9.093)
1¼
32
1.660(42.16)
0.117(2.972)
0.140(3.556)
0.191(4.851)
0.382(9.703)
1½
40
1.900(48.26)
0.125(3.175)
0.145(3.683)
0.200(5.080)
0.281(7.137)
0.400(10.160)
2
50
2.375(60.33)
0.218(5.537)
0.343(8.712)
0.436(11.074)
2½
65
2.875(73.03)
0.120(3