4-1/2" SCH40是什么意思？

4-1/2" SCH40是什么意思？

Industrialpipethicknessesfollowasetformula,expressedasthe"schedulenumber"asestablishedbytheAmericanStandardsAssociation(ASA)nowre-organizedasANSI-theAmericanNationalStandardsInstitute.Elevenschedulenum最则与集是员bersareavailableforuse:5,10,20,30,40,60,80,100,120,140,&160.Themostpopularschedule,byfar,is40.Sch5,60,100,120,&140haverarely,ifeverbeenemployedbymyselfinover40yearsasapracticingengineer.Theschedulenumberisdefinedastheapproximatevalueoftheexpression:

Schedule#=(1,000)(P/S)

Where,

P=theinternalworkingpressure,psig

S=theallowablestress(psi)forthematerialofconstructionattheconditionsofuse.

Forexample,theschedulenumberofordinarysteelpipehavinganallowablestressof10,000psiforuseataworkingpressureof350psigwouldbe:

Schedule=(1000)(350/10,000)=35(approx.40)

Thiswouldbetheproperscheduleforweldedjointsandsteelfitt来自ingsbutnotfort360问答hreadedconnectionsandcast-ironormalleable-ironfittings.Inpr防困川政并快松见苦外actice,sch井探张edule40wouldbeusedforweldedconstructiona背宽何光屋阶ndSch80(abo谁种粮三ut2xthecomputedvalue)forironfittings.Thehigherscheduleisrequiredbecauseofweaknessestheironfittingsandthemetallostincuttingthethreads.

Forallpipesizesbelow10",Sch40pipeisidenticalwithwhatwasoncecalled"standard"pipe,andSch80isidenticalwitht技县防重议装普heformer"extra-strong"pipe.Thereisno大临equivalentschedulenumberfor"d随ouble-extra-strong"pipe,andSch160is优正印类带致料显theonlyot依毛胡服前必预含承告切herweightinwhichp们ipesmall庆左夜erthan4"isavailable.

Temperaturehasnodirectbearingontheschedule,exceptasiteitherweakens(orstrengthens)thematerial'sallo婷执行声月罪样片改wablestre停浓始丰行年备组花ss.Stainles想乱量挥电接率力ssteels(304ELC&316ELC),forexampleyieldastrongerallowablestressatthelowtemperaturesnearthecryogeniczone(-50to-150oF).CopperandBrassalsoexhibitthesamebehavior.I'veusedtheruleofthumbthatt补换望赵刘继室资承hesofterthemetal,the使结越草参沙远盾strongeritisatthelowertemperatures.