I-Incoloy Alloy Parts: 825 vs 800 yeNkonzo ye-Corrosive 

Xa injineli ichaza i inxalenye ye-incoloy kumgca ongcolisayo, ukhetho phakathi kwe-Alloy 825 kunye ne-Alloy 800 kunqabile malunga nokuba yeyiphi i-alloy "engcono." Imalunga nokuba yeyiphi i-alloy ehambelana neyona meko yenkonzo. I-Incoloy 825 (UNS N08825) yenzelwe ukunciphisa i-acids, i-chloride-bearing media, kunye neendawo zegesi ezimuncu. I-Incoloy 800 (i-UNS N08800) yenzelwe amandla aphezulu obushushu kunye nokumelana ne-oxidation, kunye nokusebenza kwe-corrosion kwimidiya yamanzi njengenzuzo yesibini. Ukubhidanisa ezi zimbini kunokukhokelela kwiindleko ezingeyomfuneko okanye i-alloy engahambelani neemfuno zenkonzo.

Olu thelekiso lubhalelwe iikhemikhali, i-offshore, kunye neenjineli zokutshintsha ubushushu kunye nabathengi abafuna isakhelo esisebenzayo sokhetho, hayi incwadi yezixhobo ezibanzi. Igxininisa kwingqiqo ye-metallurgical emva kwe-alloy nganye, ifom yecandelo apho ukhetho lubaluleke kakhulu, kunye nokwakhiwa kunye nokuthengwa kwamanqaku aqinisekisa ukuba i-alloy echaziweyo iyasebenza ngokwenene enkonzweni.

I-Incoloy 825 vs 800: Umahluko we-Positioning

Eyona ndlela ilula yokwenza isakhelo umahluko yile: I-alloy 825 yi-corrosion-first; I-alloy 800 ishushu kuqala.

I-alloy 825 yeyosapho lwe-Ni-Fe-Cr-Mo-Cu. Umxholo wayo we-nickel uhlala kwi-38-46% yoluhlu, kunye nokongezwa ngamabomu kwe-molybdenum (2.5-3.5%) kunye nobhedu (1.5-3.0%), kunye nokuzinza kwe-titanium. Le ndibaniselwano yenzelwe ukuphatha zombini i-oxidizing kunye nokunciphisa i-acids, ukuxhathisa i-chloride yoxinzelelo lwe-corrosion cracking, kunye nokunyamezela iimeko zenkonzo ezimuncu eziqukethe i-H₂S.

I-alloy 800 yi-alloy ye-Ni-Fe-Cr emalunga ne-30-35% ye-nickel kunye ne-19-23% ye-chromium, kodwa akukho molybdenum ngenjongo kwaye akukho kufakwa kobhedu. Injongo yayo yoyilo yinkonzo yobushushu obuphezulu: ukumelana ne-oxidation, ukuxhathisa kwe-carburization, kunye namandla okunyuka kumaqondo obushushu ukuya malunga ne-593 ° C kwi-base 800 grade, kunye ne-800H kunye ne-800HT yokwandisa olo luhlu ngakumbi. Kwimithombo yemithombo yamanzi e-aqueous corrosive ngaphandle kwe-chloride enzima okanye ukunciphisa ukubonakaliswa kwe-asidi, i-800 yenza ngokufanelekileyo, kodwa ukuxhathisa ukubola kwayo kuncinci ngokuyila.

Kweye inxalenye ye-incoloy kumgca wenkqubo yeekhemikhali yokuphatha i-sulfuric acid kunye ne-chlorides, i-825 yinkcazo efanelekileyo. Ukufumana inkxaso yesithando somlilo okanye i-high-temperature yokuxhuma ikhonkco, i-800 idla ngokufanelekileyo kwaye ikhetha ukonga. Isigqibo kufuneka silandele eyona ndlela ibalaseleyo yokuthotywa, hayi igama eliqhelekileyo lealloyi.

Ukubunjwa kunye neendlela zokuxhathisa ukonakala

Yintoni eyenziwa yiNickel, iChromium, iMolybdenum, kunye neCopper

Ukuxhatshazwa kwe-corrosion ye-Alloy 825 ayikho into enye. Udibaniso ngalunye ludibanisa indlela ethile yokusilela.

I-Nickel inika isiseko sokumelana ne-chloride yoxinzelelo lwe-corrosion cracking (SCC). Uluhlu lwe-nickel lwe-38-46% kwi-825 lwanele ukuxhathisa i-chloride-ion SCC kwiindawo ezininzi. I-alloy 800 ye-nickel ephantsi yomxholo we-nickel (30-35%) inika kwakhona ukunyanzeliswa kwe-SCC kwimithombo emininzi yamanzi, kodwa i-nickel ephezulu kwi-825 inikeza umda obanzi kwinkonzo ye-chloride enzima.

I-Chromium yenza ifilimu ye-oxide ye-passive ekhusela kwimidiya ye-oxidizing efana ne-nitric acid kunye neetyuwa ze-oxidizing. Zombini i-800 kunye ne-825 zixhomekeke kwi-chromium kulo msebenzi, kwaye zombini ziqulethe malunga ne-19-23.5% ye-Cr.

I-Molybdenum yindawo apho i-alloys ezimbini zihlukana ngokucacileyo. I-2.5-3.5% ye-Mo kwi-825 iphakamisa ukuxhathisa kwi-pitting kunye ne-crevice corrosion, ngokukodwa kwiindawo ezithwele i-chloride. Ingxubevange 800 ayiqulathanga ngabom molybdenum Ukongeza. Oku kungabikho akusiyo isiphene kwi-design ye-800; ibonisa ngokulula ukuba i-800 ayizange yenzelwe ukuxhathisa imingxuma yekloridi.

I-Copper, ekhoyo kwi-1.5-3.0% kwi-825, isebenza kunye ne-molybdenum ukuxhathisa ukunciphisa i-acids, ngakumbi i-sulfuric kunye ne-phosphoric acid. I-alloy 800 ayinayo ukongeza ubhedu. Kwinkonzo ye-sulfuric acid dilute, umxholo wobhedu we-825 sesona sizathu sichazwe apho i-800 ayiyi kuba.

I-Titanium kwi-825 isebenza njenge-stabilizer, ibopha i-carbon ukukhusela i-chromium carbide precipitation ngexesha le-welding kunye nokunciphisa umngcipheko wokuvuselela. Kungenxa yoko le nto i-825 ichazwa njengokumelana nokubola kwe-intergranular kwimeko ye-welded.

Yintoni i-800 yokunqongophala kwe-Mo kunye ne-Cu ithetha kwi-Practice

I-alloy 800 ayifanele igxothwe njenge "i-corrosion resistant" kuyo yonke imixholo. Kwi-atmospheres ye-oxidizing ephezulu yokushisa, umxholo we-chromium we-800 kunye nebhalansi ye-nickel inika i-oxidation egqwesileyo kunye nokuchasana kwe-carburization, yingakho ihlala iyinto esemgangathweni ye-reformer kunye ne-furnace components. I-alloy inika ukuchasana kokubola ngokubanzi kwimithombo yeendaba ezininzi ezinamanzi kwaye imelana noxinzelelo lwe-corrosion cracking kwiindawo ezininzi.

Unyino lubonakala xa imeko-bume yenkonzo ibandakanya iikloridi kunye ne-asidi yokunciphisa, okanye xa i-pitting kunye ne-crevice corrosion izisoyikiso ezikholelekayo. Kwezo meko, i-800 yokungabikho kwe-molybdenum ishiya isengozini yokuhlaselwa kwendawo yokuba i-825 yenzelwe ukuxhathisa. Umsebenzi wovavanyo kumacandelo okushisa kwangaphambili kunye noxinzelelo lwekloride ephezulu (5,500 ppm Cl⁻) kwiqondo lokushisa eliphakamileyo lifumene ukuba i-Incoloy 800 ibonise ukubola kwemigodi ngelixa i-Incoloy 825 ingabonakalisi ukubola okubalulekileyo phantsi kweemeko ezifanayo. Olu hlobo lobungqina obuthelekisekayo, ngelixa lukhethekileyo kwimeko-bume yovavanyo, lubonisa isiphumo esisebenzayo somahluko wokuhlanganisa.

Kweye inxalenye ye-incoloy kwindawo yokufudumeza ubushushu obupholileyo ngamanzi olwandle, lo mahluko ubalulekile. Amanzi olwandle adibanisa ikloridi, iimeko zokunciphisa ngamaxesha athile kwi-biological activity, kunye nemingxuma kwiiflange kunye ne-tube-to-tubesheet joints. I-alloy 825 ye-Mo kunye ne-Cu umxholo ngokuthe ngqo kwezi ndlela. I-alloy 800 ayifuni.

Iifom zeCandelo le-Incoloy eqhelekileyo kunye neemeko zeSicelo

IiWasher ze-Icoloy kunye neFastener Components

Iiwasha zihlala kwindawo engaxoleliyo kwindawo edityanisiweyo: zixinzelelwe phakathi kwemigangatho emibini, zenza umkrozo apho ukuncipha kweoksijini kunye nokuxinana kwekloridi kunokukhawulezisa ukuhlasela. Kwinkonzo ephethe i-chloride, i-washer kufuneka ixhathise ukubola okuqhelekileyo kunye ne-crevice corrosion ngelixa igcina ukulayisha kwangaphambili.

I-alloy 825 washers luphawu olufanelekileyo lokudityaniswa kwe-flanged kwigesi emuncu, amanzi olwandle, kunye neenkqubo zokuphatha i-asidi. Umxholo we-molybdenum ubonelela nge-pitting kunye ne-crevice corrosion resistance that 800 ayinakuhambelana. I-high-temperature flue gas okanye izicelo zesithando somlilo apho i-chlorides ingekho kwaye ukuzinza kwe-thermal yinto ephambili, i-800 washers inokuqwalaselwa.

Inqaku elinye elisebenzayo elivela kumava omatshini: I-Incoloy alloys isebenza nzima ngexesha lokujika kunye nokuthunga, kwaye izinga lokuqiniswa komsebenzi kwi-825 liphezulu kakhulu nangona lingaphantsi kuneentsimbi eziqhelekileyo ze-austenitic. Iiwasha ezibhityileyo ngaphantsi kwe-1.5 mm zinokugqwetheka ngexesha lonyango lobushushu ngaphandle kokuba zixhaswe ngokulungiswa okufanelekileyo. Ukuqengqeleka komsonto endaweni yokucofa kudla ngokukhethwa kuyilo lwewasha enemisonto kwinkonzo yekloride, kuba ukucofa kunokwazisa umonakalo ongaphantsi komhlaba othi ube yindawo yokuqaliswa koxinzelelo lokuqhekeka komhlwa. Inqaku lokuqinisekisa: Esi sikhokelo sokwenziwa sibonisa ubuchwephesha obuqhelekileyo bezinto ezixutywe ne-Incoloy; iiparamitha ezithile kufuneka ziqinisekiswe kunye nomenzi wangempela.

I-Incoloy Tube kunye ne-Heat Exchanger Parts

I-ASTM B423 / ASME SB423 igubungela ityhubhu engenamthungo kunye nebandayo esebenza kwi-UNS N08825 yenkonzo eyonakalisayo jikelele. Kwityhubhu yokutshintsha ubushushu, ukhetho phakathi kwe-825 kunye ne-800 ngokuqhelekileyo lulandela i-shell-side okanye i-tube-side chemistry.

Ukuba icala lombhobho lithwala amanzi okupholisa ngekloridi, okanye inkqubo yolwelo iqulethe i-acids yokunciphisa, ityhubhu ye-825 inika i-Mo kunye ne-Cu igalelo elifunekayo ukuxhathisa i-pitting kunye nokuhlaselwa kwe-asidi. Ukuba isicelo sisiguquli sobushushu obuphezulu okanye i-pyrolysis furnace apho amaqondo obushushu esinyithi adlula i-600 ° C kwaye indawo engqongileyo yomile okanye i-oxidizing, i-800H okanye i-800HT ityhubhu lukhetho oluqhelekileyo.

Imeko yoluhlu oluphakathi lufanelwe ingqalelo: abatshintshi bobushushu kunye nobushushu benkqubo malunga ne-400-500 ° C kunye namanqanaba aphakathi kwekloridi. Ayiyiyo i-alloy impendulo apha. Isigqibo kufuneka sivule ukuba i-chloride yoxinaniso kunye nejometri yokukrazula idala i-SCC ethembekileyo okanye umngcipheko womgodi. Ukuba ewe, i-825 ye-nickel ephezulu kunye nomxholo we-molybdenum ubonelela ngomda wokhuseleko olubanzi.

I-Valve Trim kunye nezixhobo zoomatshini

Ivalve yangaphakathi ifumana ukhukuliseko-umhlwa, uhlaselo lwemingxuma kwindawo yokutywina, kwaye kwinkonzo emuncu, ukuqhekeka koxinzelelo lwesulfide. I-alloy 825 trim isetyenziswe kwi-asidi kunye nenkonzo yegesi emuncu apho ukudibanisa kwe-Mo yokuchasana nokugoba kunye ne-Ni ye-SCC ukumelana nayo. I-alloy 800 ayixhaphakanga kangako kwinkonzo yevalvu enomhlwa kodwa ibonakala kubushushu obuphezulu begesi yobushushu kunye nokusetyenziswa kwevalve yesithando somlilo.

Inqaku lokuqinisekisa: Uluhlu lwemveliso olufumanekayo kwiwebhusayithi kufuneka luqinisekiswe ngaphambi kokubonisa ukufumaneka kwe-valve trim okanye enye ngomatshini iindawo ze-Icoloy ngaphandle kwee washers. Ukuba ukunikezelwa kwangoku kwendawo kugxininiswe kwii-washers, eli candelo kufuneka lifundwe njengomxholo wesicelo kunokuba ibango lemveliso.

Itheyibhile yeSigqibo sokuKhetha: NgokuPhakathi kunye noBubushushu

Le theyibhile ilandelayo idibanisa ingqiqo yokhetho kwiimeko eziqhelekileyo kudibana nazo inxalenye ye-incoloy abathengi. Ithatha ukuba inxalenye yinto eqinileyo okanye edibeneyo (i-washer, ityhubhu, i-fitting, i-trim) kwaye inkxalabo ephambili yi-corrosion yamanzi ngaphandle kokuba kuchazwe ngenye indlela.

Umda obalulekileyo kwi-NACE MR0175: Lo mgangatho ujongana nokuchasana noxinzelelo lwe-sulfide kwaye uchaza izinto ezamkelekileyo kwinkonzo equlethe i-H₂S. Ayimiseli imida yokutyhoboza imingxuma. Izinto ezidweliswe kwi-MR0175 azizenzekeli "i-corrosion resistant" kuzo zonke iimeko ezimuncu; kuthetha ukuba izinto eziphathekayo zihlangabezana neemfuno zokumelana nokuqhekeka ngaphakathi komgangatho ochaziweyo womgangatho. Kwi-825 kwi-brine emuncu ene-chloride ephezulu, ukuchasana kwe-pitting kusaxhomekeke kumxholo we-Mo kunye nobushushu bokwenene kunye noxinzelelo lwe-chloride. Kwinkonzo emuncu ye-chloride ephezulu, ukuthotyelwa kwe-MR0175 kuyisiqalo, kungekhona uvavanyo olupheleleyo lwe-corrosion.

IiNgqwalasela zokuThenga nokuThenga

Ukusebenza nzima kunye Machining

I-alloy 825 kunye ne-800 zombini zisebenza nzima ngokukhawuleza kunezinsimbi ezingenasici ze-austenitic. Kuma-825 ngokuthe ngqo, izinga lokuqina komsebenzi lisezantsi ngandlel’ ithile kunamabakala aqhelekileyo e-austenitic angenasiphene kodwa lisephezulu ngokwentelekiso, kwaye izixhobo zokuyila kufuneka zinikwe amandla ngokwaneleyo ukubuyisela ukonyuka kwamandla esivuno ngexesha loguquko. Kwimisebenzi yobuchwephesha, ukuhlala okanye ukuhlikihla isixhobo kumphezulu kuqinisa umaleko osikiweyo kwaye kukhawulezise ukunxiba kwesixhobo. Kweye inxalenye ye-incoloy kunye nokunyamezelana okuqinileyo, okufana newasha eneemfuno zokukhanya okanye i-threaded fitting, ulandelelwano lwe-machining kunye nendlela yesixhobo kufuneka igweme ukudlula okungadingekile okusebenza phezulu.

Oku akuyiyo inkxalabo yethiyori kwiindawo ezibhityileyo. Iiwasha ezingaphantsi kwe-1.5 mm ubukhulu zinokugqwesa ngexesha lokufakwa kwesisombululo okanye unyango lokugqibela lobushushu ukuba aluxhaswanga ngokufanelekileyo. Iiwasha ezinobubanzi obukhulu zinokufuna amazinga okupholisa alawulwayo ukunqanda ukungqubana komda. Ezi ziinkcukacha zokuyila ekufuneka kuxoxwe ngazo kwinqanaba locaphulo, ezingafunyanwanga ngexesha lokuhlolwa kwenqaku lokuqala.

Umphezulu wokuGqibela kunye nesiphumo sawo ekuxhathiseni ukuMhlwa

Ukugrumba kunye nokukhula kwemingxuma kuqala kwindawo engaqhubekiyo: imikrwelo, intsimbi edityanisiweyo, i-tint yobushushu evela kwi-welding, kunye nemigangatho erhabaxa eyenziwe ngoomatshini. Kwiindawo ezingama-825 kwinkonzo yekloridi, imeko engaphezulu yokutywinwa kobuso kunye neendawo ezenziwe ngamaqhekeza zichaphazela ngqo ubomi benkonzo.

Isiphelo esenziwe ngoomatshini se-Ra ≤ 0.8 µm siqhelekile kwimigangatho eqhelekileyo ekwaziyo ukumelana nomhlwa. I-Electropolishing ukuya kwi-Ra ≤ 0.2 µm inokucaciswa kwiindawo ezibalulekileyo zokutywina kwinkonzo yekhemikhali okanye yococeko oluphezulu lwekhemikhali, apho zombini ukuxhathisa ukudleka kunye nokucoceka kufuneka. Ukuhlamba emanzini olwandle okanye inkonzo emuncu, ukususa i-tint yokushisa kunye nokuqinisekisa indawo ecocekileyo, engabonakaliyo emva komatshini kubaluleke kakhulu kunokufikelela kwi-ultra-low number ye-Ra.

Iitshekhi ezisemgangathweni kunye neziQinisekiso

Xa uthenga i inxalenye ye-incoloy, isatifikethi semathiriyeli kufuneka siqinisekiswe ngokuchasene nenombolo echaziweyo ye-UNS kunye nomgangatho osebenzayo:

• Ingxubevange 825umthombo: UNS N08825. Umbhobho kunye nombhobho unokuchazwa kwi-ASTM B423 / ASME SB423. Ibha kunye neefom ezibunjiweyo ziwela phantsi kweenkcazo ezahlukeneyo ngokuxhomekeke kwifom yemveliso. Ukuthotyelwa kwe-NACE MR0175 kufuneka kuchazwe ngokucacileyo kwisatifikethi ukuba kufuneka inkonzo emuncu.
• Ingxubevange 800: UNS N08800 (okanye i-N08810/N08811 ye800H/800HT). Imigangatho yemveliso iyahluka ngefom; isitokhwe sebha, ipleyiti, kunye neforgings nganye ine-ASTM eyahlukileyo.

Iphepha lemveliso ye-Incoloy ekhoyo ye-Incoloy yewebhusayithi ibonisa amandla okwenza iiwasha ze-Incoloy kukunyamezelana okuchaziweyo kunye nokugqitywa komphezulu. Kwezinye iifom, ezifana netyhubhu okanye izinto ezenziwe ngoomatshini, umda okhoyo wokuvelisa kufuneka uqinisekiswe ngokuthe ngqo kunokuba ucingelwe kwiphepha lewasha.

FAQ

Ngaba i-Incoloy 825 ihlala ilolona khetho lungcono kwinkonzo eyonakalisayo xa kuthelekiswa ne-800?
Hayi. I-alloy 825 iyona nto ingcono xa inkonzo ibandakanya i-chlorides, ukunciphisa i-acids, okanye igesi emuncu, kuba izongezo zayo ze-Mo kunye neCu zijolise kwezo ndlela. I-alloy 800 ifaneleka ngakumbi kwaye inoqoqosho ngakumbi kwi-oxidizing ephezulu yobushushu okanye i-carburizing environments apho i-corrosion iqhutywa bubushushu kune-chemistry yamanzi. Ukusebenzisa i-825 kwisicelo sesithando sokushisa okuphezulu kunokongeza iindleko ngaphandle kokongeza ukusebenza.

Ngaba i-Incoloy 800 washers ingasetyenziswa kwiiflange zamanzi olwandle?
Ayikhuthazwa. Amanzi olwandle enza iimeko zokuqhekeka kubuso bewasha kunye namanqanaba ekloridi akhuthaza ukugqobhoza. I-alloy 800 ayiqulathanga ngabom i-molybdenum, eyona nto iphambili yokudibanisa i-pitting resistance kwi-chloride media. Iiwasha ze-alloy 825 zibonelela ngomxholo we-Mo ofunekayo kule nkonzo.

Ithetha ukuthini imvume ye-NACE MR0175 eneneni ngenxalenye ye-Incoloy 825?
Kuthetha ukuba izinto eziphathekayo zihlangabezana neemfuno zomgangatho wokumelana nokuqhekeka kwe-sulfide yoxinzelelo kwiindawo eziqulethwe yi-H₂S ngaphakathi kwendawo echaziweyo yomgangatho. Ayikuqinisekisi ukuxhathisa kwimingxuma, ukubola kwemingxuma, okanye ukubola kobunzima ngokubanzi. Inxalenye ingaba yi-MR0175 ehambelanayo kwaye isabandezeleka kwi-high-chloride sour brine ukuba umxholo we-Mo kunye nemeko yomhlaba ayifanelekanga kwiimeko ezithile.

Ngaba i-ASTM B423 iyagquma iiwasha ze-Incoloy 825?
Inombolo ye-ASTM B423 igubungela umbhobho ongenamthungo kunye ityhubhu kwi-UNS N08825. Iiwasha kunye nezinye iifom ezingoomatshini zidla ngokuthengwa ngokuchasene nesatifikethi semathiriyeli esibonisa inombolo ye-UNS kunye nekhemistri kunomgangatho wefom yemveliso yeewasha. Isatifikethi masingqinisise i-N08825 chemistry kunye naluphi na uthotyelo olufunekayo lwe-NACE.

Kutheni ukugqitywa komphezulu kubaluleke kakhulu kwinxalenye ye-Incoloy kwinkonzo yekloridi?
Imingxuma iqala kwindawo eneziphene apho ingqwalasela yekloridi kunye nokufumaneka kweoksijini kwahluka kwimo engqongileyo yobuninzi. Umphezulu womatshini orhabaxa, i-tint yobushushu, okanye amasuntswana angaphandle afakwe ngaphakathi adala iindawo zokwaluka. Kwi-825 emanzini olwandle okanye i-sour brine, ichaza indawo ecocekileyo, egqithwe ngokufanelekileyo kwindawo yokutywinwa kunye neendawo ezijongene nokuqhekeka yindlela esebenzayo yokuxhasa ukuxhathisa kwe-alloy yendalo.

Ukutshatisa iAlloy kwiNkonzo

Ukhetho phakathi kwe-Incoloy 825 kunye ne-800 ye inxalenye ye-incoloy kufuneka ilandele eyona ndlela ibalaseleyo yokuthotywa kwemeko yendawo yenkonzo. Ukuba i-chlorides, ukunciphisa i-acids, okanye i-H₂S ikhona kwaye inxalenye iya kusebenza kwindawo enamanzi okanye emanzi, i-825's molybdenum, ithusi, kunye nomxholo we-nickel ilungisa ezo zisongelo ezithile. Ukuba isicelo sinobushushu obuphezulu be-oxidation, i-carburization, okanye inkonzo ye-furnace eyomileyo, i-800 okanye ukuhluka kwayo okunamandla aphezulu yintsapho efanelekileyo.

Ukuhlamba kunye namacandelo omatshini kwinkonzo yokubola, isigqibo sokukhetha kufuneka siphinde siphendule ngejometri ye-crevice, ukugqiba umphezulu, kunye neenkcukacha zokwenziwa kwezinto eziqinisekisa ukuba i-alloy echaziweyo yenza njengoko kujoliswe kuyo. Iwasha eqinisekisiweyo engama-825 enomphezulu ombi kakhulu inokusilela kwinkonzo yekloridi njengokuba iwasha egqitywe kakuhle engama-800 ayinakuthatha indawo ye-825 apho imolybdenum ifuneka khona.

Ukuphonononga iinkcukacha ezifumanekayo ze-Incoloy washer, kubandakanywa amabakala ezinto eziphathekayo, ukunyamezela, kunye nokukhethwa kokugqiba umphezulu, tyelela iphepha lemveliso ye-Incoloy washer. Kwinxalenye yeefomu ezingaphaya kweewasha, qinisekisa umda wokwenziwa kwangoku ngokuthe ngqo phambi kokuba uchaze.