Lokhu kubuka konke kunikeza izincomo zokuklama okuphephile kwamasistimu amapayipi okusabalalisa i-hydrogen.
IHydrojeni iwuketshezi oluguquguqukayo kakhulu oluvame ukuvuza.Kuyinhlanganisela eyingozi kakhulu futhi ebulalayo yokuthambekela, uketshezi oluguquguqukayo okunzima ukululawula.Lawa amathrendi okufanele acatshangelwe lapho ukhetha izinto zokwakha, ama-gaskets kanye nezimpawu, kanye nezici zokuklama zezinhlelo ezinjalo.Lezi zihloko ezimayelana nokusatshalaliswa kwe-H2 enegesi yizo okugxilwe kuzo kule ngxoxo, hhayi ukukhiqizwa kwe-H2, uketshezi H2, noma uketshezi H2 (bona ibha eseceleni kwesokudla).
Nawa amaphuzu abalulekile ambalwa angakusiza uqonde ingxube ye-hydrogen ne-H2-air.I-Hydrogen ishisa ngezindlela ezimbili: i-deflagration nokuqhuma.
deflagration.I-Deflagration iyindlela evamile yokuvutha lapho amalangabi ehamba ngengxube ngesivinini esingaphansi.Lokhu kwenzeka, isibonelo, lapho ifu lamahhala lengxube ye-hydrogen-air lithungelwa umthombo omncane wokuthungela.Kulokhu, ilangabi lizohamba ngesivinini esingamamitha ayishumi kuya kwamakhulu amaningana ngomzuzwana.Ukunwetshwa okusheshayo kwegesi eshisayo kudala amaza okucindezela amandla awo alingana nosayizi wamafu.Kwezinye izimo, amandla we-shock wave anganele ukulimaza izakhiwo zesakhiwo nezinye izinto ezisendleleni yawo futhi abangele ukulimala.
qhuma.Lapho liqhuma, amalangabi namagagasi athusayo ayehamba kule ngxube ngesivinini esikhulu.Isilinganiso sokucindezela ku-wave detonation sikhulu kakhulu kune-detonation.Ngenxa yokwanda kwamandla, ukuqhuma kuyingozi kakhulu kubantu, izakhiwo kanye nezinto eziseduze.Ukwehliswa komlilo okuvamile kubangela ukuqhuma lapho kuthungelwa endaweni evalekile.Endaweni encane kangaka, ukuthungela kungabangelwa inani elincane lamandla.Kodwa ukuze kuqhunyiswe ingxube ye-hydrogen-air endaweni engenamkhawulo, umthombo onamandla kakhulu wokuthungela uyadingeka.
Isilinganiso sokucindezela kulo lonke igagasi lokuqhunyiswa engxubeni ye-hydrogen-air singaba ngu-20. Emkhathini womoya, isilinganiso esingu-20 singama-psi angu-300.Lapho leli gagasi lokucindezela lishayisana nento emile, isilinganiso sokucindezela siyenyuka sibe ngu-40-60.Lokhu kungenxa yokuvezwa kwegagasi lokucindezela elisuka kusithiyo esimile.
Ukuthambekela kokuvuza.Ngenxa ye-viscosity yayo ephansi kanye nesisindo esiphansi samangqamuzana, igesi ye-H2 inomkhuba ophezulu wokuvuza futhi ngisho nokungena noma ukungena ezintweni ezihlukahlukene.
I-Hydrogen ilula izikhathi ezingu-8 kunegesi yemvelo, ilula izikhathi ezingu-14 kunomoya, ilula izikhathi ezingu-22 kune-propane futhi ilula izikhathi ezingu-57 kunomoya kaphethiloli.Lokhu kusho ukuthi uma ifakwe ngaphandle, igesi ye-H2 izokhuphuka ngokushesha futhi ihlakazeke, inciphise noma yiziphi izimpawu zokuvuza nokuvuza.Kodwa kungaba inkemba esika nhlangothi zombili.Ukuqhuma kungase kwenzeke uma ukushisela kuzokwenziwa ekufakweni kwangaphandle ngenhla noma ekunciphiseni umoya kokuvuza kwe-H2 ngaphandle kocwaningo lokuthola ukuvuza ngaphambi kokushisela.Esikhaleni esivalekile, igesi ye-H2 ingakhuphuka futhi inqwabelane isuka ophahleni yehle, isimo esiyivumela ukuthi yakheke ibe ngamavolumu amakhulu ngaphambi kokuba ibe maningi amathuba okuthi ihlangane nemithombo yokuthungela eduze nomhlabathi.
Umlilo wengozi.Ukuzithungela kuyisenzo lapho ingxube yamagesi noma umhwamuko ivutha ngokuzenzekelayo ngaphandle komthombo wangaphandle wokuthungela.Kwaziwa nangokuthi “ukuvutha okuzenzakalelayo” noma “ukuvutha okuzenzakalelayo”.Ukuzishisa kuncike ekushiseni, hhayi ekucindezelweni.
Izinga lokushisa elizenzakalelayo liyizinga lokushisa elincane lapho uphethiloli uzovutha khona ngokuzenzakalelayo ngaphambi kokuthungela lapho ungekho umthombo wangaphandle wokuthungela lapho uthintana nomoya noma i-ejenti eyenza i-oxidizing.Ukushisa okuzenzakalelayo kwempushana eyodwa yizinga lokushisa lapho livutha khona ngokuzenzakalelayo lapho kungekho i-oxidizing agent.Izinga lokushisa elizithungelayo legesi H2 emoyeni lingu-585°C.
Amandla okuthungela amandla adingekayo ukuze kuqalwe ukusakazeka kwelangabi ngengxube evuthayo.Amandla amancane okuthungela amandla amancane adingekayo ukuthungela ingxube ethile evuthayo ezingeni elithile lokushisa nokucindezela.Amandla amancane okuthungela inhlansi yegesi i-H2 ku-atm engu-1 yomoya = 1.9 × 10–8 BTU (0.02 mJ).
Imikhawulo yeziqhumane ubukhulu nobuncane bokugxila komhwamuko, inkungu noma izintuli ezisemoyeni noma komoyampilo lapho ukuqhuma kwenzeka khona.Ubukhulu kanye nejiyomethri yendawo ezungezile, kanye nokugxila kukaphethiloli, kulawula imingcele."Umkhawulo wokuqhuma" ngezinye izikhathi usetshenziswa njengegama elifanayo elithi "umkhawulo wokuqhuma".
Imikhawulo yokuqhuma kwezingxube ze-H2 emoyeni ingu-18.3 vol.% (umkhawulo ophansi) kanye no-59 vol.% (umkhawulo ongaphezulu).
Lapho uklama amasistimu amapayipi (Umfanekiso 1), isinyathelo sokuqala ukunquma izinto zokwakha ezidingekayo kuhlobo ngalunye loketshezi.Futhi uketshezi ngalunye luzohlukaniswa ngokuhambisana nesigaba se-ASME B31.3.300(b)(1) ithi, “Umnikazi futhi unesibopho sokunquma isigaba D, M, ingcindezi ephezulu, nokuhlanzeka kwamapayipi, futhi anqume ukuthi kufanele kusetshenziswe isistimu ethile yekhwalithi yini.”
Ukuhlukaniswa koketshezi kuchaza izinga lokuhlola kanye nohlobo lokuhlola oludingekayo, kanye nezinye izidingo eziningi ezisekelwe esigabeni soketshezi.Isibopho somnikazi salokhu ngokuvamile siwela kumnyango wobunjiniyela womnikazi noma unjiniyela ohlinzekwe ngaphandle.
Nakuba Ikhodi Yepayipi Yenqubo ye-B31.3 ingamtsheli umnikazi ukuthi iyiphi impahla okufanele ayisebenzisele uketshezi oluthile, inikeza isiqondiso samandla, ukujiya, kanye nezidingo zokuxhuma izinto ezibonakalayo.Kukhona futhi izitatimende ezimbili esethulweni sekhodi ezisho ngokucacile:
Futhi andise endimeni yokuqala engenhla, isigaba B31.3.300(b)(1) futhi ithi: “Umnikazi wokufakwa kwamapayipi unomthwalo wemfanelo kuphela wokuthobela le Khodi kanye nokusungula umklamo, ukwakhiwa, ukuhlolwa, ukuhlolwa, kanye nezidingo zokuhlola ezilawula konke ukuphatha uketshezi noma inqubo ipayipi eliyingxenye yalo.Ukufakwa.”Ngakho-ke, ngemva kokubeka imithetho eyisisekelo yesibopho nezidingo zokuchaza izigaba zesevisi yoketshezi, ake sibone ukuthi igesi ye-hydrogen ingena kuphi.
Ngenxa yokuthi igesi ye-hydrogen isebenza njengoketshezi oluguquguqukayo oluvuzayo, igesi ye-hydrogen ingabhekwa njengoketshezi oluvamile noma uketshezi LweSigaba M ngaphansi kwesigaba B31.3 ngesevisi yoketshezi.Njengoba kushiwo ngenhla, ukuhlukaniswa kokuphathwa koketshezi kuyisidingo somnikazi, inqobo nje uma kuhlangabezana neziqondiso zezigaba ezikhethiwe ezichazwe ku-B31.3, isigaba 3. 300.2 Izincazelo esigabeni “Amasevisi Amanzi”.Okulandelayo yizincazelo zesevisi yoketshezi evamile kanye nesevisi yoketshezi Lwekilasi M:
“Isevisi Yoketshezi Oluvamile: Isevisi yoketshezi esebenza kumapayipi amaningi ngaphansi kwale khodi, okungukuthi ayikho ngaphansi kwemithetho yezigaba D, M, izinga lokushisa eliphezulu, umfutho ophezulu, noma ukuhlanzeka koketshezi oluphezulu.
(1) Ubuthi boketshezi bukhulu kangangokuthi ukuchayeka okukodwa esilinganisweni esincane kakhulu soketshezi olubangelwa ukuvuza kungabangela ukulimala okukhulu unomphela kulabo abadonsa umoya noma abathintana nalo, ngisho noma kuthathwa izinyathelo zokululama ngokushesha.kuthathwe
(2) Ngemva kokucabangela umklamo wamapayipi, isipiliyoni, izimo zokusebenza, nendawo, umnikazi unquma ukuthi izimfuneko zokusetshenziswa okuvamile koketshezi azanele ukunikeza ukucinana okudingekayo ukuze kuvikelwe izisebenzi ekuchayekeni.”
Encazelweni engenhla ye-M, igesi ye-hydrogen ayihlangabezani nemibandela yesigaba (1) ngoba ayithathwa njengoketshezi olunobuthi.Nokho, ngokusebenzisa isigatshana (2), Ikhodi ivumela ukuhlukaniswa kwamasistimu asebenza ngamanzi ekilasini M ngemva kokucubungula okufanele “…umklamo wamapayipi, ulwazi, izimo zokusebenza nendawo…” Umnikazi uvumela ukunqunywa kokuphathwa koketshezi olujwayelekile.Izidingo azanele ukuhlangabezana nesidingo sezinga eliphezulu lobuqotho ekwakhiweni, ekwakhiweni, ekuhlolweni, ekuhlolweni nasekuhlolweni kwezinhlelo zamapayipi egesi ye-hydrogen.
Sicela ubheke Ithebula 1 ngaphambi kokuxoxa ngokuCorrosion of Hydrogen Corrosion (HTHA)Amakhodi, izindinganiso, kanye nemithethonqubo ibalwe kuleli thebula, elihlanganisa imibhalo eyisithupha ngesihloko se-hydrogen embrittlement (HE), ukugqwala okuvamile okuhlanganisa i-HTHA.OH kungenzeka emazingeni okushisa aphansi naphezulu.Kuthathwa njengohlobo lokugqwala, kungaqalwa ngezindlela eziningi futhi kuthinte inhlobonhlobo yezinto.
I-HE inezinhlobo ezihlukahlukene, ezingahlukaniswa zibe ukuqhekeka kwe-hydrogen (HAC), i-hydrogen stress cracking (HSC), i-stress corrosion cracking (SCC), i-hydrogen corrosion cracking (HACC), i-hydrogen bubbling (HB), i-hydrogen cracking (HIC).)), ukuqhekeka kwe-hydrogen okugxile ekucindezelekeni (SOHIC), ukuqhekeka okuqhubekayo (SWC), ukuqhekeka kwe-sulfide stress (SSC), ukuqhekeka kwendawo ethambile (SZC), kanye nokushisa okuphezulu kwe-hydrogen corrosion (HTHA).
Ngendlela yayo elula, i-hydrogen embrittlement iyindlela yokucekela phansi imingcele yezinhlamvu zensimbi, okuholela ekunciphiseni kwe-ductility ngenxa yokungena kwe-athomu ye-hydrogen.Izindlela lokhu okwenzeka ngazo ziyahlukahluka futhi ngokwengxenye zichazwa ngamagama azo ahlukene, njenge-HTHA, lapho izinga lokushisa eliphakeme ngasikhathi sinye kanye ne-high pressure hydrogen idingeka ukuze i-embrittlement, kanye ne-SSC, lapho i-athomu ye-hydrogen ikhiqizwa njengamagesi avaliwe ne-hydrogen.ngenxa yokugqwala kwe-asidi, bangena emacaleni ensimbi, okungaholela ekubeni brittleness.Kodwa umphumela usuwonke uyafana nakuzo zonke izimo ze-hydrogen embrittlement ezichazwe ngenhla, lapho amandla ensimbi encishiswa ngokufinyela ngaphansi kwebanga elivumelekile lokucindezeleka, okubuye kubeke isiteji sesenzakalo esingase sibe yinhlekelele uma kubhekwa ukuntengantenga koketshezi.
Ngaphezu kokuqina kodonga nokusebenza okuhlangene komshini, kunezici ezimbili eziyinhloko okufanele zicatshangelwe lapho kukhethwa izinto zesevisi yegesi ye-H2: 1. Ukuchayeka ekushiseni okuphezulu kwe-hydrogen (HTHA) kanye 2. Ukukhathazeka okujulile mayelana nokuvuza okungase kube khona.Zombili lezi zihloko kusaxoxwa ngazo.
Ngokungafani ne-hydrogen yamangqamuzana, i-athomu ye-hydrogen ingakhula, iveze i-hydrogen emazingeni okushisa aphezulu nezingcindezi, idale isisekelo se-HTHA engaba khona.Ngaphansi kwalezi zimo, i-athomu ye-hydrogen iyakwazi ukusakazeka ibe izinto ezisetshenziswayo zamapayipi ensimbi yensimbi noma okokusebenza, lapho ihlangana nekhabhoni esixazululweni sensimbi ukwenza igesi ye-methane emingceleni yokusanhlamvu.Ayikwazanga ukuphunyuka, igesi iyakhula, idale imifantu nemifantu ezindongeni zamapayipi noma imikhumbi - lena yi-HTGA.Ungabona ngokucacile imiphumela ye-HTHA kumfanekiso 2 lapho ukuqhekeka nokuqhekeka kubonakala odongeni elingu-8″.Ingxenye yepayipi likasayizi we-nominal (NPS) ehluleka ngaphansi kwalezi zimo.
Insimbi yekhabhoni ingasetshenziselwa isevisi ye-hydrogen uma izinga lokushisa lokusebenza ligcinwa lingaphansi kuka-500°F.Njengoba kushiwo ngenhla, i-HTHA yenzeka lapho igesi ye-hydrogen ibanjwe ngomfutho ophakeme wengxenye kanye nezinga lokushisa eliphezulu.Insimbi yekhabhoni ayinconywa uma ukucindezela kwengxenye ye-hydrogen kulindeleke ukuthi ibe cishe ku-3000 psi futhi izinga lokushisa lingaphezu kuka-450°F (okuyisimo sengozi kuMfanekiso 2).
Njengoba kungabonwa esakhiweni sikaNelson esiguquliwe kuMfanekiso 3, ngokwengxenye ethathwe ku-API 941, izinga lokushisa eliphezulu linomphumela omkhulu kakhulu ekuphoqeleleni i-hydrogen.Umfutho wengxenye yegesi ye-hydrogen ungadlula u-1000 psi uma usetshenziswa nezinsimbi zekhabhoni ezisebenza emazingeni okushisa afika ku-500°F.
Umfanekiso 3. Leli shadi likaNelson eliguquliwe (lithathwe ku-API 941) lingasetshenziswa ukukhetha izinto ezifanele zesevisi ye-hydrogen emazingeni okushisa ahlukahlukene.
Emkhiwaneni.I-3 ibonisa ukukhethwa kwezinsimbi eziqinisekisiwe ukugwema ukuhlaselwa kwe-hydrogen, kuye ngezinga lokushisa lokusebenza nokucindezela ingxenye ye-hydrogen.Izinsimbi ezingenasici ze-Austenitic azizwelani ne-HTHA futhi ziyizinto ezanelisayo kuwo wonke amazinga okushisa nezingcindezi.
I-Austenitic 316/316L insimbi engagqwali iyinto esebenzayo kakhulu yokufakwa kwe-hydrogen futhi inomlando ofakazelwe.Nakuba ukwelashwa kokushisa kwe-post-weld (PWHT) kunconywa ezinsimbi zekhabhoni ukubala i-hydrogen esalayo ngesikhathi sokushisela futhi kunciphise ubulukhuni bendawo ethinteke ekushiseni (HAZ) ngemva kokushisela, akudingekile ezinsimbi ezingenasici ze-austenitic.
Imiphumela ye-thermothermal ebangelwa ukwelashwa kokushisa nokushisela ayinawo umthelela omncane kuzakhiwo zemishini zama-austenitic stainless steels.Kodwa-ke, ukusebenza okubandayo kungathuthukisa izakhiwo zemishini ye-austenitic stainless steels, njengamandla nobulukhuni.Lapho ugoba futhi wenza amapayipi avela ensimbi engagqwali ye-austenitic, izakhiwo zabo zemishini ziyashintsha, kuhlanganise nokuncipha kwepulasitiki yezinto.
Uma insimbi engagqwali ye-austenitic idinga ukwakheka okubandayo, isixazululo se-annealing (ukushisa kufika cishe ku-1045°C okulandelwa ukucisha noma ukupholisa ngokushesha) kuzobuyisela izici zomshini zezinto kumanani azo asekuqaleni.Izophinde iqede ukuhlukaniswa kwe-alloy, ukuzwela kanye nesigaba se-sigma esifinyelelwe ngemva kokusebenza okubandayo.Uma wenza isixazululo se-annealing, qaphela ukuthi ukupholisa okusheshayo kungabuyisela ingcindezi eyinsalela kokusebenza uma kungaphathwanga kahle.
Bheka amathebula GR-2.1.1-1 Piping and Tubing Assembly Specification Inkomba kanye ne-GR-2.1.1-2 Piping Material Specification Index ku-ASME B31 ukuze uthole ukukhetha kwezinto ezamukelekayo zesevisi ye-H2.amapayipi ayindawo enhle yokuqala.
Ngesisindo se-athomu esijwayelekile samayunithi we-athomu ye-athomu engu-1.008 (amu), i-hydrogen iyinto elula kakhulu futhi encane kunazo zonke kuthebula le-periodic, futhi ngenxa yalokho inokuthambekela okuphezulu kokuvuza, okunemiphumela enamandla elimazayo, ngingase ngengeze.Ngakho-ke, uhlelo lwamapayipi egesi kufanele luklanywe ngendlela ezonciphisa ukuxhunywa kohlobo lwemishini futhi kuthuthukiswe lokho kuxhumana okudingeka ngempela.
Lapho ukhawulela izindawo ezingavuza ezingase zibe khona, isistimu kufanele ishiselwe ngokugcwele, ngaphandle kokuxhunywa okune-flange emishinini, izakhi zamapayipi nezixhumi.Ukuxhumana okunemicu kufanele kugwenywe ngangokunokwenzeka, uma kungenjalo ngokuphelele.Uma ukuxhuma okufakwe imicu kungenakugwenywa nganoma yisiphi isizathu, kunconywa ukuthi uhlanganyele ngokugcwele ngaphandle kwe-thread sealant bese uvala i-weld.Uma usebenzisa ipayipi lensimbi ye-carbon, izihlanganisi zamapayipi kufanele zishiselwe ngezinqe futhi ziphathwe ukushisa okushiselwe (PWHT).Ngemuva kokushisela, amapayipi endaweni ethinteke ukushisa (HAZ) avezwa ukuhlaselwa kwe-hydrogen ngisho nasezingeni lokushisa elizungezile.Nakuba ukuhlasela kwe-hydrogen kwenzeka ngokuyinhloko emazingeni okushisa aphezulu, isigaba se-PWHT sizonciphisa ngokuphelele, uma singaqedi, lokhu kungenzeka ngisho nangaphansi kwezimo ezizungezile.
Iphuzu elibuthakathaka lesistimu ye-welded yonke uxhumano lwe-flange.Ukuqinisekisa izinga eliphezulu lokuqina ekuxhumekeni kwe-flange, ama-gaskets e-Kammprofile (umfanekiso we-4) noma olunye uhlobo lwe-gaskets kufanele lusetshenziswe.Yenziwe cishe ngendlela efanayo ngabakhiqizi abaningana, le pad iyathethelela kakhulu.Iqukethe izindandatho zensimbi yonke anamazinyo ahlanganiswe phakathi kwezinto ezithambile, ezigogekayo zokuvala.Amazinyo agxilisa umthwalo webhawodi endaweni encane ukuze anikeze ukulingana okuqinile ngokucindezeleka okuncane.Iklanywe ngendlela yokuthi ingakwazi ukunxephezela izindawo ezivulekile ze-flange ezingalingani kanye nezimo zokusebenza ezishintshayo.
Umfanekiso 4. Ama-gaskets e-Kammprofile anomgogodla wensimbi oboshwe ezinhlangothini zombili nge-filler ethambile.
Esinye isici esibalulekile ekuthembekeni kwesistimu yi-valve.Ukuvuza okuzungeze uphawu lwe-stem kanye nama-flange omzimba kuyinkinga yangempela.Ukuze uvimbele lokhu, kunconywa ukuthi ukhethe i-valve ene-bellows seal.
Sebenzisa iyintshi engu-1.Ipayipi lensimbi le-carbon steel lesikole esingu-80, esibonelweni sethu esingezansi, sinikezwe ukubekezelelana kokukhiqiza, ukugqwala nokubekezelelana kwemishini ngokuhambisana ne-ASTM A106 Gr B, ingcindezi ephezulu evumelekile yokusebenza (MAWP) ingabalwa ngezinyathelo ezimbili emazingeni okushisa afika ku-300°F (Qaphela : Isizathu sokuthi “...samazinga okushisa afika ku-300º00) yingoba i-stress ye-GTM evumela i-Asterio1 iqale i-Asterio F. izinga uma izinga lokushisa lidlula u-300ºF.(S), ngakho Isibalo (1) sidinga Lungisa amazinga okushisa angaphezu kuka-300ºF.)
Ngokubhekiselwa kufomula (1), isinyathelo sokuqala ukubala ingcindezi yokuqhuma kwethiyori yepayipi.
T = ukujiya kodonga lwamapayipi kususwa ukubekezelelwa kwemishini, ukugqwala kanye nokukhiqiza, ngamayintshi.
Ingxenye yesibili yenqubo iwukubala ingcindezi ephezulu yokusebenza evumelekile engu-Pa yepayipi ngokusebenzisa isici sokuphepha esingu-S f kumphumela P ngokuya ngesibalo (2):
Ngakho-ke, lapho usebenzisa 1″ impahla yesikole 80, ingcindezi yokuqhuma ibalwa ngale ndlela elandelayo:
I-Sf yokuphepha engu-4 ibe isisetshenziswa ngokuhambisana ne-ASME Pressure Vessel Recommendations Isigaba VIII-1 2019, Isigaba 8. UG-101 sibalwa ngale ndlela elandelayo:
Inani eliwumphumela le-MAWP lingu-810 psi.intshi isho ipayipi kuphela.Uxhumo lwe-flange noma ingxenye enezilinganiso eziphansi kakhulu ohlelweni kuzoba yisici esinqumayo ekunqumeni ingcindezi evunyelwe ohlelweni.
Ngokwe-ASME B16.5, ingcindezi yokusebenza ephezulu evumelekile yokufakwa kwe-carbon steel flange engu-150 ingu-285 psi.intshi ku -20°F kuya ku-100°F.I-Class 300 inengcindezi yokusebenza ephezulu evumelekile engu-740 psi.Lokhu kuzoba isici somkhawulo wengcindezi wesistimu ngokuya ngesibonelo sezinto ezibonakalayo ngezansi.Futhi, kuphela ekuhlolweni kwe-hydrostatic, lawa manani angadlula izikhathi eziyi-1.5.
Njengesibonelo sokucaciswa kwezinto eziyisisekelo ze-carbon steel, ukucaciswa komugqa wesevisi yegesi ye-H2 okusebenza kuzinga lokushisa elizungezile elingaphansi kwengcindezi yedizayini engu-740 psi.intshi, ingase iqukathe izimfuneko zezinto ezibonakalayo eziboniswe kuThebula 2. Okulandelayo yizinhlobo ezingase zidinge ukunakwa ukuze zifakwe encazelweni:
Ngaphandle kwamapayipi ngokwawo, kunezici eziningi ezakha isistimu yamapayipi njengezixhumi, ama-valve, okokusebenza kolayini, njll. Nakuba eziningi zalezi zakhi zizohlanganiswa emgqeni ukuze kuxoxwe ngazo ngokuningiliziwe, lokhu kuzodinga amakhasi amaningi kunalawo angahlaliswa.Lesi sihloko.