Moo Li-valve li Sebelisang: Hohle!

08 Nov 2017 E ngotsoe ke Greg Johnson

Li-valve li ka fumanoa hoo e batlang e le kae kapa kae kajeno: malapeng a rona, tlas'a seterata, mehahong ea khoebo le libakeng tse likete tse ka har'a limela tsa motlakase le metsi, lifeme tsa pampiri, litlhōlisano, limela tsa lik'hemik'hale le lisebelisoa tse ling tsa indasteri le lisebelisoa.
Indasteri ea li-valve e hlile e na le mahetla a pharaletseng, ka likarolo tse fapaneng ho tloha kabong ea metsi ho ea ho matla a nyutlelie ho ea holimo le tlaase ho metsi le khase. E 'ngoe le e' ngoe ea liindasteri tsena tsa basebelisi ba ho qetela e sebelisa mefuta e meng ea motheo ea li-valve; leha ho le joalo, lintlha tsa kaho le thepa hangata li fapane haholo. Mohlala ke ona:

METSI SEBETSA
Lefatšeng la kabo ea metsi, likhatello li batla li le tlase ka linako tsohle le mocheso o le teng. Lintlha tseo tse peli tsa ts'ebeliso li lumella palo ea likarolo tsa moralo oa li-valve tse neng li ke ke tsa fumanoa lisebelisoa tse phephetsoang joalo ka li-valve tsa mocheso o phahameng oa mocheso. Thempereichara ea tikoloho ea litšebeletso tsa metsi e lumella tšebeliso ea li-elastomer le litiiso tsa rabara tse sa lokelang libakeng tse ling. Lisebelisoa tsena tse bonolo li lumella li-valve tsa metsi hore li hlomeletsoe ho koala li-drop ka thata.

Ntho e 'ngoe e nahanang ka li-valve tsa tšebeletso ea metsi ke khetho ea thepa ea kaho. Li-cast le ductile irons li sebelisoa haholo lits'ebetsong tsa metsi, haholo-holo melaleng e meholo e ka ntle ea bophara. Mehala e menyenyane haholo e ka ts'oaroa hantle ka lisebelisoa tsa li-valve tsa boronse.

Khatello eo li-valve tse ngata tsa metsi li e bonang hangata li ka tlase ho 200 psi. Sena se bolela hore ha ho hlokahale hore ho be le meralo e teteaneng e nang le marako a matla. Ha ho se ho boletsoe, ho na le maemo ao li-valve tsa metsi li hahiloeng ho sebetsana le likhatello tse phahameng, ho fihlela ho 300 psi. Hangata lisebelisoa tsena li holim'a likotopo tse telele tse haufi le mohloli oa khatello. Ka linako tse ling li-valve tsa metsi tse nang le khatello e phahameng le tsona li fumaneha libakeng tsa khatello e phahameng ka ho fetisisa letamong le lelelele.

Mokhatlo oa American Water Works Association (AWWA) o fane ka litlhaloso tse akaretsang mefuta e mengata e fapaneng ea li-valve le li-actuator tse sebelisoang lits'ebetsong tsa metsi.

METLISI
Lehlakore le leholo la metsi a hloekileng a nooang a kenang setsing kapa mohahong ke metsi a litšila kapa phallo ea likhoerekhoere. Mehala ena e bokella mokelikeli oohle oa litšila le lintho tse tiileng ebe o li lebisa setsing sa ho hloekisa likhoerekhoere. Limela tsena tsa kalafo li na le liphaephe tse ngata tse tlase tsa khatello le li-valve ho etsa "mosebetsi oa tsona o litšila." Litlhoko tsa li-valve tsa metsi a litšila maemong a mangata li bonolo haholo ho feta litlhoko tsa tšebeletso ea metsi a hloekileng. Heke ea tšepe le li-valve tsa ho hlahloba ke likhetho tse tsebahalang haholo bakeng sa mofuta ona oa ts'ebeletso. Li-valve tse tloaelehileng tšebeletsong ena li hahiloe ho latela litlhaloso tsa AWWA.

MATLA MACHABA
Boholo ba matla a motlakase a hlahisoang United States a hlahisoa ka limela tsa mouoane ho sebelisa mafura a mafura le li-turbine tsa lebelo le phahameng. Ho epolla morao sekoahelo sa setsi sa motlakase sa sejoale-joale ho tla fana ka pono ea liphaephe tse nang le khatello e phahameng ea mocheso o phahameng. Mehala ena ea mantlha ke ea bohlokoa ka ho fetisisa tšebetsong ea ho fehla matla a mouoane.

Li-valve tsa heke li lula e le khetho e ka sehloohong bakeng sa lisebelisoa tsa motlakase ho / ho tima, le hoja morero o khethehileng, li-valve tsa globe tsa Y-pattern li boetse li fumanoa. Li-valve tsa bolo ea boemo bo holimo, tse sebetsang ka thata li ntse li tuma ke baqapi ba lipolante tse fehlang motlakase 'me li ntse li tsoela pele ho kena lefatšeng lena leo pele le neng le atile li-valve.

Metallurgy e bohlokoa bakeng sa li-valve ts'ebelisong ea matla, haholo-holo tse sebetsang maemong a phahameng kapa a phahameng ka ho fetesisa a khatello le mocheso. F91, F92, C12A, hammoho le li-alloys tse 'maloa tsa Inconel le tšepe e sa hloekang li sebelisoa hangata lifemeng tsa kajeno tsa motlakase. Lihlopha tsa khatello li kenyelletsa 1500, 2500 le maemong a mang 4500. Sebopeho sa modulating sa lisebelisoa tsa matla a holimo (tse sebetsang feela ha ho hlokahala) li boetse li beha khatello e kholo ho li-valve le liphaephe, tse hlokang meralo e matla ho sebetsana le motsoako o feteletseng oa libaesekele, mocheso le khatello.
Ntle le li-valve tse ka sehloohong tsa mouoane, limela tsa motlakase li na le liphaephe tse tlatselletsang, tse nang le liheke tse ngata, globe, cheke, serurubele le li-valve tsa bolo.

Litsi tsa matla a nyutlelie li sebetsa ho latela molao-motheo o tšoanang oa mouoane/lebelo le phahameng. Phapang ea mantlha ke hore setsing sa ho fehla matla a nyutlelie, mouoane o etsoa ke mocheso o tsoang tšebetsong ea ho fission. Li-valve tsa semela sa matla a nyutlelie li tšoana le bo-motsoala ba bona ba matlafalitsoeng ka mesaletsa ea lintho tsa khale, ntle le leloko la bona le tlhokahalo e eketsehileng ea ho tšepahala ka ho feletseng. Li-valve tsa nyutlelie li entsoe ka maemo a holimo haholo, 'me litokomane tse tšoanelehang le tsa tlhahlobo li tlatsa makholo a maqephe.

TLHALOSO EA OLI LE GASE
Liliba tsa oli le khase le lisebelisoa tsa tlhahiso ke basebelisi ba boima ba li-valve, ho kenyelletsa le li-valve tse ngata tse boima. Le hoja ho ke ke ha hlola ho e-ba bonolo hore oli e hlatsellang sebaka sa limithara tse makholo moeeng e be teng, setšoantšo sena se bontša khatello e ka bang teng ka tlas'a lefatše le khase. Ke ka lebaka leo lihlooho tsa liliba kapa lifate tsa Keresemese li behoang ka holim'a phala e telele ea seliba. Likopano tsena, ka motsoako oa tsona oa li-valve le lisebelisoa tse khethehileng, li etselitsoe ho sebetsana le likhatello tse ka holimo ho 10,000 psi. Le hoja e sa fumanehe ka seoelo lilibeng tse chekiloeng mobung matsatsing ana, likhatello tse phahameng haholo hangata li fumanoa lilibeng tse tebileng tsa maoatle.

Moralo oa lisebelisoa tsa Wellhead o koahetsoe ke lintlha tsa API tse kang 6A, Specification for Wellhead le Thepa ea Sefate sa Keresemese. Li-valve tse koahetsoeng ka 6A li etselitsoe likhatello tse phahameng haholo empa mocheso o itekanetseng. Lifate tse ngata tsa Keresemese li na le li-valve tsa heke le li-valve tse khethehileng tsa globe tse bitsoang chokes. Lik'hemik'hale li sebelisetsoa ho laola ho phalla ho tsoa selibeng.

Ntle le liliba ka botsona, lisebelisoa tse ngata tse tlatselletsang li na le sebaka sa oli kapa sa khase. Lisebelisoa tsa ho lokisa oli kapa khase esale pele li hloka li-valve tse ngata. Hangata li-valve tsena ke tšepe ea carbon e lekantsoeng bakeng sa lihlopha tse tlaase.

Ka linako tse ling, mokelikeli o senyang haholo—hydrogen sulfide—o ba teng molatsoaneng o tala oa petroleum. Thepa ena, eo hape e bitsoang khase e bolila, e ka bolaea. Ho hlola mathata a khase e bolila, lisebelisoa tse khethehileng kapa mekhoa ea ho lokisa thepa ho latela litlhaloso tsa NACE International MR0175 e tlameha ho lateloa.

TS'ELISO MOFANE
Mekhoa ea liphaephe bakeng sa lisebelisoa tsa oli ea offshore le lisebelisoa tsa tlhahiso li na le li-valve tse ngata tse hahiloeng ka litlhaloso tse ngata tse fapaneng ho sebetsana le mathata a mangata a ho laola phallo. Mehaho ena e boetse e na le li-loops tse fapaneng tsa tsamaiso ea taolo le lisebelisoa tsa ho imolla khatello.

Bakeng sa lisebelisoa tsa tlhahiso ea oli, pelo ea arterial ke sistimi ea 'nete ea ho khutlisa oli kapa khase. Le hoja e se kamehla sethaleng ka boeona, mekhoa e mengata ea tlhahiso e sebelisa lifate tsa Keresemese le lisebelisoa tsa liphaephe tse sebetsang ka botebo bo tebileng ba maoto a 10,000 kapa ho feta. Thepa ena ea tlhahiso e hahiloe ho latela litekanyetso tse ngata tse nepahetseng tsa American Petroleum Institute (API) 'me ho buuoa ka mekhoa e mengata e khothalelitsoeng ea API (RPs).

Litaleng tse ngata tse kholo tsa oli, lits'ebetso tse eketsehileng li sebelisoa ho mokelikeli o tala o tsoang selibeng. Tsena li kenyelletsa ho arola metsi ho li-hydrocarbon le ho arola likhase le likhase tsa tlhaho ho tsoa mokelikeli. Lisebelisoa tsena tsa liphaephe tsa sefate sa Keresemese ka kakaretso li hahiloe ho American Society of Mechanical Engineers B31.3 li-piping codes tse nang le li-valve tse entsoeng ho latela litlhaloso tsa li-valve tsa API tse kang API 594, API 600, API 602, API 608 le API 609.

Tse ling tsa litsamaiso tsena li kanna tsa ba le heke ea API 6D, bolo le li-valve tsa ho hlahloba. Kaha liphaephe leha e le life tse sethaleng kapa sekepe sa ho phunya li ka hare ho setsi, litlhoko tse tiileng tsa ho sebelisa li-valve tsa API 6D bakeng sa liphaephe ha li sebetse. Le hoja mefuta e mengata ea li-valve e sebelisoa mekhoeng ena ea liphaephe, mofuta oa khetho ea li-valve ke valve ea bolo.

LIPHAPHAPE
Le hoja liphaephe tse ngata li patehile hore li se ke tsa bonoa, boteng ba tsona hangata bo bonahala. Matšoao a manyenyane a bolelang "peipi ea peterole" ke pontšo e 'ngoe e totobetseng ea boteng ba lipeipi tsa lipalangoang tse tsamaeang ka tlas'a lefatše. Liphaephe tsena li na le li-valve tse ngata tsa bohlokoa ka bolelele ba tsona. Li-valve tsa ho koala liphaephe tsa maemo a tšohanyetso li fumanoa ka linako tse itseng ho ea ka litekanyetso, melao le melao. Li-valve tsena li fana ka tšebeletso ea bohlokoa ea ho arola karolo e itseng ea lipeipi haeba e lutla kapa ha ho hlokahala hore ho hlokomeloe.

Ho boetse ho hasane haufi le tsela ea lipeipi ho na le lisebelisoa moo mohala o hlahang fatše le mokhoa oa ho kena oa mohala o fumanehang. Liteishene tsena ke lehae la lisebelisoa tsa ho qala "kolobe", tse nang le lisebelisoa tse kentsoeng liphaepheng ho hlahloba kapa ho hloekisa mohala. Hangata liteishene tsena tsa likolobe li na le li-valve tse 'maloa, ebang ke mefuta ea heke kapa ea bolo. Li-valve tsohle tse tsamaisong ea lipeipi li tlameha ho ba kou e felletseng (ho buloa ka botlalo) ho lumella likolobe hore li fete.

Liphaephe li boetse li hloka matla ho loantša khohlano ea lipeipi le ho boloka khatello le phallo ea mohala. Li-compressor kapa liteishene tsa ho pompa tse shebahalang eka ke mefuta e nyane ea semela sa ts'ebetso ntle le litora tse telele tse phunyehang li sebelisoa. Liteishene tsena ke lehae la li-valve tse ngata tsa heke, bolo le cheke.
Liphaephe ka botsona li entsoe ho latela litekanyetso le likhoutu tse fapaneng, ha li-valve tsa lipeipi li latela API 6D Pipeline Valves.
Ho boetse ho na le liphaephe tse nyane tse fepang matlo le meaho ea khoebo. Mehala ena e fana ka metsi le khase 'me e lebeloa ke li-valve tsa shutoff.
Limasepala tse kholo, haholo-holo karolong e ka leboea ea United States, li fana ka mouoane bakeng sa litlhoko tsa ho futhumatsa tsa bareki ba khoebo. Mehala ena ea phepelo ea mouoane e na le li-valve tse fapaneng ho laola le ho laola phepelo ea mouoane. Leha mokelikeli o le mouoane, likhatello le mocheso li tlase ho feta tse fumanoang ho fehlang mouoane oa setsi sa motlakase. Ho sebelisoa mefuta e fapaneng ea li-valve tšebeletsong ena, le hoja valve ea plug e hlomphehang e ntse e le khetho e tsebahalang.

KHAHLISO LE PETROCHEMICAL
Li-valve tsa ho hloekisa li na le tšebeliso e ngata ea li-valve tsa indasteri ho feta karolo efe kapa efe ea li-valve. Libaka tsa ho hloekisa ke lehae la maro a senyang 'me maemong a mang, mocheso o phahameng.
Lintlha tsena li laola hore na li-valve li hahoa joang ho latela litlhaloso tsa moralo oa li-valve tsa API tse kang API 600 (li-valve tsa heke), API 608 (li-valve tsa bolo) le API 594 (li-valve tsa hlahloba). Ka lebaka la ts'ebeletso e thata eo boholo ba li-valve tsena li kopanang le eona, hangata ho hlokahala tumello e eketsehileng ea kutu. Tumello ena e bonahala ka botenya bo boholo ba marako bo boletsoeng litokomaneng tsa moralo oa API.

Hoo e batlang e le mofuta o mong le o mong oa li-valve tse kholo o ka fumanoa ka bongata setsing se tloaelehileng sa tlhoekiso. Valofo ea heke e fumanehang hohle e ntse e le morena oa leralleng le nang le baahi ba bangata ka ho fetisisa, empa li-valve tsa quarter-turn li nka karolo e kholo ea karolo ea tsona ea 'maraka. Lihlahisoa tsa kotara tse atlehileng indastering ena (eo le eona e kileng ea laoloa ke lihlahisoa tsa linear) li kenyelletsa tšebetso e phahameng ea li-valve tsa serurubele sa triple offset le li-valve tsa bolo tse lutseng ka tšepe.

Li-valve tse tloaelehileng tsa heke, li-globe le li-check li ntse li fumanoa ka bongata, 'me ka lebaka la pelo e ntle ea moralo oa tsona le moruo oa tlhahiso, li ke ke tsa nyamela haufinyane.
Litekanyetso tsa khatello bakeng sa li-valve tsa ho hloekisa li tsamaisa papali ho tloha ho Sehlopha sa 150 ho ea ho Sehlopha sa 1500, 'me Sehlopha sa 300 se tsebahala haholo.
Litšepe tse sa bonahaleng tsa k'habone, joalo ka grade WCB (cast) le A-105 (forged) ke lisebelisoa tse tsebahalang haholo tse boletsoeng le tse sebelisoang li-valve bakeng sa ts'ebeletso ea tlhoekiso. Lisebelisoa tse ngata tsa ts'ebetso ea ho hloekisoa li sutumelletsa moeli oa mocheso o holimo oa litšepe tsa carbon tse hlakileng, 'me li-alloys tsa mocheso o phahameng li hlalositsoe bakeng sa lits'ebetso tsena. Tse tummeng ka ho fetisisa ho tsena ke litšepe tsa chrome / moly tse kang 1-1 / 4% Cr, 2-1 / 4% Cr, 5% Cr le 9% Cr. Litšepe tse sa hloekang le li-alloys tse phahameng tsa nickel li boetse li sebelisoa mekhoeng e meng e thata ea ho hloekisa.

K'hemik'hale
Indasteri ea lik'hemik'hale ke mosebelisi e moholo oa li-valve tsa mefuta eohle le thepa. Ho tloha ho limela tse nyane ho isa litsing tse kholo tsa petrochemical tse fumanehang Koung ea Gulf, li-valve ke karolo e kholo ea lisebelisoa tsa lipeipi tsa lik'hemik'hale.

Likopo tse ngata lits'ebetsong tsa lik'hemik'hale li tlase khatellong ho feta mekhoa e mengata ea ho hloekisa le ho hlahisa matla. Lihlopha tsa khatello tse tummeng ka ho fetisisa bakeng sa li-valve tsa limela tsa lik'hemik'hale le liphaephe ke Lihlopha tsa 150 le 300. Limela tsa lik'hemik'hale hape e bile tsona mokhanni o moholo oa karolo ea 'maraka eo li-valve tsa bolo li loanneng le li-valve tsa linear lilemong tse 40 tse fetileng. Valofo ea bolo e lutseng hantle, e nang le zero-leakage shutoff, e loketse hantle lits'ebetso tse ngata tsa semela sa lik'hemik'hale. Boholo bo kopaneng ba valve ea bolo ke karolo e tsebahalang hape.
Ho ntse ho e-na le limela tse ling tsa lik'hemik'hale le mekhoa ea limela moo li-valve tsa linear li ratoang. Maemong ana, li-valve tse ratoang tse entsoeng ka API 603, tse nang le marako a mosesaane le boima bo bobebe, hangata ke heke kapa li-valve tsa lefats'e tse khethiloeng. Taolo ea lik'hemik'hale tse ling e boetse e finyelloa ka katleho ka diaphragm kapa pinch valves.
Ka lebaka la ho senya ha lik'hemik'hale tse ngata le mekhoa ea ho etsa lik'hemik'hale, khetho ea thepa e bohlokoa. Thepa ea defacto ke mofuta oa 316/316L oa tšepe e sa hloekang ea austenitic. Sesebediswa sena se sebetsa hantle ho thibela kutu ho tswa ho maro a mangata ka dinako tse ding a mabe.

Bakeng sa lisebelisoa tse ling tse thata tse senyang, ho hlokahala tšireletso e eketsehileng. Likarolo tse ling tse phahameng tsa ts'ebetso ea austenitic tšepe e sa hloekang, joalo ka 317, 347 le 321 hangata li khethoa maemong ana. Li-alloys tse ling tse sebelisoang nako le nako ho laola maro a lik'hemik'hale li kenyelletsa Monel, Alloy 20, Inconel le 17-4 PH.

KAROHANO LNG LE GASE
Ka bobeli khase ea tlhaho ea metsi (LNG) le lits'ebetso tse hlokahalang bakeng sa karohano ea khase li itšetlehile ka liphaephe tse pharalletseng. Lisebelisoa tsena li hloka li-valve tse ka sebetsang ka mocheso o tlase haholo oa cryogenic. Indasteri ea LNG, e ntseng e hola ka potlako United States, e ntse e tsoela pele ho batla ho ntlafatsa le ho ntlafatsa ts'ebetso ea ho ntša mokelikeli oa khase. Ho fihlela sena, liphaephe le li-valve li se li le kholoanyane mme litlhoko tsa khatello li phahamisitsoe.

Boemo bona bo hloka hore bahlahisi ba li-valve ba etse meralo ho fihlela maemo a thata. Li-valve tsa "quarter-turn" le li-valve tsa serurubele li ratoa haholo bakeng sa ts'ebeletso ea LNG, 'me 316ss [stainless steel] e leng thepa e tsebahalang haholo. ANSI Class 600 ke siling e tloaelehileng ea khatello bakeng sa lits'ebetso tse ngata tsa LNG. Le hoja lihlahisoa tsa kotara e le mefuta e tsebahalang haholo ea li-valve, heke, globe le li-valve tsa ho hlahloba li ka fumanoa le limela.

Ts'ebeletso ea karohano ea khase e kenyelletsa ho arola khase ka likarolo tsa eona tsa mantlha. Ka mohlala, mekhoa ea karohano ea moea e hlahisa naetrojene, oksijene, helium le likhase tse ling tsa trace. Boemo bo tlase haholo ba mocheso oa mokhoa ona o bolela hore li-valve tse ngata tsa cryogenic lia hlokahala.

Ka bobeli LNG le limela tsa karohano ea khase li na le li-valve tsa mocheso o tlase tse lokelang ho lula li sebetsa maemong ana a cryogenic. Sena se bolela hore mokhoa oa ho paka li-valve o tlameha ho phahamisoa hole le mokelikeli o tlase oa mocheso ka tšebeliso ea khase kapa kholomo e fokotsang. Karolo ena ea khase e thibela mokelikeli hore o se ke oa etsa leqhoa ho potoloha sebaka seo ho pakoang ho sona, e leng se neng se tla thibela lehlaka la valve hore le se ke la reteleha kapa la phahama.

MOAHO MOKHOEBO
Mehaho ea khoebo e re pota-potile empa ntle le haeba re ela hloko ha e ntse e hahuoa, ha re tsebe letho ka methapo e mengata ea mokelikeli e patiloeng ka har’a marako a eona a masonry, khalase le tšepe.

Ntho e tloaelehileng hoo e batlang e le mohahong o mong le o mong ke metsi. Mehaho ena kaofela e na le mefuta e fapaneng ea liphaephe tse nang le metsoako e mengata ea motsoako oa hydrogen / oksijene ka mokhoa oa metsi a nooang, metsi a litšila, metsi a chesang, metsi a bohlooho le tšireletso ea mollo.

Ho latela pono ea ho pholoha ha moaho, lits'ebetso tsa mollo ke tsa bohlokoa haholo. Tšireletso ea mollo mehahong e batla e feptjoa hohle le ho tlala metsi a hloekileng. E le hore litsamaiso tsa metsi a mollo li atlehe, li tlameha ho tšepahala, li be le khatello e lekaneng 'me li be teng hamonate ho pholletsa le mohaho. Litsamaiso tsena li etselitsoe ho fana ka matla nakong ea mollo.
Mehaho e phahameng e hloka ts'ebeletso e ts'oanang ea khatello ea metsi mekatong e ka holimo joalo ka ha mekato e ka tlase e tlameha ho sebelisoa lipompo tsa khatello e phahameng le liphaephe ho nyolla metsi. Hangata liphaephe ke tsa Sehlopha sa 300 kapa sa 600, ho itšetlehile ka bophahamo ba mohaho. Mefuta eohle ea li-valve e sebelisoa lits'ebetsong tsena; leha ho le joalo, meralo ea li-valve e tlameha ho amoheloa ke Underwriters Laboratories kapa Factory Mutual bakeng sa ts'ebeletso ea mantlha ea mollo.

Lihlopha tse tšoanang le mefuta ea li-valve tse sebelisetsoang li-valve tsa tšebeletso ea mollo li sebelisoa bakeng sa kabo ea metsi a nooang, le hoja mokhoa oa tumello o se o tiileng.
Sistimi ea moea ea khoebo e fumanehang meahong e meholo ea khoebo joalo ka meaho ea liofisi, lihotele le lipetlele hangata li bohareng. Li na le yuniti e kholo ea chiller kapa boiler ho pholile kapa mokelikeli oa mocheso o sebelisetsoang ho fetisa mohatsela kapa mocheso o phahameng. Lisebelisoa tsena hangata li tlameha ho sebetsana le lihatsetsi tse kang R-134a, hydro-fluorocarbon, kapa ha ho na le lisebelisoa tse kholo tsa ho futhumatsa, mouoane. Ka lebaka la boholo bo kopaneng ba li-valve tsa serurubele le bolo, mefuta ena e se e tumme haholo lits'ebetsong tsa HVAC tsa chiller.

Ka lehlakoreng la mouoane, li-valve tse ling tsa kotara li se li kenelletse ho sebelisoa, leha ho le joalo baenjiniere ba bangata ba lipeipi ba ntse ba itšetlehile ka li-linear heke le li-valve tsa globe, haholo-holo haeba liphaephe li hloka lipheletso tsa butt-weld. Bakeng sa lisebelisoa tsena tse itekanetseng tsa mouoane, tšepe e nkile sebaka sa tšepe ka lebaka la ho cheseha ha tšepe.

Lisebelisoa tse ling tsa ho futhumatsa li sebelisa metsi a chesang ho e-na le mouoane e le mokelikeli o fetisang. Lisebelisoa tsena li sebelisoa hantle ka li-valve tsa boronse kapa tsa tšepe. Li-valve tsa li-quarter-turn resilient-seated ball le serurubele li tumme haholo, leha ho ntse ho sebelisoa meralo e meng ea mela.

TS'ELISO
Le hoja bopaki ba li-valve tse boletsoeng sehloohong sena bo ka 'na ba se ke ba bonahala nakong ea leeto la ho ea Starbucks kapa ntlong ea nkhono, li-valve tse ling tsa bohlokoa haholo li lula li le haufi. Ho na le li-valve ka har’a enjene ea koloi e sebelisoang ho fihla libakeng tseo tse kang tse ka har’a carburetor tse laolang ho phalla ha mafura enjeneng le tse ka enjeneng tse laolang ho phalla ha peterole ho kena ka har’a lipiston le ho tsoa hape. 'Me haeba li-valve tseo li se haufi ka ho lekaneng bophelong ba rona ba letsatsi le letsatsi, nahana ka 'nete ea hore lipelo tsa rona li otla khafetsa ka lisebelisoa tse' nè tsa bohlokoa tsa ho laola phallo.

Ona ke mohlala o mong feela oa 'nete ea hore: li-valve li teng hohle. VM
Karolo ea II ea sengoloa sena e akaretsa liindasteri tse ling moo ho sebelisoang li-valve. E-ea ho www.valvemagazine.com ho bala ka pulp & paper, lisebelisoa tsa metsing, matamo le matla a fehlang metsi, letsatsi, tšepe le tšepe, sebaka sa sefofane, mocheso oa mocheso, le ho ritela le ho etsa distilling.

GREG JOHNSON ke mopresidente oa United Valve (www.unitedvalve.com) e Houston. Ke mohlophisi ea kenyang letsoho ho VALVE Magazine, molula-setulo oa nakong e fetileng oa Lekhotla la Tokiso ea Li-Valve le setho sa hajoale sa boto ea VRC. Hape o sebeletsa Komiting ea Thuto le Koetliso ea VMA, ke motlatsi oa molula-setulo oa Komiti ea Likhokahano ea VMA hape ke mopresidente oa nakong e fetileng oa Mokhatlo oa Maemo a Baetsi.