Leha ho le joaloli-valve tsa polasetikika linako tse ling li nkuoa e le sehlahisoa se ikhethileng-khetho ea pele bakeng sa batho ba etsang kapa ba ralang lihlahisoa tsa liphaephe tsa polasetiki bakeng sa lits'ebetso tsa indasteri kapa ba tlamehang ho ba le lisebelisoa tse hloekileng haholo-ke ho nka hore li-valve tsena ha li na lisebelisoa tse ngata tse akaretsang. Ha e le hantle, li-valve tsa kajeno tsa polasetiki li na le mefuta e mengata ea tšebeliso, hobane mefuta ea thepa e ntse e eketseha, 'me baqapi ba molemo ba hlokang lisebelisoa tsena ba bolela hore ho na le litsela tse ngata tsa ho sebelisa lisebelisoa tsena tse ngata.

LITŠOANTŠISO PLASTIKI

Melemo ea li-valve tsa thermoplastic li na le bophara-ho senya, lik'hemik'hale le ho hanyetsa ho senya; mabota a ka hare a boreleli; boima bo bobebe; boiketlo ba ho kenya; tebello ea bophelo bo bolelele; le litšenyehelo tse tlase tsa potoloho ea bophelo. Melemo ena e entse hore ho amoheloe li-valve tsa polasetiki ka bongata lits'ebetsong tsa khoebo le tsa indasteri tse joalo ka kabo ea metsi, kalafo ea metsi a litšila, ts'ebetso ea tšepe le lik'hemik'hale, lijo le meriana, limela tsa motlakase, lisebelisoa tsa ho hloekisa oli le li-valve tsa moPlastic li ka etsoa ka lisebelisoa tse fapaneng tse sebelisoang. ka palo ea litlhophiso. Li-valve tsa thermoplastic tse tloaelehileng haholo li entsoe ka polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene (PP), le polyvinylidene fluoride (PVDF). Li-valve tsa PVC le tsa CPVC li atisa ho kopanngoa le tsamaiso ea liphaephe ka li-socket sockets tsa solvent, kapa lipheletsong tse nang le likhoele le tse nang le flanged; athe, PP le PVDF li hloka ho kopanngoa ha likarolo tsa tsamaiso ea liphaephe, ebang ke ka mocheso-, butt- kapa electro-fusion technologies.

Li-valve tsa Thermoplastic li sebetsa hantle libakeng tse senyang, empa li na le thuso joalo ka litšebeletso tse akaretsang tsa metsi hobane ha li na lead1, ha li khone ho chesoa 'me li ke ke tsa rusa. Sistimi le li-valve tsa PVC le CPVC li lokela ho lekoa le ho netefatsoa ho NSF [National Sanitation Foundation] standard 61 bakeng sa litlamorao tsa bophelo bo botle, ho kenyeletsoa tlhokahalo e tlase ea lead bakeng sa Annex G. Ho khetha thepa e nepahetseng bakeng sa maro a senyang ho ka sebetsanoa ka ho shebana le khanyetso ea lik'hemik'hale ea moetsi. tataisa le ho utloisisa phello eo mocheso o tla ba le eona holim'a matla a thepa ea polasetiki.

Le hoja polypropylene e na le halofo ea matla a PVC le CPVC, e na le lik'hemik'hale tse ngata tse hanyetsanang le lik'hemik'hale hobane ha ho na li-solvents tse tsejoang. PP e sebetsa hantle ka har'a acetic acid le hydroxides, hape e loketse litharollo tse bobebe tsa li-acids tse ngata, alkalis, matsoai le lik'hemik'hale tse ngata tsa tlhaho.

PP e fumaneha e le thepa e mebala-bala kapa e se nang 'mala (ea tlhaho). Natural PP e senyehile haholo ke mahlaseli a ultraviolet (UV), empa metsoako e nang le "carbon black pigmentation" e fetang 2.5% e tsitsitse ka mokhoa o lekaneng oa UV.

Lisebelisoa tsa liphaephe tsa PVDF li sebelisoa mefuteng e fapaneng ea liindasteri ho tloha ho tsa meriana ho ea merafong ka lebaka la matla a PVDF, mocheso o sebetsang le ho hanyetsa lik'hemik'hale ho matsoai, li-acids tse matla, li-bases tsa dilute le lihlahisoa tse ngata tsa tlhaho. Ho fapana le PP, PVDF ha e senyehe ke khanya ea letsatsi; leha ho le joalo, polasetiki e pepesehetse mahlaseli a letsatsi 'me e ka pepesetsa mokelikeli mahlaseling a UV. Le hoja motsoako oa tlhaho, o se nang 'mala oa PVDF o le motle haholo bakeng sa ho hloeka ho phahameng, lisebelisoa tsa ka tlung, ho eketsa mmala o kang o mofubelu oa lijo ho ka lumella ho pepesehela mahlaseli a letsatsi ntle le phello e mpe mokelikeli.

Lits'ebetso tsa polasetiki li na le liphephetso tsa moralo, joalo ka kutloelo-bohloko ho mocheso le katoloso ea mocheso le ho honyela, empa lienjineri li ka khona ebile li ralile lisebelisoa tsa lipeipi tse tšoarellang nako e telele, tse bolokang chelete e ngata bakeng sa tikoloho e akaretsang le e senyang. Tlhokomelo e kholo ea moralo ke hore coefficient ea katoloso ea mocheso bakeng sa polasetiki e kholo ho feta tšepe-thermoplastic ke makhetlo a mahlano ho isa ho a tšeletseng a tšepe, mohlala.

Ha ho etsoa moralo oa liphaephe le ho nahana ka phello ea ho beoa ha li-valve le litšehetso tsa li-valve, ntho ea bohlokoa eo ho nahanoang ka eona ho thermoplastics ke bolelele ba mocheso. Matšoenyeho le matla a bakoang ke ho atolosoa ha mocheso le ho fokotseha ho ka fokotsoa kapa ho felisoa ka ho fana ka ho feto-fetoha ha mekhoa ea liphaephe ka ho fetoha khafetsa ho tataiso kapa ho kenngoa ha li-loops tsa ho atolosa. Ka ho fana ka phetoho ena ho latela tsamaiso ea liphaephe, valve ea polasetiki e ke ke ea hlokoa hore e amohele khatello ea kelello e ngata (Setšoantšo sa 1).

Kaha thermoplastics e na le bothata ba mocheso, tekanyo ea khatello ea valve e fokotseha ha mocheso o ntse o phahama. Lisebelisoa tse fapaneng tsa polasetiki li na le deration e lumellanang le mocheso o eketsehileng. Thempereichara ea metsi e ka 'na ea se ke ea e-ba oona feela mohloli oa mocheso o ka amang tekanyo ea khatello ea li-valve tsa polasetiki - mocheso o phahameng ka ntle o lokela ho ba karolo ea ho nahanisisa ka moralo. Maemong a mang, ho se etse moralo oa mocheso oa ka ntle oa liphaephe ho ka baka ho fokotseha ho feteletseng ka lebaka la khaello ea lisebelisoa tsa liphaephe. PVC e na le mocheso o phahameng oa tšebeletso oa 140 ° F; CPVC e na le boholo ba 220 ° F; PP e na le boholo ba 180 ° F; le li-valve tsa PVDF li ka boloka khatello e fihla ho 280 ° F (Setšoantšo sa 2).

Ka lehlakoreng le leng la tekanyo ea mocheso, boholo ba lisebelisoa tsa liphaephe tsa polasetiki li sebetsa hantle haholo mochesong o ka tlaase ho leqhoa. Ha e le hantle, matla a tsitsitseng a eketseha ka liphaephe tsa thermoplastic ha mocheso o fokotseha. Leha ho le joalo, ho hanyetsa ha lipolasetiki tse ngata hoa fokotseha ha mocheso o theoha, 'me bofokoli bo hlaha linthong tse amehang tsa liphaephe. Hafeela li-valve le tsamaiso e kopanetsoeng ea liphaephe li sa khathatsehe, ha li kotsing ka ho otla kapa ho otla ha lintho, 'me liphaephe li sa theohe nakong ea ho sebetsana, liphello tse mpe ho liphaephe tsa polasetiki lia fokotseha.

MEFUTA EA LIHLOOHO TSA THERMOPLASTIC

Li-valve tsa bolo,hlahloba li-valve,li-valve tsa serurubelele li-valve tsa diaphragm li fumaneha ho e 'ngoe le e' ngoe ea lisebelisoa tse fapaneng tsa thermoplastic bakeng sa kemiso ea 80 khatello ea liphaephe tsa liphaephe tse nang le mefuta e mengata ea likhetho le lisebelisoa. Valve e tloaelehileng ea bolo e atisa ho fumanoa e le moralo oa 'nete oa bonngoe ho thusa ho tlosoa ha' mele oa valve bakeng sa tlhokomelo ntle le tšitiso ea ho kopanya liphaephe. Li-valve tsa ho hlahloba thermoplastic li fumaneha e le licheke tsa bolo, licheke tsa swing, y-checks le li-cone checks. Li-valve tsa butterfly li kopana habonolo le li-flange tsa tšepe hobane li lumellana le likoti tsa bolt, li-bolt circles le litekanyo tse akaretsang tsa ANSI Class 150. Bophara bo boreleli ba ka hare ba likarolo tsa thermoplastic bo eketsa feela taolo e nepahetseng ea li-valve tsa diaphragm.

Li-valve tsa bolo ho PVC le CPVC li etsoa ke lik'hamphani tse 'maloa tsa US le tsa kantle ho naha ka boholo ba 1/2 inch ho ea ho 6 inches tse nang le socket, khoele kapa flanged. Moralo oa 'nete oa bonngoe oa li-valve tsa mehleng ea kajeno o kenyelletsa linate tse peli tse thibang 'meleng, tse hatellang litiiso tsa elastomeric lipakeng tsa' mele le lihokelo tsa pheletso. Baetsi ba bang ba bolokile li-valve tsa bolo e tšoanang bolelele le likhoele tsa linate ka lilemo tse mashome ho lumella hore ho be bonolo ho nkela li-valve tsa khale ntle le ho fetola liphaephe tse kopaneng.

Li-valve tse nang le ethylene propylene diene monomer (EPDM) elastomeric seals li lokela ho netefatsoa ho NSF-61G hore li sebelisoe metsing a nooang. Litiiso tsa Fluorocarbon (FKM) elastomeric li ka sebelisoa e le mokhoa o mong bakeng sa litsamaiso tseo ho tsona ho amehang ts'ebelisano ea lik'hemik'hale. FKM le eona e ka sebelisoa lits'ebetsong tse ngata tse kenyelletsang liminerale acid, ntle le hydrogen chloride, litharollo tsa letsoai, li-hydrocarbon tse chlorinated le oli ea petroleum.

Setšoantšo sa 3. Sesepa sa bolo se nang le flanged se khomaretsoeng tanka Setšoantšo sa 4. Sesepa sa ho hlahloba bolo se kentsoeng ka holimo PVC le li-valve tsa bolo ea CPVC, 1/2-inch ka 2 inches, ke khetho e sebetsang bakeng sa lisebelisoa tsa metsi a chesang le a batang moo metsi a mangata a sa sisinyeheng. tšebeletso e ka ba boholo ba 250 psi ho 73 ° F. Li-valve tse kholoanyane tsa bolo, lisenthimithara tse 2-1/2 ho isa ho tse 6, li tla ba le tekanyo e tlase ea khatello ea 150 psi ho 73 ° F. Hangata e sebelisoa phetisong ea lik'hemik'hale, li-valve tsa bolo ea PP le PVDF (Lipalo 3 le 4), tse fumanehang ka boholo ba 1/2-inch ho isa ho 4 inches tse nang le sokete, likhokahano tse khoele kapa tse pheletsong hangata li lekantsoe ho fihlela boholo ba ts'ebeletso ea metsi e sa sisinyeheng. 150 psi ka mocheso o tloaelehileng.

Li-valve tsa ho hlahloba bolo ea thermoplastic li itšetlehile ka bolo e nang le matla a khoheli a itseng ka tlase ho metsi, e le hore haeba khatello e lahleha ka lehlakoreng le ka holimo la noka, bolo e tla teba morao khahlanong le holim'a ho tiisa. Li-valve tsena li ka sebelisoa tšebeletsong e tšoanang le li-valve tsa bolo ea polasetiki tse tšoanang hobane ha li hlahise lisebelisoa tse ncha tsamaisong. Mefuta e meng ea li-valve tsa ho hlahloba e ka kenyelletsa liliba tsa tšepe tse ka 'nang tsa se ke tsa tšoarella libakeng tse senyang.

Setšoantšo sa 5. Belofo ea serurubele e nang le liner elastomericBelofo ea serurubele sa polasetiki ka boholo ba lisenthimithara tse 2 ho isa ho tse 24 e tumme ka liphaephe tse kholoanyane tsa bophara. Baetsi ba li-valve tsa serurubele tsa polasetiki ba nka mekhoa e fapaneng ea ho aha le ho koala libaka. Ba bang ba sebelisa lesela la elastomeric (Setšoantšo sa 5) kapa O-ring, ha ba bang ba sebelisa disc e entsoeng ka elastomeric. Tse ling li etsa 'mele ka thepa e le' ngoe, empa likarolo tse ka hare, tse nang le metsi li sebetsa e le lisebelisoa tsa tsamaiso, ho bolelang hore 'mele oa valve ea serurubele oa polypropylene o ka' na oa e-ba le EPDM liner le PVC disc kapa tse ling tse 'maloa tse nang le li-thermoplastics le li-elastomeric tse atisang ho fumanoa.

Ho kenya valve ea serurubele sa polasetiki ho bonolo hobane li-valve tsena li entsoe hore e be setaele sa li-wafer tse nang le litiiso tsa elastomeric tse etselitsoeng 'mele. Ha ba hloke ho eketsoa ha gasket. E behiloe pakeng tsa li-flange tse peli tsa ho nyalana, ho koala ha valve ea serurubele sa polasetiki ho tlameha ho sebetsoa ka hloko ka ho nyolohela torque ea bolt e khothalletsoang ka mekhahlelo e meraro. Sena se etsoa ho etsa bonnete ba hore ho na le tiiso e lekaneng holim'a metsi le hore ha ho na khatello e sa lekaneng ea mochine e sebelisoang holim'a valve.

Setšoantšo sa 6. Sesepa sa diaphragm Litsebi tsa li-valve tsa tšepe li tla fumana mesebetsi e ka holimo ea li-valve tsa polasetiki tsa diaphragm tse nang le lebili le matšoao a boemo a tloaelehileng (Setšoantšo sa 6); leha ho le joalo, valve ea polasetiki ea diaphragm e ka kenyelletsa melemo e meng e ikhethang ho kenyelletsa le marako a ka hare a boreleli a 'mele oa thermoplastic. Ho tšoana le valve ea bolo ea polasetiki, basebelisi ba li-valve tsena ba na le khetho ea ho kenya moralo oa 'nete oa bonngoe, o ka ba molemo ka ho khetheha bakeng sa mosebetsi oa tlhokomelo holim'a valve. Kapa, ​​​​mosebelisi a ka khetha likhokahano tsa flanged. Ka lebaka la likhetho tsohle tsa 'mele le lisebelisoa tsa diaphragm, valve ena e ka sebelisoa mefuteng e sa tšoaneng ea lik'hemik'hale.

Joalo ka valve efe kapa efe, senotlolo sa ho kenya li-valve tsa polasetiki ke ho khetholla litlhoko tsa ts'ebetso tse kang pneumatic khahlano le motlakase le DC khahlano le matla a AC. Empa ka polasetiki, moqapi le mosebelisi le bona ba tlameha ho utloisisa hore na ke tikoloho ea mofuta ofe e tla pota-pota actuator. Joalokaha ho boletsoe pejana, li-valve tsa polasetiki ke khetho e ntle bakeng sa maemo a senyang, a kenyeletsang libaka tse senyang ka ntle. Ka lebaka lena, lisebelisoa tsa bolulo tsa li-actuator tsa li-valve tsa polasetiki ke tsa bohlokoa ho nahanoa. Baetsi ba li-valve tsa polasetiki ba na le likhetho tsa ho fihlela litlhoko tsa libaka tsena tse senyang ka mokhoa oa li-actuator tse koahetsoeng ka polasetiki kapa mekotla ea tšepe e koahetsoeng ka epoxy.

Joalokaha sehlooho sena se bontša, li-valve tsa polasetiki kajeno li fana ka mefuta eohle ea likhetho bakeng sa likopo tse ncha le maemo.