Nubwovalve za pulasitikirimwe na rimwe bifatwa nk'ikintu cyihariye - amahitamo ya mbere ku bantu bakora cyangwa bashushanya imiyoboro ya pulasitiki yo gukoresha mu nganda cyangwa bagomba kugira ibikoresho bisukuye cyane - ni mu magambo make iyo tuvuze ko izi valve zidafite uburyo bwinshi bwo gukoresha. Mu by'ukuri, valve za pulasitiki zo muri iki gihe zifite uburyo bwinshi bwo gukoresha, kuko ubwoko bw'ibikoresho bukomeje kwaguka, kandi abashushanya beza bakeneye ibyo bikoresho bivuze ko hari uburyo bwinshi bwo gukoresha ibi bikoresho bifite imikorere myinshi.

IMITUNGO YA PLASTIKI

Ibyiza by'udupira twa thermoplastic ni byinshi—kwangirika, kudakomera mu by'imiti no kwangirika; inkuta z'imbere zoroshye; uburemere bworoheje; koroshya gushyiraho; kumara igihe kirekire; ndetse n'igiciro gito cy'ubuzima. Izi nyungu zatumye udupira twa pulasitiki twemerwa cyane mu bikorwa by'ubucuruzi n'inganda nko gukwirakwiza amazi, gutunganya amazi yanduye, gutunganya ibyuma n'imiti, ibiribwa n'imiti, inganda z'amashanyarazi, inganda zitunganya peteroli na moudupira twa pulasitiki dushobora gukorwa mu bikoresho bitandukanye bikoreshwa mu buryo butandukanye. Udupira twa thermoplastic dukunze gukoreshwa cyane ni utwa polivinili kloride (PVC), polivinili kloride (CPVC), polivinili (PP), na polivinilidene fluoride (PVDF). Udupira twa PVC na CPVC dukunze guhuzwa n'imiyoboro hakoreshejwe impera z'imiyoboro zikora sima, cyangwa impera z'imigozi n'izifunganye; mu gihe PP na PVDF bisaba guhuza ibice by'imiyoboro, haba hakoreshejwe ikoranabuhanga rikoresha ubushyuhe, ubushyuhe cyangwa amashanyarazi.

Valve za thermoplastic zirakomeye cyane mu bidukikije byangiza, ariko nazo ni ingirakamaro mu gutanga amazi muri rusange kuko nta diyabete zikoreshwa, ntizishobora kwangiza kandi ntizishobora kwangiza. Sisitemu n'udupira twa PVC na CPVC bigomba gupimwa no kwemezwa hakurikijwe ibipimo ngenderwaho bya NSF [National Sanitation Foundation] 61 ku ngaruka ku buzima, harimo n'ibipimo bike by'urutare ku mugereka G. Guhitamo ibikoresho bikwiye byo gukoresha amazi yangiza bishobora gukorwa ukurikije ubuyobozi bw'uruganda rurwanya imiti no gusobanukirwa ingaruka ubushyuhe buzagira ku mbaraga z'ibikoresho bya pulasitiki.

Nubwo polypropylene ifite kimwe cya kabiri cy'imbaraga za PVC na CPVC, ifite ubushobozi bwo kurwanya imiti myinshi kuko nta bintu bizwi biyungurura. PP ikora neza muri aside asetiki na hydroxides, kandi ikwiriye no mu bisubizo byoroheje bya aside nyinshi, alkali, umunyu n'ibindi binyabutabire byinshi by'umwimerere.

PP iboneka nk'ibikoresho bifite irangi cyangwa bidafite ibara (bisanzwe). PP karemano yangirika cyane n'imirasire ya ultraviolet (UV), ariko ibintu birimo ibara ry'umukara rya karubone rirenga 2.5% birahamye neza mu mirasire ya UV.

Imiyoboro ya PVDF ikoreshwa mu nganda zitandukanye kuva ku bucuruzi bw'imiti kugeza ku bucukuzi bw'amabuye y'agaciro kubera imbaraga za PVDF, ubushyuhe bw'akazi n'ubudahangarwa bwa shimi ku myunyu, aside ikomeye, ibinyabutabire byinshi biva mu bimera n'ibindi bintu bisukura. Bitandukanye na PP, PVDF ntabwo yangizwa n'izuba; icyakora, pulasitiki irabagirana ku zuba kandi ishobora gushyira amazi ku mirasire ya UV. Nubwo PVDF isanzwe, idafite ibara ry'uruhu ari nziza cyane mu gushyira mu bikorwa mu nzu, kongeramo ibara nk'umutuku wo mu rwego rw'ibiribwa byatuma umuntu ahura n'izuba nta ngaruka mbi ku buryo amazi akoreshwa.

Sisitemu za pulasitiki zifite imbogamizi mu miterere yazo, nko kuba zishobora guhangana n’ubushyuhe n’ubwiyongere bw’ubushyuhe n’igabanuka ry’ubushyuhe, ariko injeniyeri zishobora kandi zarateguye sisitemu z’imiyoboro iramba kandi ihendutse ku bidukikije rusange kandi byangiza. Igitekerezo cy’ingenzi mu miterere yazo ni uko igipimo cy’ubwiyongere bw’ubushyuhe bwa pulasitiki kiruta icyuma—urugero, thermoplastic ikubye inshuro eshanu kugeza esheshatu ugereranyije n’icyuma.

Mu gihe cyo gushushanya sisitemu z'imiyoboro no gusuzuma ingaruka ku ishyirwa ry'imvange n'ibishyigikirwa bya vali, ikintu cy'ingenzi mu by'ubushyuhe ni ukwiyongera k'ubushyuhe. Imihangayiko n'imbaraga bituruka ku kwaguka no guhindagurika k'ubushyuhe bishobora kugabanuka cyangwa bigakurwaho binyuze mu gutanga ubworoherane mu sisitemu z'imiyoboro binyuze mu guhindura kenshi icyerekezo cyangwa gushyiramo imiyoboro yo kwaguka. Mu gutanga ubwo bworoherane ku buryo bwo kwaguka, vali ya pulasitiki ntizasabwa kwakira uburemere bungana n'ubwo (Ishusho ya 1).

Kubera ko thermoplastics zishobora kwitabwaho n'ubushyuhe, igipimo cy'umuvuduko wa valve kigabanuka uko ubushyuhe bwiyongera. Ibikoresho bitandukanye bya pulasitiki bifite ihindagurika rijyanye n'ubushyuhe bwiyongera. Ubushyuhe bw'amazi bushobora kuba atari bwo bwonyine bushobora kugira ingaruka ku gipimo cy'umuvuduko wa valve za pulasitiki—ubushyuhe bwo hanze bugomba kuba igice cy'isuzuma ry'imiterere. Hari ubwo kudashushanya ubushyuhe bwo hanze bw'imiyoboro bishobora gutuma habaho gucika intege cyane bitewe no kutagira imiyoboro ishyigikira. PVC ifite ubushyuhe ntarengwa bwa 140°F; CPVC ifite ubushyuhe ntarengwa bwa 220°F; PP ifite ubushyuhe ntarengwa bwa 180°F; kandi valve za PVDF zishobora kugumana umuvuduko kugeza kuri 280°F (Ishusho ya 2).

Ku rundi ruhande rw'ubushyuhe, uburyo bwinshi bwo gufunga imiyoboro ya pulasitiki bukora neza cyane mu bushyuhe buri munsi y'ubukonje. Mu by'ukuri, imbaraga zo gufunga ziyongera mu miyoboro ya thermoplastic uko ubushyuhe bugabanuka. Ariko, ubushobozi bwo kudakora neza kwa pulasitiki nyinshi buragabanuka uko ubushyuhe bugabanuka, kandi ibintu byangiritse bikagaragara mu miyoboro yangiritse. Igihe cyose imiyoboro n'imiyoboro ihegereye bitahungabanyijwe, bitabangamiwe no gukubitwa cyangwa gukubitwa n'ibintu, kandi imiyoboro idatakaye mu gihe cyo kuyikoresha, ingaruka mbi ku miyoboro ya pulasitiki ziragabanuka.

UBWOKO BWA VALVES Z'ISHUSHO

Vali z'umupira,valve zo kugenzura,valve z'ibinyugunyugukandi uturindantoki dukoreshwa mu gupima ikirere (diaphragm valves) turaboneka muri buri kimwe mu bikoresho bitandukanye bya thermoplastic kuri sisitemu ya 80 yo gupima umuvuduko, ifite kandi amahitamo menshi yo kugabanya n'ibindi bikoresho. Valve isanzwe y'umupira ikunze kugaragara nk'igishushanyo mbonera cy'uburyo bworoshye bwo koroshya gukuraho umubiri wa valve kugira ngo ikomeze gukoreshwa nta kibazo cy'imiyoboro ihuza. Valve zo kugenzura thermoplastic ziboneka mu buryo bwo kugenzura umupira, kugenzura swing, kugenzura y no kugenzura cone. Valve z'ibinyugunyugu zoroshye guhura n'uturindantoki tw'icyuma kuko zihuye n'imyobo y'uturindantoki, uruziga rw'uturindantoki n'ingano rusange ya ANSI Class 150. Ubugari bw'imbere bw'ibice bya thermoplastic bworoshye bwongera gusa ku kugenzura neza kwa valve za diaphragm.

Udupira tw’umupira muri PVC na CPVC dukorwa n’ibigo byinshi byo muri Amerika n’amahanga mu bunini buri hagati ya santimetero 1/2 na santimetero 6, dufite aho duhurira, dufite imigozi cyangwa udupira dufatanye. Imiterere nyayo y’udupira tw’umupira dugezweho irimo utubuto tubiri dufata ku mubiri, tugakanda imigozi ya elastomeric hagati y’umubiri n’udupira two ku mpera. Bamwe mu bakora uruganda bagiye bagumana uburebure bumwe bw’udupira tw’umupira n’imigozi ya utubuto mu myaka ibarirwa muri za mirongo kugira ngo byoroshye gusimbuza utubuto twa kera tudahinduye imiyoboro iri iruhande.

Udupira tw’umupira dufite ethylene propylene diene monomer (EPDM) elastomeric seals tugomba kwemezwa na NSF-61G kugira ngo dukoreshwe mu mazi meza. Udupira tw’umukara wa Fluorocarbon (FKM) elastomeric seals dushobora gukoreshwa nk'ubundi buryo bwo gukoresha imiti aho ikibazo kijyanye n’ibinyabutabire. FKM ishobora kandi gukoreshwa mu bikorwa byinshi birimo aside minerale, usibye hydrogen chloride, umunyu, hydrocarbons chlorine na peteroli.

Ishusho ya 3. Valve y'umupira ifite flange ifatanye n'ikigegaIshusho ya 4. Valve yo gusuzuma umupira ishyizwe mu buryo burambuye. Valve za PVC na CPVC, kuva kuri santimetero 1.5 kugeza kuri santimetero 2.5, ni amahitamo meza yo gukoresha amazi ashyushye n'akonje aho serivisi ntarengwa yo gukoresha amazi idahindagurika ishobora kuba nziza nka psi 2.5 kuri dogere 73. Valve nini z'umupira, kuva kuri santimetero 2.5 kugeza kuri santimetero 6, zizaba zifite igipimo cyo hasi cy'umuvuduko wa psi 1.5 kuri dogere 73. Ikoreshwa cyane mu gutwara imiti, Valve za PP na PVDF (Ishusho ya 3 na 4), ziboneka mu ngano kuva kuri santimetero 1.5 kugeza kuri santimetero 2.5 hamwe n'imiyoboro ifite aho ihurira, ifite imigozi cyangwa flange ikunze kugaragazwa ku gipimo ntarengwa cy'amazi adahindagurika kugeza kuri dogere 1.5 ku bushyuhe bw'ikirere.

Amavali yo kugenzura umupira wa thermoplastic yishingikiriza ku mupira ufite uburemere bwihariye buri munsi y’amazi, ku buryo iyo umuvuduko utakaye ku ruhande rwo hejuru, umupira uzasubira inyuma ku gice cyo hejuru cy’umuyoboro. Izi vali zishobora gukoreshwa mu buryo bumwe n’amavali yo kugenzura umupira wa pulasitiki kuko adashyiramo ibikoresho bishya muri sisitemu. Ubundi bwoko bwa vali yo kugenzura bushobora kuba burimo amasoko y’icyuma ashobora kudamara igihe kirekire ahantu hangiritse.

Ishusho ya 5. Valve y'ikinyugunyugu ifite umugozi wa elastomeric Valve y'ikinyugunyugu ya pulasitiki ifite ingano ya santimetero 2 kugeza kuri santimetero 24 ikunzwe cyane mu miyoboro minini y'umurambararo. Abakora valves za pulasitiki z'ikinyugunyugu bafata uburyo butandukanye mu bwubatsi no gufunga ubuso. Bamwe bakoresha umugozi wa elastomeric (Ishusho ya 5) cyangwa impeta ya O, mu gihe abandi bakoresha disiki ifite elastomeric. Bamwe bakora umubiri mu bikoresho bimwe, ariko ibice by'imbere, bitose bikoreshwa nk'ibikoresho by'imikorere, bivuze ko umubiri wa valve y'ikinyugunyugu ya polypropylene ushobora kuba urimo umugozi wa EPDM na disiki ya PVC cyangwa ibindi bintu byinshi bifite thermoplastics zisanzwe ziboneka hamwe n'udupfundikizo twa elastomeric.

Gushyiraho valve ya pulasitiki y'ibinyugunyugu biroroshye kuko izi valve zakozwe mu buryo bwa wafer hamwe n'udupfundikizo twa elastomeric twagenewe umubiri. Ntibisaba kongerwamo gasket. Hagati y'udupfundikizo tubiri two guhuza, gufunga valve ya pulasitiki y'ibinyugunyugu bigomba gukorwa neza ukoresheje imbaraga za bolt zisabwa mu byiciro bitatu. Ibi bikorwa kugira ngo habeho gufunga neza hejuru y'ubuso kandi nta stress ingana ikoreshwa kuri valve.

Ishusho ya 6. Valve ya diaphragm Abahanga mu byuma bazasanga imikorere myiza ya valve za diaphragm za pulasitiki zifite ibimenyetso by'uruziga n'aho ziherereye imenyerewe (Ishusho ya 6); icyakora, valve ya diaphragm ya pulasitiki ishobora kuba irimo ibyiza bimwe na bimwe birimo inkuta z'imbere z'umubiri wa thermoplastic. Kimwe na valve ya pulasitiki, abakoresha izi valve bafite amahitamo yo gushyiraho igishushanyo mbonera cy'ubumwe, gishobora kuba ingirakamaro cyane mu mirimo yo kubungabunga valve. Cyangwa, umukoresha ashobora guhitamo imiyoboro ifatanye. Kubera amahitamo yose y'umubiri n'ibikoresho bya diaphragm, iyi valve ishobora gukoreshwa mu buryo butandukanye bwa shimi.

Kimwe n'imvange iyo ari yo yose, ikintu cy'ingenzi mu gushyiraho imvange za pulasitiki ni ukumenya ibisabwa mu mikorere nko gukoresha ingufu z'amashanyarazi n'amashanyarazi ndetse na DC ugereranije na AC. Ariko hamwe na pulasitiki, umuhanga mu byayikoze n'umukoresha agomba no gusobanukirwa ubwoko bw'ibidukikije bizakikije imvange. Nkuko byavuzwe mbere, imvange za pulasitiki ni amahitamo meza mu bihe byangiza, harimo n'ibidukikije byangiza inyuma. Kubera iyo mpamvu, ibikoresho byo mu nzu by'imvange za pulasitiki ni ingenzi cyane. Abakora imvange za pulasitiki bafite amahitamo yo guhaza ibyo bidukikije byangiza mu buryo bwa pulasitiki cyangwa imvange z'icyuma zashyizwemo epoxy.

Nk’uko iyi nkuru ibigaragaza, uturindantoki twa pulasitiki muri iki gihe dutanga amahitamo menshi ku mikoreshereze mishya n’ibihe bishya.