Kunyangwe zvakadaromavharuvhu epurasitikiDzimwe nguva anoonekwa sechigadzirwa chakakosha - sarudzo yekutanga kune vanhu vanogadzira kana kugadzira zvigadzirwa zvepurasitiki zvemaindasitiri kana kuti vanofanira kunge vaine michina yakachena kwazvo - hazvina musoro tichifunga kuti mavharuvhu aya haana mashandisirwo akawanda. Kutaura zvazviri, mavharuvhu epurasitiki emazuva ano ane mashandisirwo akasiyana-siyana, nekuti mhando dzezvinhu dziri kuramba dzichiwedzera, uye vagadziri vakanaka vanoda zvinhu izvi zvinoreva kuti kune nzira dzakawanda dzekushandisa zvishandiso izvi zvinoshanda zvakawanda.

ZVIMBO ZVEPULASTIKI

Zvakanakira mavharuvhu ethermoplastic zvakawanda—kuora, makemikari uye kukwesha; madziro emukati akatsetseka; huremu hushoma; nyore kuisa; tarisiro yekurarama kwenguva refu; uye mutengo wakaderera wehupenyu. Zvakanakira izvi zvakaita kuti mavharuvhu epurasitiki agamuchirwe zvakanyanya mumabasa ekutengeserana nemaindasitiri akadai sekuparadzirwa kwemvura, kurapwa kwemvura yakasviba, kugadziriswa kwesimbi nemakemikari, chikafu nemishonga, mafekitori emagetsi, nzvimbo dzekuchenesa mafuta uye mavharuvhu epurasitiki anogona kugadzirwa kubva pazvinhu zvakasiyana-siyana zvinoshandiswa mumhando dzakasiyana. Mavharuvhu ethermoplastic anonyanya kushandiswa akagadzirwa nepolyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene (PP), uye polyvinylidene fluoride (PVDF). Mavharuvhu ePVC neCPVC anowanzo batanidzwa kumapiping systems ne solvent cementing socket ends, kana threaded and flanged ends; nepo, PP nePVDF zvichida kubatanidzwa kwezvikamu zvepiping system, kungave ne heat-, butt- kana electro-fusion technologies.

Mavharuvhu ethermoplastic anoshanda zvakanaka munzvimbo dzine ngura, asi anobatsirawo pabasa remvura nekuti haana mutobvu, haaparadzi ngura uye haaparadzi ngura. Mapaipi ePVC neCPVC anofanira kuongororwa uye kusimbiswa neNSF [National Sanitation Foundation] standard 61 yemigumisiro yehutano, kusanganisira mutobvu mudiki unodiwa paAnnex G. Kusarudza zvinhu zvakakodzera zvemvura inoparadza kunogona kugadziriswa nekutarisa gwara remugadziri wemakemikari uye kunzwisisa mhedzisiro yekupisa kuchava nayo pasimba rezvinhu zvepurasitiki.

Kunyangwe polypropylene iine hafu yesimba rePVC neCPVC, ine simba rekudzivirira makemikari rinonyanya kushandiswa nekuti hapana zvinonyungudutsa zvinozivikanwa. PP inoshanda zvakanaka muacetic acids nehydroxides dzakasimba, uye yakakodzerawo mishonga isina kunyorova yeacetic acids, alkalis, munyu uye makemikari akawanda eorganic.

PP inowanikwa sechinhu chine ruvara kana chisina ruvara (chemuzvarirwo). PP yechisikigo inoparadzwa zvakanyanya nemwaranzi ye ultraviolet (UV), asi makemikari ane pigmentation yekabhoni nhema inopfuura 2.5% anogadzikiswa zvakakwana neUV.

Masisitimu ePVDF emapaipi anoshandiswa mumaindasitiri akasiyana-siyana kubva kumishonga kusvika kumigodhi nekuda kwesimba rePVDF, tembiricha yekushanda uye kusawirirana nemakemikari nemunyu, maasidhi akasimba, mabhesi akasanganiswa uye organic solvents akawanda. Kusiyana nePP, PVDF haikanganisike nezuva; zvisinei, purasitiki inopenya kuzuva uye inogona kupinza mvura kumwaranzi yeUV. Kunyange zvazvo fomura yePVDF yechisikigo, isina pigment yakanakira kushandiswa mukati memba, kuwedzera pigment yakaita sered-grade food kunobvumira kupenya kuzuva pasina kukanganisa mvura.

Masisitimu epurasitiki ane matambudziko ekugadzira, akadai sekusagona kupisa, kuwedzera kwekupisa uye kudzikira, asi mainjiniya vanogona uye vakagadzira masisitimu emapaipi anogara kwenguva refu uye asingadhuri enzvimbo dzakajairika uye dzinopisa. Chinhu chikuru chinofungidzirwa pakugadzira ndechekuti chiyero chekuwedzera kupisa kwemapurasitiki chakakura kupfuura simbi—thermoplastic yakapetwa kashanu kusvika katanhatu pane yesimbi, semuenzaniso.

Pakugadzira masisitimu emapaipi uye kufunga nezvemhedzisiro yekuiswa kwemavharuvhu uye zvinotsigira mavharuvhu, chinhu chakakosha mu thermoplastics kurebeswa kwekupisa. Kushushikana uye masimba anokonzerwa nekuwedzera kwekupisa uye kudzikira kunogona kuderedzwa kana kubviswa nekupa kuchinjika mumasisitimu emapaipi kuburikidza nekuchinja kwakawanda munzira kana kuiswa kwezvirukwa zvekuwedzera. Nekupa kuchinjika uku pamwe chete nesisitimu yemapaipi, vharuvhu yepurasitiki haizodiwi kuti itore kushushikana kwakawanda (Mufananidzo 1).

Nekuti thermoplastics inonzwa tembiricha, chiyero chekumanikidzwa kwevharuvhu chinoderera kana tembiricha ichikwira. Zvinhu zvakasiyana zvepurasitiki zvine kukanganiswa kunoenderana nekupisa kwakawedzera. Tembiricha yemvura inogona kunge isiriyo yega sosi yekupisa inogona kukanganisa chiyero chekumanikidzwa kwemavharuvhu epurasitiki—tembiricha yepamusoro yekunze inofanira kunge iri chikamu chekufunga nezvekugadzira. Mune zvimwe zviitiko, kusagadzira tembiricha yekunze yepombi kunogona kukonzera kudzikira kwakanyanya nekuda kwekushaikwa kwezvitsigiro zvepombi. PVC ine tembiricha yepamusoro yekushandira ye140°F; CPVC ine chiyero chepamusoro che220°F; PP ine chiyero chepamusoro che180°F; uye mavharuvhu ePVDF anogona kuchengetedza kumanikidzwa kusvika 280°F (Mufananidzo 2).

Kune rimwe divi rechiyero chekupisa, masisitimu mazhinji epurasitiki anoshanda zvakanaka kana tembiricha dziri pasi pechando. Kutaura zvazviri, simba rekusunga rinowedzera mupombi dzethermoplastic sezvo tembiricha ichidzikira. Zvisinei, kuramba kusimba kwemapurasitiki mazhinji kunodzikira kana tembiricha ichidzikira, uye kuputsika kunoonekwa muzvinhu zvepombi zvakakanganiswa. Chero bedzi mavharuvhu nemasisitimu epombi ari pedyo asina kukanganiswa, asina kukuvadzwa nekuputika kana kuputika kwezvinhu, uye pombi isina kudonhedzwa panguva yekubata, migumisiro yakaipa kumapombi epurasitiki inoderedzwa.

Mhando dzemavharuvhu eThermoplastic

Mavharuvhu ebhora,mavharuvhu ekuongorora,mavharuvhu eshavishaviuye mavharuvhu ediaphragm anowanikwa mune imwe neimwe yezvinhu zvakasiyana zvethermoplastic zvehurongwa hwemapombi ekuderedza kumanikidzwa kweschedule 80 anewo akawanda magadzirirwo e trim nezvimwe zvinoshandiswa. Vharuvhu yebhora yakajairika inowanzoonekwa sedhizaini chaiyo yekubatanidza kubvisa muviri wevharuvhu kuti igadziriswe pasina kukanganisa mapombi ekubatanidza. Mavharuvhu ekutarisa ethermoplastic anowanikwa sekutarisa bhora, kutarisa kwe swing, kutarisa y uye kutarisa kwekoni. Mavharuvhu eshavishavi anosangana zviri nyore nesimbi nekuti anoenderana nemaburi emabhoruvhu, madenderedzwa emabhoruvhu uye saizi yese yeANSI Class 150. Dhayamita yemukati yakatsetseka yezvikamu zvethermoplastic inongowedzera kutonga kwakarurama kwemavharuvhu ediaphragm.

Mavharuvhu ebhora muPVC neCPVC anogadzirwa nemakambani akati wandei ekuAmerica neekunze ane saizi 1/2 inch kusvika 6 inches ane socket, threaded kana flanged connections. Dhizaini chaiyo yemavharuvhu ebhora emazuva ano inosanganisira nzungu mbiri dzinosungirirwa pamuviri, dzichidzvanya elastomeric seals pakati pemuviri nemagumo econnectors. Vamwe vagadziri vakachengetedza kureba kwekuisa vharuvhu yebhora uye threads dzenzungu kwemakumi emakore kuti zvive nyore kutsiva mavharuvhu ekare pasina kugadziriswa kune pombi iri pedyo.

Mavharuvhu ebhora ane ethylene propylene diene monomer (EPDM) elastomeric seals anofanira kunge akanyoreswa kuNSF-61G kuti ashandiswe mumvura inonwiwa. Fluorocarbon (FKM) elastomeric seals inogona kushandiswa senzira yekushandiswa mumasystems ane chekuita nekuenderana kwemakemikari. FKM inogonawo kushandiswa mumashandisirwo akawanda ane mineral acids, kunze kwehydrogen chloride, salt solutions, chlorinated hydrocarbons nemafuta epetroleum.

Mufananidzo 3. Vharuvhu yebhora yakasungirirwa patangi Mufananidzo 4. Vharuvhu yekutarisa bhora yakaiswa yakatwasuka. Mavharuvhu ePVC neCPVC, ane 1/2-inch kusvika 2 inches, isarudzo inoshanda yekushandiswa kwemvura inopisa neinotonhora uko mvura isingatsvedzeri inogona kusvika 250 psi pa73°F. Mavharuvhu ebhora akakura, ane 2-1/2 inches kusvika 6 inches, ane pressure rating yakaderera ye150 psi pa73°F. Anowanzoshandiswa mukufambisa makemikari, mavharuvhu ebhora ePP nePVDF (Mufananidzo 3 ne4), anowanikwa muhukuru hwe1/2-inch kusvika 4 inches ane socket, threaded kana flanged-end connections anowanzo verengerwa kune mvura isingatsvedzeri yepamusoro ye150 psi pakupisa kwemhepo.

Mavharuvhu ekuongorora bhora ethermoplastic anovimba nebhora rine simba guruva risingasviki remvura, zvekuti kana kumanikidzwa kukadonha kumusoro, bhora rinonyura richidzokera pamusoro pechisimbiso. Mavharuvhu aya anogona kushandiswa sebasa rakafanana nemavharuvhu epurasitiki akafanana nekuti haapi zvinhu zvitsva musystem. Mamwe marudzi emavharuvhu ekuongorora anogona kusanganisira masipiringi esimbi angasagara kwenguva refu munzvimbo dzine ngura.

Mufananidzo 5. Vharuvhu remapuruguru rine elastomeric liner. Vharuvhu remapuruguru repurasitiki rine saizi 2 inches kusvika 24 inches rakakurumbira kune masisitimu emapaipi akakura. Vagadziri vemapuruguru epurasitiki vanoshandisa nzira dzakasiyana dzekuvaka nekuvhara nzvimbo. Vamwe vanoshandisa elastomeric liner (Mufananidzo 5) kana O-ring, nepo vamwe vachishandisa elastomeric-coated disc. Vamwe vanogadzira muviri kubva pane chimwe chinhu, asi zvikamu zvemukati, zvakanyorova zvinoshanda sezvinhu zvesystem, zvichireva kuti muviri wevharuvhu remapuruguru repolypropylene unogona kunge uine EPDM liner nePVC disc kana zvimwe zvinhu zvakasiyana-siyana zvine thermoplastics uye elastomeric seals.

Kuisa vharuvhu repurasitiki remapuruguru kuri nyore nekuti mavharuvhu aya akagadzirwa nenzira yewafer ane elastomeric seals akagadzirwa mumuviri. Haadi kuwedzerwa gasket. Pakati pemaflange maviri ekubatanidza, kudzika kwevharuvhu repurasitiki remapuruguru kunofanira kubatwa nokungwarira nekuwedzera kusvika pabhoruvhu rinokurudzirwa muzvikamu zvitatu. Izvi zvinoitwa kuti ive nechokwadi chekuti chisimbiso chakaenzana pamusoro uye kuti hapana kumanikidzwa kwemechanical kuri kuiswa pavharuvhu.

Mufananidzo 6. Vharuvhu yediaphragm Nyanzvi dzevharuvhu dzesimbi dzichawana mabasa epamusoro emavharuvhu epurasitiki ane zviratidzo zvevhiri nenzvimbo zvinozivikanwa (Mufananidzo 6); zvisinei, vharuvhu yepurasitiki inogona kusanganisira zvimwe zvakanakira zvinosanganisira madziro emukati akatsetseka emuviri wethermoplastic. Kufanana nevharuvhu yebhora yepurasitiki, vashandisi vevharuvhu idzi vane sarudzo yekuisa dhizaini chaiyo yeyuniyoni, iyo inogona kubatsira zvakanyanya pabasa rekugadzirisa vharuvhu. Kana, mushandisi anogona kusarudza kubatana kwakapfava. Nekuda kwesarudzo dzese dzemuviri nezvinhu zvediaphragm, vharuvhu iyi inogona kushandiswa mumhando dzakasiyana dzemakemikari.

Kufanana nechero vharuvhu, chinhu chikuru chekushandisa mavharuvhu epurasitiki ndechekuona zvinodiwa pakushanda zvakaita semagetsi epneumatic kana emagetsi uye DC kana AC. Asi nepurasitiki, mugadziri nemushandisi vanofanirwawo kunzwisisa kuti rudzii rwenzvimbo ichatenderedza actuator. Sezvambotaurwa, mavharuvhu epurasitiki isarudzo yakanaka yemamiriro ezvinhu anoparadza, anosanganisira nharaunda dzinoparadza kunze. Nekuda kweizvi, zvinhu zvekugara zveactuator zvemavharuvhu epurasitiki zvakakosha kufunga nezvazvo. Vagadziri vemavharuvhu epurasitiki vane sarudzo dzekusangana nezvinodiwa nenzvimbo idzi dzinoparadza muchimiro cheactuator dzakafukidzwa nepurasitiki kana epoxy-coated metal cases.

Sezvinoratidzwa nechinyorwa chino, mavharuvhu epurasitiki nhasi anopa mhando dzakasiyana dzesarudzo dzezvishandiso zvitsva nemamiriro ezvinhu.