Nyangwemavharuvhu epurasitikidzimwe nguva dzinoonekwa sechigadzirwa chakakosha-sarudzo yekutanga kune vanhu vanogadzira kana kugadzira zvigadzirwa zvepombi zvepurasitiki zvemaindasitiri masisitimu kana vanofanirwa kuve nemidziyo yakachena-ipfupi tichifungidzira kuti mavharuvhu aya haana akawanda anoshandiswa-kuona . Kutaura zvazviri, mavharuvhu epurasitiki emazuva ano ane kushandiswa kwakasiyana-siyana, nokuti marudzi ezvigadzirwa anoramba achiwedzera, uye vagadziri vakanaka vanoda zvinhu izvi zvinoreva kuti kune nzira dzakawanda dzekushandisa zvishandiso izvi zvakawanda.

PASTIC'S PROPERTIES

Zvakanakira zve thermoplastic valves zvakakura-kuora, makemikari uye abrasion resistance; yakatsetseka mukati memadziro; uremu huremu; nyore kuisa; kurarama kwenguva refu; uye mutengo wakaderera wehupenyu. Izvi zvakanakira zvakakonzera kugamuchirwa kwakakura kwemavharuvhu epurasitiki mune zvekutengesa uye maindasitiri mashandisirwo akadai sekugovera mvura, kuchenesa mvura, simbi uye makemikari kugadzirisa, chikafu nemishonga, magetsi emagetsi, mafuta ekunatsa uye moPlastic mavharuvhu anogona kugadzirwa kubva kune akati wandei akasiyana zvinhu zvinoshandiswa. muhuwandu hwekugadzirisa. Mavharuvhu anonyanyozivikanwa ethermoplastic anogadzirwa ne polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene (PP), uye polyvinylidene fluoride (PVDF). PVC neCPVC mavharuvhu anowanzo kubatanidzwa kune pombi masisitimu ne solvent cementing socket ends, kana shinda uye flanged magumo; nepo, PP nePVDF inoda kujoinwa kwepiping system zvikamu, kungave nekupisa-, butt- kana electro-fusion matekinoroji.

Mavharuvhu eThermoplastic anokunda munzvimbo dzinoita ngura, asi anongobatsirawo musevhisi yemvura yakajairika nekuti haana lead-1, anodzivirira dezincification uye haaite ngura. PVC neCPVC pombi masisitimu nemavharuvhu zvinofanirwa kuyedzwa nekupihwa zvitupa kuNSF [National Sanitation Foundation] chiyero 61 chemhedzisiro yehutano, kusanganisira iyo yakaderera lead inodiwa yeAnnex G. Kusarudza zvinhu zvakakodzera zvemvura inoparadza inogona kubatwa nekubvunza mugadziri makemikari kuramba. tungamira uye kunzwisisa mhedzisiro iyo tembiricha ichave nayo pane epurasitiki zvinhu 'simba.

Kunyange zvazvo polypropylene ine hafu yesimba rePVC neCPVC, ine makemikari akawanda anopikisa nokuti hapana zvinonyungudutsa zvinozivikanwa. PP inoita zvakanaka muconcentrated acetic acids uye hydroxides, uye inokodzerawo zvinyoro zvigadziriso zveakawanda acid, alkalis, munyu uye akawanda organic makemikari.

PP inowanikwa seine pigmented kana isina pigmented (yakasikwa) zvinhu. Natural PP yakashatiswa zvakanyanya neultraviolet (UV) mwaranzi, asi makomisheni ane anopfuura 2.5% kabhoni dema pigmentation ane UV yakagadzikana zvakakwana.

PVDF pombi dzemapombi dzinoshandiswa mumhando dzakasiyana dzemaindasitiri ekushandisa kubva kumishonga kusvika kumigodhi nekuda kwesimba rePVDF, tembiricha yekushanda uye kupikisa kemikari kumunyu, maasidhi akasimba, mabhesi edilute uye zvakawanda zvinonyungudutsa organic. Kusiyana nePP, PVDF haina kuderedzwa nechiedza chezuva; zvisinei, purasitiki iri pachena kune chiedza chezuva uye inogona kuburitsa mvura kune UV mwaranzi. Nepo maumbirwo ePVDF echisikigo, asina pigment akanakira kuchena kwepamusoro, kushandiswa kwemukati, kuwedzera pigment yakaita seyechikafu tsvuku inobvumidza kuvhenekwa nezuva pasina mhedzisiro yakaipa pamvura inoyerera.

Masisitimu epurasitiki ane zvipingamupinyi zvekugadzira, sekunzwa kudziya uye kuwedzera kwemafuta uye kuderera, asi mainjiniya anogona uye akagadzira anogara kwenguva refu, anodhura-anoshanda pombi masisitimu enzvimbo dzakajairwa uye dzinoparadza. Iyo huru yekugadzira inotariswa ndeyekuti iyo coefficient yekupisa kwekuwedzera kwepurasitiki yakakura kupfuura simbi-thermoplastic ine kashanu kusvika katanhatu iyo yesimbi, semuenzaniso.

Paunenge uchigadzira masisitimu epombi uye uchifunga nezve maitiro ekuiswa kwevharuvhu uye mavharuvhu anotsigira, yakakosha kutariswa mu thermoplastics ndeyekupisa kwehurefu. Kushungurudzika uye masimba anokonzerwa nekuwedzera kwekupisa uye kuputika kunogona kuderedzwa kana kubviswa nekupa kushanduka mumagadzirirwo epombi kuburikidza nekuchinja nguva dzose munzira kana kuiswa kwezvishwe zvekuwedzera. Nekupa kushanduka uku pamwe chete nepiping system, valve yepurasitiki haizodiwi kutora zvakanyanya kushushikana (Mufananidzo 1).

Nekuti thermoplastics inonzwa tembiricha, kudzvanywa kwevharuvhu kunoderera sezvo tembiricha inokwira. Zvigadzirwa zvepurasitiki zvakasiyana zvine deration inoenderana nekuwedzera tembiricha. Fluid tembiricha inogona kunge isiri iyo yega yekupisa sosi inogona kukanganisa epurasitiki mavharuvhu 'kudzvanywa rating-yepamusoro yekunze tembiricha inoda kuve chikamu chekufunga nezvekugadzira. Mune zvimwe zviitiko, kusagadzira pombi yekunze tembiricha kunogona kukonzera kuderera zvakanyanya nekuda kwekushaikwa kwepombi zvinotsigira. PVC ine tembiricha yepamusoro yebasa ye140°F; CPVC ine huwandu hwe220 ° F; PP ine huwandu hwe180 ° F; uye mavharuvhu ePVDF anogona kuchengetedza kumanikidza kusvika ku280 ° F (Mufananidzo 2).

Kune rumwe rutivi rwechiyero chekushisa, akawanda epurasitiki pombi masisitimu anoshanda zvakanaka mukupisa kuri pasi pechando. Muchokwadi, kusimba kwesimba kunowedzera mu thermoplastic pombi sezvo tembiricha inodzikira. Nekudaro, kuramba kwesimba kwemapurasitiki mazhinji kunodzikira sezvo tembiricha inodonha, uye brittleness inoonekwa mune yakakanganisika pombi zvinhu. Chero bedzi mavharuvhu uye adjoining piping system isina kukanganiswa, isingatyisidzirwe nekurova kana kuputika kwezvinhu, uye pombi isina kudonhedzwa panguva yekubata, mhedzisiro yakaipa kune pombi yepurasitiki inoderedzwa.

MAZHINJI EMAVIVESI ETHERMOPLASTIC

Mavharuvhu ebhora,cheki mavharuvhu,butterfly mavharuvhuuye diaphragm mavharuvhu anowanikwa mune imwe neimwe yezvakasiyana thermoplastic zvinhu zvehurongwa makumi masere ekumanikidza pombi masisitimu ayo anewo akawanda e trim sarudzo uye zvishongedzo. Iyo yakajairwa bhora vharafu inonyanya kuwanikwa seyechokwadi mubatanidzwa dhizaini kuti ifambise kubviswa kwevharuvhu kwekugadzirisa pasina kukanganisa kwekubatanidza pombi. Thermoplastic cheki mavharuvhu anowanikwa sebhora cheki, swing cheki, y-cheki uye cone cheki. Butterfly mavharuvhu anobatana nyore nesimbi flanges nekuti anopindirana nemabhoti maburi, mabhaudhi madenderedzwa uye mativi ese eANSI Kirasi 150. Iyo yakatsetseka mukati medhayamita yezvikamu zve thermoplastic inongowedzera kukutonga chaiko kwemavharuvhu e diaphragm.

Mavharuvhu ebhora muPVC neCPVC anogadzirwa nemakambani akati wandei eUS nevekunze muhukuru 1/2 inch kuburikidza 6 inches ane socket, threaded kana flanged. Iyo yechokwadi mubatanidzwa dhizaini yemazuva ano bhora mavharuvhu anosanganisira nzungu mbiri dzinokaruka pamuviri, kumanikidza elastomeric zvisimbiso pakati pemuviri nemagumo ekubatanidza. Vamwe vagadziri vakachengeta vharafu imwechete yekuisa kureba uye shinda dzenzungu kwemakumi emakore kuti zvibvumire kutsiva nyore kwemavharuvhu ekare pasina kugadziridzwa kune inobatana pombi.

Mavharuvhu ebhora ane ethylene propylene diene monomer (EPDM) elastomeric seals anofanirwa kupihwa chitupa kuNSF-61G kuti ashandiswe mumvura inonwiwa. Fluorocarbon (FKM) elastomeric seals inogona kushandiswa seimwe nzira kune masisitimu uko kugarisana kwemakemikari kuri kunetseka. FKM zvakare inogona kushandiswa mumashandisirwo mazhinji anosanganisira mineral acids, kunze kwehydrogen chloride, munyu mhinduro, chlorinated hydrocarbons uye petroleum oiri.

Mufananidzo 3. A flanged ball valve yakanamirwa kune tankFigure 4. A bhora cheki vharafu yakaiswa verticallyPVC uye CPVC bhora mavharuvhu, 1/2-inch kuburikidza 2 inches, inogoneka sarudzo yemvura inopisa uye inotonhora maapplication apo yakanyanya kusinga vhunduke mvura. sevhisi inogona kunge yakakura se250 psi pa73°F. Mavharuvhu ebhora mahombe, 2-1/2 inches kuburikidza ne6 inches, achange aine pressure yakaderera ye150 psi pa73°F. Inowanzo shandiswa mukutakura makemikari, PP uye PVDF bhora mavharuvhu (Figure 3 ne4), anowanikwa muhukuru 1/2-inch kuburikidza 4 inches ane socket, shinda kana flanged-magumo ekubatanidza anowanzo kuverengerwa kune yakanyanya kusinga vhunduke sevhisi yemvura. 150 psi pane ambient tembiricha.

Thermoplastic bhora cheki mavharuvhu anotsamira pane bhora rine giravhiti rakaderera pane iro remvura, kuitira kuti kana kudzvanywa kukarasika kudivi rekumusoro, bhora rinonyura kumashure richipesana nechisimbiso. Aya mavharuvhu anogona kushandiswa mubasa rimwechete semavharuvhu epurasitiki akafanana nekuti haatauri zvinhu zvitsva kuhurongwa. Mamwe marudzi echeki mavharuvhu angasanganisira zvitubu zvesimbi zvingasagara munzvimbo dzinoparadza.

Mufananidzo 5. Bhavharuvhu yeshavishavi ine elastomeric linerIplastic butterfly valve in saizi 2 inches kusvika 24 inches inofarirwa nemapaipi mahombe dhayamita. Vagadziri vepurasitiki butterfly mavharuvhu vanotora nzira dzakasiyana dzekuvaka nekuisa chisimbiso. Vamwe vanoshandisa elastomeric liner (Mufananidzo 5) kana O-ring, asi vamwe vanoshandisa elastomeric-coated disc. Zvimwe zvinogadzira muviri kubva pane chimwe chinhu, asi mukati, zvakanyoroveswa zvikamu zvinoshanda segadziriro yezvinhu, zvinoreva kuti polypropylene butterfly valve body inogona kunge iine EPDM liner uye PVC disc kana mamwe akati wandei magadzirirwo ane anowanzo kuwanikwa thermoplastics uye elastomeric seals.

Kuiswa kwepurasitiki butterfly valve kwakatwasanuka nekuti mavharuvhu aya anogadzirwa kuti ave wafer style ine elastomeric seals yakagadzirirwa mumuviri. Havadi kuwedzerwa kwegasket. Yakagadzika pakati pemafurange maviri ekukwirana, kubhaurirwa pasi kwevharuvhu yeshavishavi repurasitiki kunofanirwa kubatwa zvine hungwaru nekukwira kusvika kune yakakurudzirwa bhaudhi torque mumatanho matatu. Izvi zvinoitirwa kuve nechokwadi chekusimbisa chisimbiso chepamusoro uye kuti hapana kusaenzana kwema mechanical kusagadzikana kunoshandiswa pavhavha.

Mufananidzo 6. A diaphragm valveMetal valve professionals achawana mabasa epamusoro epurasitiki diaphragm mavharuvhu ane vhiri uye nzvimbo zviratidzo zvinozivikanwa (Mufananidzo 6); zvisinei, iyo yepurasitiki diaphragm valve inogona kusanganisira mamwe mabhenefiti akasiyana anosanganisira akatsetseka mukati memadziro e thermoplastic body. Kufanana nevhavha yebhora repurasitiki, vashandisi vezvivharo izvi vane sarudzo yekuisa dhizaini yekubatana kwechokwadi, iyo inogona kunyanya kubatsira pakugadzirisa basa pavhavha. Kana, mushandisi anogona kusarudza flanged zvinongedzo. Nekuda kwesarudzo dzese dzemuviri uye diaphragm zvinhu, iyi valve inogona kushandiswa mumhando dzakasiyana dzemakemikari.

Kufanana nechero vharafu, kiyi yekubatisa mavharuvhu epurasitiki kutarisa zvinodiwa zvekushandisa senge pneumatic maringe nemagetsi uye DC kurwisa AC simba. Asi nepurasitiki, mugadziri uye mushandisi zvakare anofanirwa kunzwisisa kuti rudzii rwenzvimbo inotenderedza actuator. Sezvambotaurwa, mavharuvhu epurasitiki isarudzo huru yemamiriro ekuora, ayo anosanganisira kunze nharaunda dzinoparadza. Nekuda kweizvi, iyo imba yemagetsi emagetsi mavharuvhu epurasitiki chinhu chakakosha kufunga. Vagadziri vepurasitiki vevharuvhu vane sarudzo dzekusangana nezvinodiwa zveiyi nharaunda dzinoparadza muchimiro chepurasitiki-yakavharwa actuators kana epoxy-yakavharwa simbi makesi.

Sezvinoratidzwa nechinyorwa ichi, mavharuvhu epurasitiki nhasi anopa marudzi ese ezvisarudzo zvekushandisa kutsva uye mamiriro.