Ngokwazisa iimfuno zezinto eziluhlaza, iimfuno zoyilo, iimfuno zokuvelisa, iimfuno zokusebenza, iindlela zovavanyo, iimfuno zesicelo senkqubo, kunye nolwalamano phakathi koxinzelelo kunye nobushushu kwimveliso yevalvu yeplastiki yamazwe ngamazwe kunye nemigangatho yendlela yovavanyo, ungayiqonda into yokutywinwa efunekayo kwiivalvu zeplastiki. Iimfuno ezisisiseko zolawulo lomgangatho ezifana novavanyo, uvavanyo lwetorque kunye novavanyo lwamandla okudinwa. Ngendlela yetafile, iimfuno zovavanyo lokutywinwa kwesihlalo, uvavanyo lokutywinwa komzimba wevalvu, uvavanyo lwamandla omzimba wevalvu, uvavanyo lwexesha elide lwevalvu, uvavanyo lwamandla okudinwa kunye netorque yokusebenza efunekayo kwiimfuno zokusebenza kweemveliso zevalvu zeplastiki ziyashwankathelwa. Ngokuxoxa ngeengxaki ezininzi kwimigangatho yamazwe ngamazwe, abavelisi kunye nabasebenzisi beevalvu zeplastiki bavusa inkxalabo.

Njengoko inani leepayipi zeplastiki kumanzi ashushu nabandayo kunye nokusetyenziswa kobunjineli bepayipi kwimizi-mveliso liqhubeka lisanda, ulawulo lomgangatho weevalvu zeplastiki kwiinkqubo zepayipi zeplastiki luya luba lubaluleke ngakumbi nangakumbi.

Ngenxa yeenzuzo zobunzima obulula, ukumelana nokugqwala, ukungafunxwa kwesikali, uqhagamshelo oludibeneyo nemibhobho yeplastiki, kunye nobomi obude benkonzo yeevalvu zeplastiki, iivalvu zeplastiki zisetyenziswa ekunikezelweni kwamanzi (ingakumbi amanzi ashushu kunye nokufudumeza) kunye nezinye iilwelo zemizi-mveliso. Kwinkqubo yemibhobho, iingenelo zokusetyenziswa kwayo azinakuthelekiswa nezinye iivalvu. Okwangoku, ekuvelisweni nasekusetyenzisweni kweevalvu zeplastiki zasekhaya, akukho ndlela ithembekileyo yokuzilawula, nto leyo ebangela umgangatho ongalinganiyo weemveliso zeevalvu zeplastiki zokunikezelwa kwamanzi kunye nezinye iilwelo zemizi-mveliso, nto leyo ebangela ukuvalwa okuthe ngcembe kunye nokuvuza okukhulu kwizicelo zobunjineli. Yakha ingxelo yokuba iivalvu zeplastiki azinakusetyenziswa, nto leyo echaphazela uphuhliso olupheleleyo lwezicelo zeepayipi zeplastiki. Imigangatho yelizwe lam yeevalvu zeplastiki ikwinkqubo yokwenziwa, kwaye imigangatho yemveliso kunye nemigangatho yendlela yazo yenziwe ngokwemigangatho yamazwe ngamazwe.

Kumazwe ngamazwe, iintlobo zeevalvu zeplastiki ziquka ikakhulu iivalvu zebhola, iivalvu zebhabhathane, iivalvu zokujonga, iivalvu zediaphragm, kunye neevalvu zeglobe. Iifom zesakhiwo ziquka iivalvu ezineendlela ezimbini, ezintathu kunye neevalvu ezineendlela ezininzi. Izinto ezisetyenzisiweyo ikakhulu yi-ABS,I-PVC-U, I-PVC-C, I-PB, I-PE,PPkunye nePVDF njl.

Kwimigangatho yamazwe ngamazwe yeemveliso zeevalvu zeplastiki, imfuneko yokuqala zizinto ezisetyenziswa ekuveliseni iivalvu. Umenzi wezinto ezisetyenziswayo kufuneka abe ne-creep failure curve ehlangabezana nemigangatho yeemveliso zepayipi zeplastiki. Kwangaxeshanye, uvavanyo lokutywina, uvavanyo lomzimba wevalvu, kunye novavanyo lokusebenza lwexesha elide, uvavanyo lwamandla okudinwa kunye ne-torque yokusebenza kwevalvu zonke zichaziwe, kwaye ubomi benkonzo yoyilo lwevalvu yeplastiki esetyenziselwa ukuthutha ulwelo kwimizi-mveliso bunikwe iminyaka engama-25.

Iimfuno eziphambili zobugcisa zemigangatho yamazwe ngamazwe

1 Iimfuno zezinto eziluhlaza

Izinto ezisetyenziswa kwivalvu yomzimba, ibhonethi kunye nebhonethi kufuneka zikhethwe ngokuhambelana ne-ISO 15493:2003 “Iinkqubo zemibhobho yeplastiki yemizi-ABS, PVC-U kunye nePVC-C-Iinkcukacha zemibhobho kunye nenkqubo yokufakela-Icandelo 1: Uthotho lweMetric” kunye ne-ISO 15494: 2003 “Iinkqubo zemibhobho yeplastiki yemizi-PB, PE, kunyeI-PP—Ipayipi kunye nokufakelwaIinkcukacha zeNkqubo—Icandelo 1: Uthotho lweMetric.

2 Iimfuno zoyilo

a) Ukuba ivalvu inecala elinye kuphela lokuthwala uxinzelelo, kufuneka iphawulwe ngotolo ngaphandle komzimba wevalvu. Ivalvu enoyilo olulinganayo kufuneka ilungele ukuhamba kolwelo oluhamba ngeendlela ezimbini kunye nokwahlulwa.

b) Inxalenye yokutywina iqhutywa yi-valve stem ukuze ivule kwaye ivale i-valve. Ifanele ibekwe ekupheleni okanye nakweyiphi na indawo embindini yi-friction okanye i-actuators, kwaye uxinzelelo lolwelo alunakutshintsha indawo yalo.

c) Ngokwe-EN736-3, umngxuma omncinci we-valve cavity kufuneka uhlangabezane nala manqaku mabini alandelayo:

— Nakuphi na ukuvuleka apho i-medium ijikeleza khona kwi-valve, akufuneki kube ngaphantsi kwe-90% yexabiso le-DN ye-valve;

— Kwivalvu esakhiwo sayo kufuneka sinciphise ububanzi bendlela edlula kuyo, umenzi uya kunika umngxuma wayo ophantsi.

d) Itywina eliphakathi kwesiqu sevalvu kunye nomzimba wevalvu kufuneka lihambelane ne-EN736-3.

e) Ngokuphathelele ukumelana nokuguguleka kwevalvu, uyilo lwevalvu kufuneka luqwalasele ubomi benkonzo yeendawo ezigugulekileyo, okanye umenzi kufuneka abonise kwimiyalelo yokusebenza isindululo sokutshintsha ivalvu yonke.

f) Izinga lokuhamba elifanelekileyo lazo zonke izixhobo zokusebenza kweevalvu kufuneka lifikelele kwi-3m/s.

g) Xa ibonwa ukusuka phezulu kwevalvu, isiphatho okanye ivili lesandla levalvu kufuneka livale ivalvu ngendlela ejikelezayo.

3 Iimfuno zokuvelisa

a) Iimpawu zezinto ezisetyenzisiweyo ezithengiweyo kufuneka zihambelane nemiyalelo yomenzi kwaye zihlangabezane neemfuno ezisemgangathweni zemveliso.

b) Umzimba wevalvu kufuneka uphawulwe ngekhowudi yezinto eziluhlaza, i-DN yobubanzi, kunye ne-PN yoxinzelelo oluqhelekileyo.

c) Umzimba wevalvu kufuneka uphawulwe ngegama lomenzi okanye uphawu lorhwebo.

d) Umzimba wevalvu kufuneka uphawulwe ngomhla wokuveliswa okanye ikhowudi.

e) Umzimba wevalvu kufuneka uphawulwe ngeekhowudi zeendawo ezahlukeneyo zokuvelisa zomenzi.

4 Iimfuneko zokusebenza kwexesha elifutshane

Ukusebenza kwexesha elifutshane yinto yokuhlolwa kwefektri kumgangatho wemveliso. Isetyenziselwa ikakhulu uvavanyo lokutywina kwesihlalo sevalvu kunye novavanyo lokutywina komzimba wevalvu. Isetyenziselwa ukujonga ukusebenza kokutywina kwevalvu yeplastiki. Kufuneka ukuba ivalvu yeplastiki ingabi nokuvuza kwangaphakathi (ukuvuza kwesihlalo sevalvu). , Akufanele kubekho ukuvuza kwangaphandle (ukuvuza komzimba wevalvu).

Uvavanyo lokutywina kwesihlalo sevalvu kukuqinisekisa ukusebenza kwenkqubo yepayipi yokwahlukanisa ivalvu; uvavanyo lokutywina lomzimba wevalvu kukuqinisekisa ukuvuza kwetywina lesiqu sevalvu kunye nokutywina kwesiphelo ngasinye soqhagamshelo lwevalvu.

Iindlela zokudibanisa ivalvu yeplastiki kwinkqubo yemibhobho zezi:

Uqhagamshelo lwe-butt welding: ububanzi bangaphandle benxalenye yoqhagamshelo lwe-valve bulingana nobubanzi bangaphandle bepayipi, kwaye ubuso besiphelo senxalenye yoqhagamshelo lwe-valve buchasene nobuso besiphelo sepayipi yoqhagamshelo;

Uqhagamshelo lwe-socket bonding: inxalenye yoqhagamshelo lwe-valve ikwimo ye-socket, ebotshelelwe kumbhobho;

Uqhagamshelo lwesokethi ye-electrofusion: inxalenye yoqhagamshelo lwevalvu ikwimo yesokethi enocingo lokufudumeza lombane olubekwe kububanzi bangaphakathi, kwaye luqhagamshelo lwe-electrofusion nombhobho;

Uqhagamshelo lwe-socket hot-melt: inxalenye yoqhagamshelo lwe-valve ikwimo ye-socket, kwaye iqhagamshelwe kumbhobho nge-socket e-hot-melt;

Uqhagamshelo lwe-socket bonding: Inxalenye yoqhagamshelo lwe-valve ikwimo ye-socket, ebotshelelwe kwaye ifakelwe nge-socket nombhobho;

Uqhagamshelo lweringi yokutywina irabha yesokhethi: Inxalenye yoqhagamshelo lwevalvu luhlobo lweringi yokutywina irabha yangaphakathi, efakwe kwisokhethi kwaye iqhagamshelwe nombhobho;

Uqhagamshelo lweFlange: Inxalenye yoqhagamshelo lwevalvu ikwimo yeflange, eqhagamshelwe neflange ekwipayipi;

Uqhagamshelo lwentambo: inxalenye yoqhagamshelo lwevalvu ikwimo yentambo, eqhagamshelwe nentambo ekwipayipi okanye kwindawo yokufakela;

Uqhagamshelo oluphilayo: Inxalenye yoqhagamshelo lwevalvu ikwimo yoqhagamshelo oluphilayo, oluqhagamshelwe kwiipayipi okanye izixhobo.

Ivalvu ingaba neendlela ezahlukeneyo zoqhagamshelo ngaxeshanye.

Ubudlelwane phakathi koxinzelelo lokusebenza kunye nobushushu

Njengoko ubushushu bokusetyenziswa busanda, ubomi benkonzo yeevalvu zeplastiki buya kufutshane. Ukuze kugcinwe ubomi benkonzo efanayo, kuyimfuneko ukunciphisa uxinzelelo lokusetyenziswa.