Ivalvu yesangoyimveliso yotshintsho lwemizi-mveliso. Nangona ezinye iindlela zoyilo lweevalvu, ezifana neevalvu zeglobe kunye neevalvu zeplagi, zikho ixesha elide, iivalvu zesango bezisoloko ziphethe indawo ephambili kushishino kangangeminyaka emininzi, kwaye kutshanje zinikezele ngesabelo esikhulu semarike kwiindlela zoyilo lweevalvu zebhola kunye neevalvu zebhabhathane.

Umahluko phakathi kwevalvu yesango kunye nevalvu yebhola, ivalvu yeplagi kunye nevalvu yebhabhathane kukuba into yokuvala, ebizwa ngokuba yidiski, isango okanye i-occluder, iphakama ezantsi kwesiqu sevalvu okanye i-spindle, ishiya umzila wamanzi ize ingene phezulu kwevalvu, ebizwa ngokuba yi-bonnet, kwaye ijikeleze nge-spindle okanye i-spindle ngeendlela ezininzi. Ezi valves zivuleka nge-linear motion zikwaziwa ngokuba zii-multi turn okanye ii-linear valves, ngokungafaniyo nee-quarter turn valves, ezine-stem ejikeleza ii-degrees ezingama-90 kwaye aziqhelekanga ukuphakama.

Iivalvu zesango ziyafumaneka ngezinto ezahlukeneyo kunye novavanyo loxinzelelo. Zinobukhulu obahlukeneyo ukusuka kwi-NPS elingana nesandla sakho ukusuka kwi-½ intshi ukuya kwilori enkulu ye-NPS eyi-144 intshi. Iivalvu zesango zenziwe ngee-castings, ii-forgings, okanye izinto ezenziwe nge-welding, nangona uyilo lwe-castings luphambili.

Enye yezona zinto zinqwenelekayo ngeevalvu zesango kukuba zinokuvulwa ngokupheleleyo ngaphandle kokuphazanyiswa okanye ukungqubana okuncinci kwimingxuma yokuhamba kwamanzi. Ukumelana nokuhamba kwamanzi okunikezelwa yivalvu yesango evulekileyo kufana kakhulu nokwecandelo lombhobho elinobukhulu obufanayo bezibuko. Ke ngoko, iivalvu zesango zisaqwalaselwa kakhulu ekuvaleni okanye ekuvuleni/ekuvaleni. Kwezinye iindlela zokuchonga iivalvu, iivalvu zesango zibizwa ngokuba ziivalvu zeglobe.

Iivalvu zesango ngokubanzi azifanelekanga ukulawula ukuhamba okanye ukusebenza kulo naliphi na icala ngaphandle kokuvula ngokupheleleyo okanye ukuvala ngokupheleleyo. Ukusebenzisa ivalvu yesango evuleke kancinci ukujija okanye ukulawula ukuhamba kungonakalisa ipleyiti yevalvu okanye iringi yesihlalo sevalvu, kuba kwindawo yokuhamba evuleke kancinci ebangela ukuxinana, imiphezulu yesihlalo sevalvu iya kungqubana.

Isitayile sevalvu yesango

Ukusuka ngaphandle, uninzi lweevalvu zesango zifana. Nangona kunjalo, kukho iindlela ezahlukeneyo zoyilo. Uninzi lweevalvu zesango luqulathe umzimba kunye nebhonethi, equlethe into yokuvala ebizwa ngokuba yidiski okanye isango. Into yokuvala iqhagamshelwe kwisiqu esidlula kwibhonethi kwaye ekugqibeleni kwivili lesandla okanye kwenye idrayivu yokusebenzisa isiqu. Uxinzelelo olujikeleze isiqu sevalvu lulawulwa kukupakisha okucinezelwe kwindawo yokupakisha okanye kwigumbi.

Ukuhamba kwepleyiti yevalvu yesango kwisiqu sevalvu kugqiba ukuba isiqu sevalvu siyaphakama okanye siyakrufula kwipleyiti yevalvu ngexesha lokuvulwa. Le mpendulo ikwachaza iindlela ezimbini eziphambili zesiqu/idiski zeevalvu zesango: isiqu esinyukayo okanye isiqu esinganyukiyo (i-NRS). Isiqu esinyukayo sesona simbo soyilo lwesiqu/idiski esidumileyo kwimarike yemizi-mveliso, ngelixa isiqu esinganyukiyo sele sithandwa kakhulu yimizi-mveliso yamanzi kunye nemizi-mveliso yepayipi. Ezinye izicelo zeenqanawa ezisasebenzisa iivalvu zesango kwaye zineendawo ezincinci nazo zisebenzisa isitayile se-NRS.

Uyilo oluqhelekileyo lwe-stem/bonnet kwiivalvu zemizi-mveliso yi-external thread and joke (OS&Y). Uyilo lwe-OS&Y lufanelekile ngakumbi kwiindawo ezirhabaxa kuba imisonto ikwindawo engaphandle kwe-fluid seal. Yahlukile kwezinye iindlela zoyilo kuba i-handwheel inamathele kwi-bushing ephezulu ye-joke, kungekhona kwi-stem ngokwayo, ukuze i-handwheel ingaphakami xa i-valve ivuliwe.

Ukwahlulwahlulwa kwemarike yeevalvu zesango

Nangona kwiminyaka engama-50 edlulileyo, iivalvu ezijikelezayo ze-engile yasekunene zithathe inxaxheba enkulu kwimarike yeevalvu zesango, amanye amashishini asaxhomekeke kakhulu kuzo, kuquka ishishini leoyile negesi. Nangona iivalvu zebhola zenze inkqubela phambili kwimibhobho yegesi yendalo, iipayipi zeoyile eluhlaza okanye ezingamanzi zisesezindaweni zeevalvu zesango ezihleli ngaxeshanye.

Kwimeko yobukhulu obukhulu, iivalvu zesango ziseyeyona ndlela iphambili yokusetyenziswa kushishino lokucoca. Ukuqina koyilo kunye neendleko zizonke zobunini (kuquka noqoqosho lokulungisa) zezona zinto zinqwenelekayo kolu yilo lwendabuko.

Ngokuphathelele ukusetyenziswa, iinkqubo ezininzi zokucoca zisebenzisa amaqondo obushushu aphezulu kunobushushu obukhuselekileyo bokusebenza beTeflon, obuyisixhobo esiphambili sesihlalo seevalvu zebhola ezidadayo. Iivalvu zebhabhathane ezisebenza kakuhle kunye neevalvu zebhola ezitywiniweyo zesinyithi ziqala ukusetyenziswa ngakumbi kwizicelo zokucoca, nangona ixabiso lazo lilonke lobunini lidla ngokuba phezulu kuneevalvu zesango.

Ishishini lezityalo zamanzi lisalawulwa ziivalvu zesango lentsimbi. Nokuba zisetyenziswa ngaphantsi komhlaba, zixabiso eliphantsi kwaye zihlala ixesha elide.

Ukusetyenziswa kweshishini lamandlaiivalvu zesango le-alloykwizicelo ezibandakanya uxinzelelo oluphezulu kakhulu kunye namaqondo obushushu aphezulu kakhulu. Nangona ezinye iivalvu zeglobe ezintsha zohlobo lwe-Y kunye neevalvu zebhola ezihleliyo zesinyithi ezenzelwe inkonzo yokuvala zifunyenwe kwisikhululo samandla, iivalvu zesango zisathandwa ngabayili bezityalo kunye nabaqhubi.