1 Mfundo zazikulu posankha ma valavu

1.1 Fotokozani cholinga cha valavu mu chipangizo kapena chipangizocho

Dziwani momwe valavu imagwirira ntchito: mtundu wa sing'anga yoyenera, kuthamanga kwa ntchito, kutentha kwa ntchito ndi njira zowongolera magwiridwe antchito, ndi zina zotero;

1.2 Kusankha kolondola kwa mtundu wa valavu

Chofunika kwambiri kuti munthu asankhe bwino mtundu wa valavu ndichakuti wopangayo amvetse bwino njira yonse yopangira ndi momwe amagwirira ntchito. Akamasankha mitundu ya valavu, choyamba ayenera kumvetsetsa mawonekedwe a kapangidwe kake ndi momwe valavu iliyonse imagwirira ntchito;

1.3 Dziwani njira yochotsera valavu

Pakati pa maulumikizidwe olumikizidwa ndi ulusi, maulumikizidwe a flange, ndi maulumikizidwe a kumapeto olumikizidwa, awiri oyamba ndi omwe amagwiritsidwa ntchito kwambiri.Ma valve opangidwa ndi ulusiMa valve ambiri ndi okhala ndi mainchesi osakwana 50mm. Ngati mainchesi ndi akulu kwambiri, zidzakhala zovuta kwambiri kuyika ndi kutseka cholumikiziracho. Ma valve olumikizira a Flange ndi osavuta kuyika ndi kusokoneza, koma ndi akuluakulu komanso okwera mtengo kuposa ma valve opangidwa ndi ulusi, kotero ndi oyenera kulumikizana kwa mapaipi a mainchesi ndi kupsinjika kwa mapaipi osiyanasiyana. Maulumikizidwe olumikizidwa ndi oyenera mikhalidwe yolemera kwambiri ndipo ndi odalirika kuposa maulumikizidwe a flange. Komabe, n'kovuta kusokoneza ndikuyikanso ma valve olumikizidwa, kotero kugwiritsidwa ntchito kwawo kumangokhala pazochitika zomwe nthawi zambiri zimatha kugwira ntchito modalirika kwa nthawi yayitali, kapena pomwe mikhalidwe yogwirira ntchito ndi yovuta komanso kutentha kuli kwakukulu;

1.4 Kusankha zipangizo za valavu

Posankha zipangizo zomangira ma valavu, ziwalo zamkati ndi malo otsekera, kuwonjezera pa kuganizira za makhalidwe enieni (kutentha, kupanikizika) ndi makhalidwe a mankhwala (kuwonongeka) kwa chogwirira ntchito, ukhondo wa chogwirira ntchito (kukhalapo kapena kusakhalapo kwa tinthu tolimba) uyeneranso kuganiziridwa. Kuphatikiza apo, muyeneranso kuganizira malamulo oyenera a dzikolo ndi dipatimenti yogwiritsa ntchito. Kusankha koyenera komanso koyenera kwa zipangizo zotsekera kungatsimikizire moyo wotchipa kwambiri wa ntchito komanso magwiridwe antchito abwino kwambiri a valavu. Ndondomeko yosankha zinthu za thupi la valavu ndi: chitsulo chopangidwa ndi chitsulo cha carbon-chitsulo chosapanga dzimbiri, ndipo ndondomeko yosankha zinthu zotsekera mphete ndi: chitsulo cha rabara-mkuwa-alloy-F4;

1.5 Zina

Kuphatikiza apo, kuchuluka kwa madzi omwe akuyenda mu valavu kuyenera kudziwika ndipo valavu yoyenera iyenera kusankhidwa pogwiritsa ntchito chidziwitso chomwe chilipo (monga makatalogu azinthu za valavu, zitsanzo zazinthu za valavu, ndi zina zotero).

2 Chiyambi cha ma valve omwe amagwiritsidwa ntchito kwambiri

Pali mitundu yambiri ya ma valve, kuphatikizapo ma valve a chipata, ma valve a globe, ma valve a throttle, ma valve a gulugufe, ma valve a pulagi, ma valve a mpira, ma valve amagetsi, ma valve a diaphragm, ma valve owunikira, ma valve oteteza, ma valve ochepetsa kupanikizika, misampha ndi ma valve otseka mwadzidzidzi, omwe amagwiritsidwa ntchito kwambiri. Pali ma valve a chipata, ma valve a globe, ma valve a throttle, ma valve a plug, ma valve a gulugufe, ma valve a mpira, ma valve owunikira, ma valve a diaphragm, ndi zina zotero.

2.1Valavu ya chipata

Valavu ya chipata ndi valavu yomwe thupi lake lotsegula ndi kutseka (mbale ya valavu) imayendetsedwa ndi tsinde la valavu ndipo imayenda mmwamba ndi pansi pamwamba pa mpando wa valavu kuti ilumikize kapena kudula njira yamadzimadzi. Poyerekeza ndi mavavu oimitsa, mavavu a chipata ali ndi magwiridwe antchito abwino otsekera, kukana madzi pang'ono, kuyesetsa kochepa kutsegula ndi kutseka, komanso magwiridwe antchito ena. Ndi amodzi mwa mavavu oimitsa omwe amagwiritsidwa ntchito kwambiri. Choyipa chake ndichakuti ndi yayikulu kukula kwake komanso kapangidwe kake kovuta kuposa valavu yoyimitsa. Malo otsekera ndi osavuta kuvala komanso ovuta kusamalira, kotero nthawi zambiri sikoyenera kugwedezeka. Malinga ndi malo a ulusi pa tsinde la valavu ya valavu ya chipata, imagawidwa m'magulu awiri: mtundu wa tsinde lotseguka ndi mtundu wa tsinde lobisika. Malinga ndi mawonekedwe a chipata, chingagawidwe m'mitundu iwiri: mtundu wa wedge ndi mtundu wofanana.

2.2Valavu yoyimitsa

Vavu yozungulira ndi valavu yomwe imatseka pansi. Zigawo zotsegulira ndi zotseka (ma disc a ma valvu) zimayendetsedwa ndi tsinde la valavu kuti zisunthe mmwamba ndi pansi motsatira mzere wa mpando wa valavu (malo otsekera). Poyerekeza ndi ma valavu a chipata, ali ndi magwiridwe antchito abwino, magwiridwe antchito osatseka bwino, kapangidwe kosavuta, kupanga ndi kukonza kosavuta, kukana madzi ambiri, komanso mtengo wotsika. Ndi valavu yoyimitsa yomwe imagwiritsidwa ntchito kwambiri, yomwe imagwiritsidwa ntchito kwambiri m'mapaipi apakati ndi ang'onoang'ono.

2.3 Valavu ya mpira

Gawo lotsegulira ndi kutseka la valavu ya mpira ndi mpira wokhala ndi dzenje lozungulira. Mpirawo umazungulira ndi tsinde la valavu kuti utsegule ndi kutseka valavu. Vavu ya mpirayo ili ndi kapangidwe kosavuta, kutsegula ndi kutseka mwachangu, kugwira ntchito mosavuta, kukula kwake kochepa, kulemera kwake kochepa, zigawo zochepa, kukana madzi pang'ono, kutseka bwino komanso kusamalira kosavuta.