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Valavu ya pulagi ya njira zitatu
Valavu ya pulagi ya njira zitatuNdi valavu yozungulira yozungulira yooneka ngati plunger, pozungulira madigiri 90 kuti doko la valavu ndi thupi la valavu likhale la valavu yofanana kapena yosiyana, yotsegula kapena yotseka. Pulavu ya valavu yolumikizira ikhoza kukhala yozungulira kapena yozungulira. Mu mapulagu ozungulira, njira nthawi zambiri zimakhala zamakona anayi; Mu pulagu yocheperako, njirayo imakhala ya trapezoidal. Mawonekedwe awa amapangitsa kapangidwe ka valavu yolumikizira kukhala kopepuka, koma nthawi yomweyo imapanga kutayika kwina. Vavu yolumikizira ndiyoyenera kwambiri kudula ndi kulumikiza njira ndi kusinthasintha, koma kutengera mtundu wa ntchito ndi kukana kukokoloka kwa pamwamba potseka, nthawi zina ingagwiritsidwenso ntchito popopera. Chifukwa kuyenda pakati pa pamwamba potseka kwa valavu yolumikizira kumakhala ndi mphamvu yopukuta, ndipo ikatsegulidwa kwathunthu, imatha kuletsa kwathunthu kukhudzana ndi njira yolumikizira, kotero ingagwiritsidwenso ntchito pazinthu zolumikizira zokhala ndi tinthu toyimitsidwa. Chinthu china chofunikira cha valavu yolumikizira ndichakuti imasintha mosavuta kapangidwe ka njira zambiri, kotero kuti valavu ikhoza kukhala ndi njira ziwiri, zitatu, kapena zinayi zosiyana zolumikizira. Izi zimapangitsa kuti kapangidwe ka mapaipi kakhale kosavuta, zimachepetsa kugwiritsa ntchito ma valavu, komanso zimachepetsa kuchuluka kwa zolumikizira zomwe zimafunikira pazida.
NORTECHis imodzi mwa mayiko otsogola ku China Valavu ya pulagi ya njira zitatu Wopanga & Wopereka.