Chifukwa chiyani ma valve a mpira amatha kutsegulidwa ndikutsekedwa mwachangu?

Chifukwa chakema valve a mpiraamatha kukwaniritsa mabodza otsegula ndi kutseka mwachangu pamakina awo apadera amakina ndi kapangidwe kake kamadzimadzi. Chigawo chotsegula ndi chotseka ndi gawo lomwe lili ndi dzenje lozungulira, lomwe limatha kuyendetsedwa ndi tsinde la valve kuti lizizungulira madigiri 90 mozungulira mozungulira kuti limalize kusinthana kwa dziko - pamene dzenje la gawolo likugwirizana ndi payipi ya payipi, valavu imatsegulidwa kwathunthu; Pambuyo pozungulira madigiri 90, bowolo limakhala lolunjika ku payipi ndipo valavu imatsekedwa kwathunthu. Mapangidwe a "quarter turn" awa amathandizira kutsegulira ndi kutseka kukhala kozungulira mkati mwa ndege imodzi, kufupikitsa njira yogwirira ntchito.

Kuchokera pamawonekedwe a makina, mpira wavalavu ya mpiraamatengera "kulumikizana kwa mzere" kapena "kulumikizana pamwamba" njira yosindikizira ndi mpando wa valve. Kutenga valavu ya mpira woyandama mwachitsanzo, mpirawo umasunthira kumpando wa valve yotuluka pansi pa kukakamizidwa kwa sing'anga, kupanga chisindikizo chodzingirira ndikuchepetsa kukana kwamphamvu pakutsegula ndi kutseka; Valve yokhazikika ya mpira imathandizidwa ndi mayendedwe a ma valve apamwamba ndi apansi, kotero kuti mpirawo umangofunika kugonjetsa mphamvu yaing'ono yosakanikirana pakati pa mpando wa valve ndi mpira pamene ukuzungulira. Kapangidwe kameneka kamapangitsa kuti malowa akhale osakhudzidwa ndi kukana kwamadzimadzi panthawi yozungulira, makamaka oyenera kupanikizika kwambiri. Mwachitsanzo, mu mafakitale a petrochemical, ma valve a mpira wa pneumatic DN300 amatha kumaliza kutsegula ndi kutseka mu masekondi 0.5, mofulumira kwambiri kuposa ma valve a zipata kapena ma valve a globe omwe amafunikira kuzungulira kangapo.

Mawonekedwe amadzimadzi amadzimadzi amathandiziranso kuyankha mwachangu kwamphamvuvalavu ya mpira. Njira yothamanga ya valavu yodzaza mpira imagwirizana kwathunthu ndi kukula kwapakati kwa payipi, ndipo palibe kutsika kwamphamvu pamene madziwo akudutsa. Sipadzakhala kukana kowonjezera chifukwa cha inertia ya sing'anga panthawi yotsegula ndi kutseka. Mosiyana ndi zimenezi, diski ya valve ya butterfly ikhoza kulepheretsa njira zina zoyendayenda panthawi yozungulira, zomwe zimapangitsa kuti madzi azitha kusuntha pa disc ndikukhudza kutsegula ndi kutseka liwiro; Chipata cha valavu ya chipata chiyenera kukwezedwa molunjika ndi kutsika, ndi kukwapula kwautali ndipo chimakhudzidwa mosavuta ndi kukhuthala kwapakati. Deta yoyesera ikuwonetsa kuti mu mapaipi a DN200, nthawi yotsegulira ndi kutseka kwa mavavu a mpira ndi 40% yaifupi kuposa ya agulugufe amtundu womwewo ndi 70% yaifupi kuposa ya mavavu a pachipata.

Kuonjezera apo, njira yoyendetsera galimoto ya valve ya mpira imaperekanso chithandizo cha kutsegula ndi kutseka kwake mofulumira. Pneumatic, magetsi, kapena hydraulic actuators amatha kutulutsa torque yayikulu nthawi yomweyo, ndikuyendetsa gawolo kuti limalize kuzungulira kwa digirii 90 mkati mwa masekondi 0.1. Mwachitsanzo, mu dongosolo lotsekera mwadzidzidzi gasi, valavu ya mpira wa pneumatic imatha kudula mpweya mkati mwa masekondi 0.3 polandira zizindikiro zamagetsi, kuteteza bwino kuti ngozi zisakule. Kuyankha kwa "millisecond level" uku sikufanana ndi mavavu apamanja achikhalidwe.