Valve yothandizira, yomwe imadziwikanso kuti valve pressure relief valve (PRV), ndi mtundu wa valve yotetezera yomwe imagwiritsidwa ntchito kulamulira kapena kuchepetsa kupanikizika mu dongosolo.Ngati kupanikizika sikunayendetsedwe, kungathe kuwonjezereka ndi kuchititsa kusokonezeka kwa ndondomeko, kulephera kwa zida kapena zida, kapena moto.Mwa kupangitsa kuti madzi oponderezedwa atuluke mu dongosolo kudzera mu njira yothandizira, kupanikizika kumachepetsedwa.Kuletsa zotengera zokakamiza ndi zida zina kuti zisavutike ndi zovuta zomwe zimadutsa malire awo opangira, thevalve yothandiziraimamangidwa kapena kukonzedwa kuti itsegulidwe pamtundu wodziwika.

Thevalve yothandiziraimakhala "njira yochepetsera kukana" pamene kupanikizika kwayikidwa kumadutsa chifukwa valavu imatsegulidwa ndipo madzi ena amalowetsedwa mu njira yothandizira.Zosakaniza zamadzimadzi, gasi, kapena zamadzimadzi zomwe zimapatutsidwa m'makina okhala ndi zinthu zoyaka zimatha kubwezedwa kapena kutulutsa mpweya.

[1] mwina amatumizidwa kudzera pa mapaipi omwe amadziwika kuti mutu wamoto kapena mutu wothandizira kupita kumtunda wapakati, wokwera wa gasi komwe amawotchedwa, kutulutsa mpweya woyaka wopanda kanthu mumlengalenga, kapena ndi kutsika kotsika, kachitidwe kamene kamatulutsa mpweya wochuluka.

[2] M'makina omwe si owopsa, madzimadzi nthawi zambiri amatulutsidwa m'mlengalenga kudzera m'mipope yoyenera yomwe imayikidwa bwino kwa anthu ndikumangidwira kuti mvula isalowe, zomwe zingakhudze kuthamanga kwa seti.Kupsyinjika kumasiya kumanga mkati mwa chotengera pamene madzi akuwongolera.Valve idzatseka pamene kupanikizika kukufika pa mphamvu yotsitsimula.Kuchuluka kwa kupanikizika komwe kumayenera kuchepetsedwa musanayambe kubwezeretsa valve kumadziwika kuti blowdown, yomwe nthawi zambiri imawonetsedwa ngati kuchuluka kwa kukakamizidwa kokhazikitsidwa.Mavavu ena amakhala ndi kuphulika kosinthika, ndipo kuphulika kumatha kusinthasintha pakati pa 2% ndi 20%.

Akulangizidwa kuti valavu yotulutsa mpweya mumagetsi othamanga kwambiri ikhale pamlengalenga.Kutsegula kwa valve yothandizira kumapangitsa kuti paipiyi ikhale yowonjezereka muzitsulo zapaipi pansi pa valve yothandizira m'makina omwe chotulukacho chimalumikizidwa ndi mapaipi.Izi nthawi zambiri zimatanthawuza kuti pamene kukakamizidwa komwe kumafunidwa kukwaniritsidwa, valavu yopumulira sidzayambiranso.Ma valve otchedwa "differential" othandizira amagwiritsidwa ntchito kawirikawiri m'makinawa.Izi zikuwonetsa kuti kupanikizika kumangokhalira kudera laling'ono kwambiri kuposa kutsegula kwa valve.

Kuthamanga kwa valve kumapangitsa kuti valavu ikhale yotseguka ngati valavu yatsegulidwa chifukwa kuthamanga kuyenera kutsika kwambiri valve isanatseke.Pamene kuthamanga kwa chitoliro cha chitoliro chotulutsa mpweya kumakwera, ma valve ena othandizira omwe amagwirizanitsidwa ndi chitoliro chotuluka akhoza kutseguka.Ichi ndi chinachake choyenera kukumbukira.Zimenezi zingachititse khalidwe losayenera.