Mphete ya pisitoni ili ndi notch ndipo si mphete yozungulira mu free state. Mbali yake yakunja ndi yayikulu kuposa yamkati mwake ya silinda. Chifukwa chake, ikayikidwa mu silinda limodzi ndi pisitoni, imapanga mphamvu zotanuka ndikumamatira ku khoma la silinda.

Mphete ya pisitoni imakanikizidwa kumunsi kumapeto kwa mpheteyo pansi pa mphamvu ya gasi, kotero kuti mpweya umayenda mozungulira kumbuyo kwa mpheteyo ndikukula, ndipo kuthamanga kwake kumatsika. Panthawi imodzimodziyo, mphamvu ya mpweya wa mpweya pa mphete kumbuyo imapangitsa kuti mphete ya pistoni igwirizane kwambiri ndi khoma la silinda. Pamene mpweya amene kuthamanga wakhala adatchithisira kutayikira ku incision wa mphete woyamba mpweya kumtunda ndege ya mphete yachiwiri mpweya, mpweya mphete mbamuikha pa m'munsi mapeto padziko yachiwiri mphete poyambira. Imayenda mozungulira kumbuyo kwa mphete ndikuwonjezeranso, ndipo kupanikizika kwake kumachepetsedwa kwambiri.

Izi zikapitirira, kuthamanga ndi kuthamanga kwa mpweya wotuluka kuchokera ku mphete yomaliza ya gasi zachepetsedwa kwambiri, choncho kuchuluka kwa mpweya wotuluka kumakhala kochepa kwambiri. Chifukwa chake, chipangizo chosindikizira cha "labyrinth" chopangidwa ndi mphete zingapo za gasi zokhala ndi mabala oyenda pang'onopang'ono chimakwanira kusindikiza bwino mpweya wothamanga kwambiri mu silinda.