Umbhobho weradiyetha ngumbhobho werabha ohambisa isipholileyo sisuka kwimpompo yamanzi ye-injini ukuya kwiradiyetha yayo. Kukho imibhobho emibini yeradiyetha kwi-injini nganye: umbhobho ongenelayo, othatha isisipholisi se-injini eshushu kwi-injini kwaye isise kwiradiyetha, kunye nenye. ngumbhobho wokuphuma, othutha isipholile se-injini ukusuka kwiradiyetha ukuya enjinini. Kunye, imibhobho ijikelezisa isisipholisi phakathi kwe-injini, iradiyetha kunye nempompo yamanzi. Zibalulekile ekugcineni ubushushu obusebenzayo be-injini yesithuthi.