ʻO ka lāʻau pahu pahu pālua ʻelua: 1. 360 degere hydraulic rotation no ka hāʻawi ʻana i ka hopena hoʻopaʻa maʻalahi. 2. Hoʻokumuʻia ka valve kaulike i loko o ka cylinder, e holo mālie, mālama i ka ikaika aʻoi aku ka palekana. 3. ʻO ka pahu hoʻomaha hoʻomahaʻelua ala a me ka pahu pale kaulikeʻelua e pale i ka hopena hydraulic ma ke kaʻa.