Ko te wera o te pau tetahi o nga tawhā tino nui; Ko te pamahana whakamahana he tawhā whakahaere nui i roto i te huringa whakamatao; Ko te pāmahana o te casing compressor me te pāmahana wheketere he tohu tino nui me aro nui. He mea nui enei tawhā whakahaere hei whakapai ake i te pai me te mahinga katoa.