Ọ na-tumadi ekewet mejupụtara corrugated anwụrụ, net uwe na nkwonkwo. Igwe dị n’ime ya bụ ọkpọka nwere mgbidi dị warara nke nwere stiral dị gburugburu ma ọ bụ akara annular, a na-ejikwa waya igwe na-emepụta paịpụ nke pipụ corrugaed. Ọ joụ na flanges na nsọtụ abụọ nke sooks ar kwekọrọ na akwa akwa na flanges nke ndị ahịa ọkpọkọ.