Ọrụ nke nkwonkwo roba bụ nanị iji mechie ọkara, na nzube ya bụ igbochi ọkara n'ime nkwonkwo roba ka ọ ghara ịpụta. Ihe na-edozi ahụ bụ ihe mmiri mmiri dị na usoro nnyefe nke nkwonkwo roba, ya mere, ọrụ nke nkwonkwo roba na pipeline bụ ịmịnye ujo ma belata mkpọtụ. Akpụkpọ ụkwụ nke nkwonkwo roba dị oke ibu, a na-ejikarị ihe ọkpụkpụ eme ihe n'oge mmepụta. Mgbe ịkpụzi ya, ọ dị mkpa ka a wụsa ya n'ụdị ahụ. N'ọtụtụ ọnọdụ, otu nkwonkwo roba nke otu sphere ga-enwe burrs mgbe a tọhapụrụ ebu ahụ, na mmepụta na ntinye ntinye nke nkwonkwo roba nwere ngwaọrụ akara.