Pipe onigun jẹ orukọ fun paipu onigun mẹrin, iyẹn ni, paipu irin pẹlu ipari ẹgbẹ dogba.O ti ṣe ti yiyi rinhoho, irin lẹhin itọju ilana.Yipada si onigun paipu: gbogbo, awọn rinhoho, irin ti wa ni unpacked, leveled, crimped ati welded lati fẹlẹfẹlẹ kan ti yika paipu, ki o si yiyi sinu kan square paipu lati yika paipu, ati ki o ge sinu awọn ipari ti a beere.