Paipu kila welo: He paipu kila me ka humuhumu ma luna o ka ʻili o ka ʻili kila a i ʻole ka pā kila i piʻo a hoʻololi ʻia i ke ʻano pōʻai a i ʻole ke ʻano huinahā. ʻO ka paia o loko o ka paipu wili he mau iwi ʻaoʻao. ʻO nā huahana nui: ERW steel pipe, LSAW steel pipe a me SSAW steel pipe. ʻO ka paipu kila he ʻano hao lōʻihi loa, i hoʻohana ʻia ma ke ʻano he conduit no ka lawe ʻana i nā wai, e like me ka aila, ke kinoea maoli, ka wai, ke kinoea, ka mahu, etc.