API 5Lʻo ia ke kūlana no ka paipu laina kila i hoʻohana ʻia no ka lawe ʻana i ka ʻaila, ke kinoea kūlohelohe, a me ka wai. Uhi ke kūlana i kekahi mau ʻano kila like ʻole, ʻo X42 a me X52 ʻelua mau ʻano maʻamau. ʻO ka ʻokoʻa nui ma waena o X42 a me X52 ko lākou mau waiwai mechanical, ʻoiai ka ikaika yield a me ka ikaika tensile.

X42ʻO ka ikaika haʻahaʻa loa o ka paipu kila X42 he 42,000 psi (290 MPa), a ʻo kona ikaika tensile mai 60,000-75,000 psi (415-520 MPa). Hoʻohana nui ʻia ka paipu kila X42 i nā ʻōnaehana paipu me nā koi kaomi waena a me ka ikaika, kūpono no ka lawe ʻana i nā mea e like me ka ʻaila, ke kinoea kūlohelohe, a me ka wai.

X52ʻO ka ikaika haʻahaʻa loa o ka paipu kila X52 he 52,000 psi (360 MPa), a ʻo ka ikaika tensile mai 66,000-95,000 psi (455-655 MPa). Ke hoʻohālikelike ʻia me X42, ʻoi aku ka ikaika o ka paipu kila X52 a kūpono no nā ʻōnaehana paipu me nā koi kaomi a me ka ikaika kiʻekiʻe.

Ma ke ʻano o ke kūlana hoʻouna,Kūlana API 5Lkuhikuhi i nā kūlana hoʻouna like ʻole no nā paipu kila seamless a me nā paipu welded:

Paipu kila humuhumu ʻole (mokuʻāina N): ʻO ke kūlana N e pili ana i ke kūlana mālama maʻamau. Hoʻomaʻamaʻa ʻia nā paipu kila humuhumu ʻole ma mua o ka lawe ʻana e hoʻohui i ka microstructure o ka paipu kila, a laila e hoʻomaikaʻi ana i kona mau waiwai mechanical a me ka paʻakikī. Hiki i ka hoʻomaʻamaʻa ʻana ke hoʻopau i ke koʻikoʻi koena a hoʻomaikaʻi i ke kūpaʻa dimensional o ka paipu kila.

Paipu i hoʻopaʻa ʻia (M state): Pili ke kūlana M i ka mālama thermomechanical o ka paipu i hoʻopaʻa ʻia ma hope o ke kūkulu ʻana a me ka hoʻopaʻa ʻana. Ma o ka mālama thermomechanical, hoʻonui ʻia ka microstructure o ka paipu i hoʻopaʻa ʻia, hoʻomaikaʻi ʻia ka hana o ka wahi hoʻopaʻa ʻana, a hōʻoia ʻia ka ikaika a me ka hilinaʻi o ka paipu i hoʻopaʻa ʻia i ka wā e hoʻohana ai.

Kūlana API 5LHoʻākāka kikoʻī i ka haku mele kemika, nā waiwai mechanical, nā ʻano hana, nā koi nānā a me nā hoʻāʻo o nā paipu kila pipeline. ʻO ka hoʻokō ʻana o ke kūlana e hōʻoiaʻiʻo ana i ka palekana a me ka hilinaʻi o nā paipu kila pipeline i ka wā e lawe ana i ka ʻaila, ke kinoea kūlohelohe a me nā wai ʻē aʻe. ʻO ke koho ʻana i nā māka kūpono o nā paipu kila a me ke kūlana lawe ʻana e hiki ke hoʻokō i nā pono kikoʻī o nā papahana ʻenekinia like ʻole a hōʻoia i ka hana paʻa o ka ʻōnaehana pipeline.