Chitoliro chachitsulo chopanda msoko API5L GRB ndi chitoliro chachitsulo chomwe chimagwiritsidwa ntchito kwambiri, chomwe chimagwiritsidwa ntchito kwambiri m'mafakitale amafuta, gasi ndi mafakitale ena. "API5L" yake ndi muyezo wopangidwa ndi American Petroleum Institute, ndipo "GRB" imasonyeza mtundu ndi mtundu wa chinthucho, chomwe nthawi zambiri chimagwiritsidwa ntchito pa mapaipi opanikizika. Ubwino wa mapaipi achitsulo chopanda msoko uli mu mawonekedwe awo abwino kwambiri a makina komanso kukana dzimbiri, ndipo amatha kugwira ntchito mokhazikika m'malo ovuta okhala ndi kutentha kwambiri komanso kuthamanga kwambiri.

Zigawo zazikulu za mankhwala a mapaipi achitsulo chosasunthika a API5L GRB ndi monga kaboni, manganese, sulfure, phosphorous, ndi zina zotero, ndipo ali ndi kuthekera kosinthasintha komanso kusinthasintha bwino pambuyo pa njira yotenthetsera kwambiri. Mtundu uwu wa chitoliro chachitsulo nthawi zambiri umagwiritsidwa ntchito kunyamula zakumwa ndi mpweya, makamaka pogwiritsira ntchito ndi kunyamula mafuta ndi gasi, kuti zitsimikizire kuti zili bwino komanso zogwira ntchito.

ASTM A53, ASTM A106ndiAPI 5LPali miyezo itatu yodziwika bwino ya chitoliro chachitsulo chopanda msoko, chilichonse choyenera kugwiritsidwa ntchito m'njira zosiyanasiyana.

Muyezo wa ASTM A53 umagwiritsidwa ntchito makamaka m'magawo monga magetsi, zomangamanga ndi mankhwala a petrochemical. Chitoliro chachitsulo cha muyezo uwu ndi choyenera malo otsika mphamvu ndi kutentha kochepa, ndipo nthawi zambiri chimagwiritsidwa ntchito kunyamula madzi, gasi ndi madzi ena. Chili ndi mphamvu yabwino komanso chotha kuwotcherera, ndipo chimagwiritsidwa ntchito popanga mapaipi osiyanasiyana ndi zida zomangira.

Muyezo wa ASTM A106 umayang'ana kwambiri kutentha kwambiri ndi kupanikizika kwakukulu ndipo ndi woyenera makampani amafuta ndi gasi. Mapaipi achitsulo osapindika a muyezo uwu amagwiritsidwa ntchito makamaka ponyamula nthunzi, madzi otentha ndi mafuta. Amatha kusunga mawonekedwe abwino a makina kutentha kwambiri kuti atsimikizire chitetezo ndi kukhazikika kwa payipi.

Muyezo wa API 5L wapangidwira makampani opanga mafuta ndi gasi ndipo ndi woyenera mapaipi otumizira mafuta amphamvu kwambiri. Mapaipi achitsulo opanda msoko omwe amakwaniritsa muyezo uwu ali ndi kukana dzimbiri komanso kukana kupanikizika, zomwe zimapangitsa kuti ntchito ikhale yotetezeka pamikhalidwe yovuta kwambiri. Mapaipi a API 5L nthawi zambiri amagwiritsidwa ntchito popanga ndi kunyamula mafuta ndi gasi kuti atsimikizire kuti madzi amatumizidwa bwino.

Miyezo itatu iyi ya mapaipi achitsulo opanda msoko ili ndi makhalidwe awoawo, ikukhudza zochitika zosiyanasiyana zogwiritsidwa ntchito kuyambira kupsinjika kochepa mpaka kupsinjika kwakukulu, kuyambira kutentha kochepa mpaka kutentha kwakukulu, kukwaniritsa zosowa zosiyanasiyana zamafakitale, ndikupereka chitsimikizo cha chitetezo ndi magwiridwe antchito.