Goobaha warshadaha ee maanta, tuubooyinka birta ayaa loo adeegsadaa codsiyo kala duwan iyo noocyo badan, kuwaas oo dhalaalaya. Waxaa ka mid ah, ASTM A106/A53/API 5L GR.B birta fasalka B, sida qalab bir ah oo muhiim ah, waxaa door biday injineerada iyo soosaarayaasha si ay u fiican p ...
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