Spec Grades API 5CT J55、K55、L80、N80-1、N80Q、P110 API 5DP PSL1 、PSL2 、PSL3
spekulim
notat
API 5CT
J55, K55, L80, N80-1, N80Q, marrëse-dhënëse P110
API 5DP
PSL1 , PSL2 , PSL3