A、High Wall Drilling Pipe B、Heavy Wall Drilling Pipe C、Heavy weight Drilling Pipe D、High weight Drilling Pipe
A、FH=full hole B、REG=regular C、IF=internal flush D、RIH=Run in hole
A.電路負載過大 B.電流過大發(fā)熱 C.線路設(shè)計標準低 D.線路電壓過高