oil drain opening

oil pan drain opening

uppermost case drain opening

drain plug opening

at-the-opening (opening only) order

weeper drain；weep drain；drainage ditch；drain ditch

drain castinghollow casting drain tile

Opening-Closing-Opening Test

reform and opening-up; reform and opening to the outside world

‘zero’ drain

acid drain cleaners

active drain hold-up tank

active drain tank

active-effluent drain pipe

actuator oil drain

aft water drain mast

after drain line

aftercooler air chamber drain

aftercooler drain