Russian ⇄ English

свободное сечение stresses
auto.	clear opening (напр., клапана)
Makarov.	free cross-section
mech.eng., obs.	clear opening (трубы, клапана и т.д.)
mil.	clear opening (трубы, клапана)
mil., arm.veh.	clear opening (клапана)
mining.	effective section; clear opening (трубы)
oil	free area (трубы, колонны)
railw.	clear opening (напр., трубы, клапана и пр.)
transp.	clear opening (напр. клапана)

свободное сечение: 24 phrases in 13 subjects

Astronautics	5
Automated equipment	1
Electronics	2
Gas processing plants	1
Makarov	3
Mechanic engineering	3
Metallurgy	1
Mining	3
Nanotechnology	1
Oil / petroleum	1
Oil and gas technology	1
Road works	1
Seismology	1