open-air plant - overpressure
- open-air plant
- open-air space
- open-air swimming pool
- open-air theater
- open-air water power plant
- open-channel flow
- open-channel hydraulics
- open-channel storm drainage
- open-conduit drop
- open-end pipe pile
- open-end spanner
- open-end well
- open-end wrench
- open-ended wrench
- open-frame girder
- open-graded aggregate
- open-grained wood
- open-hearth steel
- open-hole drilling
- open-loop control system
- open-newel stair
- open-pan mixer
- open-pile braced structure
- open-riser stair
- open-spandrel arch bridge
- open-string staircase
- open-tank treatment
- open-textured
- open-textured asphaltic concrete
- open-web girder
- open-web joist
- open-web joist floor
- open-web steel joist
- open-web structure
- opener
- opening
- opening automatically
- opening between bars
- opening light
- opening of bids