A door, usually small, which is provided through a finished construction, as into a duct, through a ceiling, behind a wall, in a large piece of mechanical equipment, etc.; used to provide a means of inspection of equipment or services housed within.
A door, usually small, which is provided through a finished construction, as into a duct, through a ceiling, behind a wall, in a large piece of mechanical equipment, etc.; used to provide a means of inspection of equipment or services housed within.