Editing Grating (section)

== As filters ==
A grating covering a [[drain (plumbing)|drain]] (as illustrated) can be a collection of iron bars (the identical, elongated elements) held together (to ensure the bars are parallel and regularly spaced) by a lighter iron frame. Gratings over drains and [[air vent]]s are used as [[filter (chemistry)|filter]]s, to block movement of large solids (e.g. people) and to allow movement of liquids. A [[Register (air and heating)|register]] is a type of grating used in [[heating, ventilation, and air conditioning]], which transmits air, while stopping solid objects.
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File:Vindobona Hoher Markt-71.JPG|Grating - drain cover, [[ancient Roman architecture]] at [[Vindobona]], [[Austria]].
File:Montreal Sewer Cover.jpg|Sewer grating ([[manhole cover]]) that can be driven on despite letting water pass through
File:Tree grating, Washington, D. C. (3678939694).jpg|[[Tree grate|Tree grating]] that can be walked on despite letting water pass through
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