• synonyms

flap valve

  1. clack valve.
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Origin of flap valve

First recorded in 1865–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for flap valve

Historical Examples

  • At o is a delivery valve, opening outwards, which is often a ball-valve but sometimes a flap-valve.

    Encyclopaedia Britannica, 11th Edition, Volume 14, Slice 1


  • A flap-valve nailed over a scupper-hole, serving to keep water from getting in, yet letting it out.

    The Sailor's Word-Book

    William Henry Smyth

  • This blow-hole has a flap-valve, which the noxious blast opens, as often as it passes out.

    De Re Metallica

    Georgius Agricola