Flap valve

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(Mech.) a valve which opens and shuts upon one hinged side; a clack valve.

See also: Flap

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
At the Kirklees Council planning meeting that approved the proposal, the firm said it was considering installing a pumping facility and new 'flap valve' to prevent river water backing up and flooding under the arches.
Wienstein in 1899 reported caecal bascule as folding of caecum anterior to ascending colon producing a flap valve occlusion to caecal emptying.
[sup][1] The main purpose of these techniques is to provide the flap valve mechanism to temporarily close the ureter under increased intravesical pressure and also to provide a nonobstructed urinary flow toward the bladder with a normal ureteral peristalsis.
With the Plattco double flap valve, the object just lands on the flapper and passes through without disrupting the manufacturing process.
Following extensive testing, Camfil APC reports that the Stinger is the first U.S.-made explosion flap valve to be certified by an independent testing agency to comply with NFPA standards.
At University of Virginia Health Sciences Center PA-Banding revisited showed actuarial survival at 10 years of 92%.3 Novick et al reported Flap valve double patch closure of VSD having hospital deaths 7.7% and late mortality 8.9%.16 Afrasiabi et al reported valved-patch for VSD with PAH having early post-operative mortality of 12.5%.4 In our study we found mortality of 9% for two-stage closure of VSD following PA-Banding.
Officers discovered it was coming from a combined sewer outfall with a flap valve next to Pipe Bridge, which was believed to be part of the NWL sewer network.
A flap valve for instance is in general a very flat creation in contrary to an umbrella valve that requires some height.
The crease formed in the proximal colon forms a 'flap valve', occluding the lumen and causing massive caecal dilation.(1) Caecal bascule differs to the classical volvulus as it is not an axial torsion.
Through co-ordination between the borough and county councils and the Environment Agency, ditch pipework has been installed, a retaining wall raised, silt removed and a new flap valve installed.
"Unlike prior endoscopic treatments for reflux, the molding of the flap valve that holds back acid is expected to be much more robust and effective," the expert added.
If you are constantly pushing the lever and no water is siphoning into the pan, or you need to push the handle three to four times before it flushes, it means the diaphragm or flap valve has been worn or damaged and you will need to replace it.