Found 1 items, similar to Air valve.
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Definition: Air valve
, n. [L. valva the leaf, fold, or valve of a door:
cf. F. valve.]
1. A door; especially, one of a pair of folding doors, or one
of the leaves of such a door.
Swift through the valves the visionary fair
Heavily closed, . . . the valves of the barn doors.
2. A lid, plug, or cover, applied to an aperture so that by
its movement, as by swinging, lifting and falling,
sliding, turning, or the like, it will open or close the
aperture to permit or prevent passage, as of a fluid.
Note: A valve may act automatically so as to be opened by the
effort of a fluid to pass in one direction, and closed
by the effort to pass in the other direction, as a
clack valve; or it may be opened or closed by hand or
by mechanism, as a screw valve, or a slide valve.
3. (Anat.) One or more membranous partitions, flaps, or
folds, which permit the passage of the contents of a
vessel or cavity in one direction, but stop or retard the
flow in the opposite direction; as, the ileocolic, mitral,
and semilunar valves.
(a) One of the pieces into which a capsule naturally
separates when it bursts.
(b) One of the two similar portions of the shell of a
(c) A small portion of certain anthers, which opens like a
trapdoor to allow the pollen to escape, as in the
5. (Zo["o]l.) One of the pieces or divisions of bivalve or
, Ball valve
, Check valve
, etc. See under
, a kind of balance valve usually
consisting of a movable, open-ended, turban-shaped shell
provided with two faces of nearly equal diameters, one
above another, which rest upon two corresponding seats
when the valve is closed.
(a) A balance valve. See under Balance
(b) A valve for permitting air, steam, water, etc., to
pass into or out of a chamber so as to establish or
maintain equal pressure within and without.
(Mach.), a chamber in which a valve works;
especially (Steam Engine), the steam chest; -- called in
England valve box
, and valve casing
. See Steam chest
, under Steam
(Mach.), that part of the surface of a valve
which comes in contact with the valve seat
, or Valve motion
(Steam Engine), the system of
parts by which motion is given to the valve or valves for
the distribution of steam in the cylinder. For an
illustration of one form of valve gear, see Link motion
(a) The fixed surface on which a valve rests or against
which it presses.
(b) A part or piece on which such a surface is formed.
(Mach.), a rod attached to a valve, for moving
(Mach.), a strap embracing a slide valve and
connecting it to the valve stem.
([^a]r), n. [OE. air, eir, F. air, L. a["e]r, fr. Gr.
'ah`r, air, mist, for 'a[digamma]hr, fr. root 'a[digamma] to
blow, breathe, probably akin to E. wind. In sense 10 the
French has taking a meaning fr. It. aria atmosphere, air, fr.
the same Latin word; and in senses 11, 12, 13 the French
meaning is either fr. L. aria, or due to confusion with F.
aire, in an older sense of origin, descent. Cf. A["e]ry
1. The fluid which we breathe, and which surrounds the earth;
the atmosphere. It is invisible, inodorous, insipid,
transparent, compressible, elastic, and ponderable.
Note: By the ancient philosophers, air was regarded as an
element; but modern science has shown that it is
essentially a mixture of oxygen and nitrogen, with a
small amount of carbon dioxide, the average proportions
being, by volume: oxygen, 20.96 per cent.; nitrogen,
79.00 per cent.; carbon dioxide, 0.04 per cent. These
proportions are subject to a very slight variability.
Air also always contains some vapor of water.
2. Symbolically: Something unsubstantial, light, or volatile.
“Charm ache with air.”
He was still all air and fire. [Air and fire being
the finer and quicker elements as opposed to earth and
3. A particular state of the atmosphere, as respects heat,
cold, moisture, etc., or as affecting the sensations; as,
a smoky air, a damp air, the morning air, etc.
4. Any a["e]riform body; a gas; as, oxygen was formerly
called vital air. [Obs.]
5. Air in motion; a light breeze; a gentle wind.
Let vernal airs through trembling osiers play.
6. Odoriferous or contaminated air.
7. That which surrounds and influences.
The keen, the wholesome air of poverty.
8. Utterance abroad; publicity; vent.
You gave it air before me. --Dryden.
9. Intelligence; information. [Obs.] --Bacon.
(a) A musical idea, or motive, rhythmically developed in
consecutive single tones, so as to form a symmetrical
and balanced whole, which may be sung by a single
voice to the stanzas of a hymn or song, or even to
plain prose, or played upon an instrument; a melody;
a tune; an aria.
(b) In harmonized chorals, psalmody, part songs, etc.,
the part which bears the tune or melody -- in modern
harmony usually the upper part -- is sometimes called
11. The peculiar look, appearance, and bearing of a person;
mien; demeanor; as, the air of a youth; a heavy air; a
lofty air. “His very air.”
12. Peculiar appearance; apparent character; semblance;
It was communicated with the air of a secret.
12. pl. An artificial or affected manner; show of pride or
vanity; haughtiness; as, it is said of a person, he puts
on airs. --Thackeray.
(a) The representation or reproduction of the effect of
the atmospheric medium through which every object in
nature is viewed. --New Am. Cyc.
(b) Carriage; attitude; action; movement; as, the head of
that portrait has a good air. --Fairholt.
15. (Man.) The artificial motion or carriage of a horse.
Note: Air is much used adjectively or as the first part of a
compound term. In most cases it might be written
indifferently, as a separate limiting word, or as the
first element of the compound term, with or without the
hyphen; as, air bladder, air-bladder, or airbladder;
air cell, air-cell, or aircell; air-pump, or airpump.
. See Balloon
(a) An apparatus for the application of air to the body.
(b) An arrangement for drying substances in air of any
. See Castle in the air
, under Castle
, a machine for compressing air to be used as
a motive power.
, a passage for air in a mine.
, an air-tight cushion which can be inflated;
also, a device for arresting motion without shock by
, a contrivance for producing a jet of water by
the force of compressed air.
, a furnace which depends on a natural draft and
not on blast.
, a straight line; a bee line. Hence
, adj.; as, air-line road.
(Hydr. Engin.), an intermediate chamber between
the outer air and the compressed-air chamber of a
pneumatic caisson. --Knight.
(Nav.), a scuttle or porthole in a ship to admit
, a spring in which the elasticity of air is
, a form of thermometer in which the
contraction and expansion of air is made to measure
changes of temperature.
, a contrivance for shutting off foul air or gas
from drains, sewers, etc.; a stench trap.
, a pipe or shaft for conducting foul or heated
air from a room.
, a valve to regulate the admission or egress of
air; esp. a valve which opens inwardly in a steam boiler
and allows air to enter.
, a passage for a current of air; as the air way of
an air pump; an air way in a mine.
In the air
(a) Prevalent without traceable origin or authority, as
(b) Not in a fixed or stable position; unsettled.
(c) (Mil.) Unsupported and liable to be turned or taken
in flank; as, the army had its wing in the air.
on the air
, currently transmitting; live; -- used of radio
and television broadcasts, to indicate that the images and
sounds being picked up by cameras and microphones are
being broadcast at the present moment.
Note: In call-in programs where individuals outside a radio
or television studio have telephoned into the station,
when their voice is being directly broadcast, the host
of the program commonly states “You're on the air.”
as a warning that the conversation is not private.
To take air
, to be divulged; to be made public.
To take the air
, to go abroad; to walk or ride out.