The solidified metal component is then removed from its mold. Where the mold is sand based, this can be done by shaking or tumbling. This frees the casting from the sand, which is still attached to the metal runners and gates - which are the channels through which the molten metal traveled to reach the component itself.
Degating is the removal of the heads, runners, gates, and risers from the casting. Runners, gates, and risers may be removed using cutting torches, band saws or ceramic cutoff blades. For some metal types, and with some gating system designs, the sprue, runners and gates can be removed by breaking them away from the casting with a hammer or specially designed knockout machinery. Risers must usually be removed using a cutting method ..
http://en.wikipedia.org/wiki/Foundry

Le parachèvement est l’opération de finition d’une pièce (sciage ou découpe du système d'alimentation, meulage, ébavurage, ...), quel que soit son mode de fabrication, avant sa mise en fonction définitive ou avant de passer à une autre étape de fabrication.
http://fr.wikipedia.org/wiki/Fonderie

Gating system: The network of connected channels that deliver the molten material to the mold cavities.
Pouring cup or pouring basin: The part of the gating system that receives the molten material from the pouring vessel.
Sprue: The pouring cup attaches to the sprue, which is the vertical part of the gating system. The other end of the sprue attaches to the runners.
Runners: The horizontal portion of the gating system that connects the sprues to the gates.
Gates: The controlled entrances from the runners into the mold cavities.
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The gates are usually attached to the thickest part of the casting to assist in controlling shrinkage. In especially large castings multiple gates or runners may be required to introduce metal to more than one point in the mold cavity.
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The gating system may also be designed to trap dross. One method is to take advantage of the fact that some dross has a lower density than the base material so it floats to the top of the gating system. Therefore long flat runners with gates that exit from the bottom of the runners can trap dross in the runners; note that long flat runners will cool the material more rapidly than round or square runners. For materials where the dross is a similar density to the base material, such as aluminium, runner extensions and runner wells can be advantageous
http://en.wikipedia.org/wiki/Casting_(metalworking)

6.3.2 Système d’injection
Ce système est composé d'un tube plongeur et d'une buse appelée col d'alimentation qui assure la liaison entre le tube et le moule. En outre, la séparation entre métal liquide et solide se fait dans ce col. Le tube est une pièce très sollicitée thermiquement et chimiquement. Pour des raisons d'économie on a abandonné les matières très réfractaires mais chères. Les tubes sont en fonte grise moulée ou en acier étiré. Ils sont protégés, dans le cas de coulée d’aluminium, toutes les 10h à 20h de fonctionnement, extérieurement et intérieurement. La partie inférieure du tube est souvent amovible, car c'est la zone la plus sollicitée.
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- Moulage de plusieurs pièces avec un seul canal d’alimentation central
http://manu.nmz.ifrance.com/TRAVAUX/moulage.pdf

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Note added at 1 hr (2010-03-23 18:05:37 GMT)
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Correction d'erreur de frappe:
tubes horizontales courts ou longues optimisés et fabriqué sur démande

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Note added at 1 day2 hrs (2010-03-24 18:58:57 GMT)
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This was shown on the scheme, see
http://en.wikipedia.org/wiki/Casting_(metalworking)
(You may have to click on the link "Did you mean: Casting (metalworking)" first to see the complete article.