Wuxi Dongao Nonferrous Casting Co., Ltd.
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Precautions on casting of Valve Castings
- Oct 19, 2017 -

Valve castings using EPC / resin sand casting, when the valve castings in the casting should pay attention to the following:

First, at the beginning of the pouring, especially in the moment when the molten metal is in contact with the foam, the static pressure head of the molten metal is less than the polystyrene decomposition when the gate is not filled or just started pouring due to the large amount of gas produced by the gasification of the molding material Product gas pressure, too fast pouring easy to produce choking fire phenomenon, so that the molten metal splash. In order to avoid this phenomenon, in the beginning of the pouring can take the first stream of slow pouring method, to be pouring system is filled with metal liquid, you can increase the casting speed as soon as possible, but the gate cup filled with metal Spillover as a criterion. At the end of the casting, when the metal liquid reaches the top of the mold or the riser root, it should be slightly wrapped to keep the metal rise steadily and not to cause the molten metal to come out of the riser.

Second, as far as possible selection of the end of the package. Bottom injection of metal liquid heat loss is small, pressure head, pouring speed, slag floating in the metal liquid on the surface, pouring molten steel is relatively clean. By the equipment conditions, for some of the requirements are not high or generally small machine tool castings can also be used subcontract pouring.

Third, the pouring process can not be interrupted. When pouring the valve castings, it is necessary to keep the molten metal continuously until the mold is fully filled. Otherwise, it is easy to pause the casting caused by the entire plane of the cold barrier defects.