How to check the appearance quality of malleable steel pipe fittings?

The molding mixture used in the common riser cavity of malleable steel pipe fittings is the same as the molding mixture used in the casting cavity. Therefore, the heat transfer rate of the molding mixture is the same, and the cooling rate is also the same. In order to ensure that the riser solidifies later than the casting, so as to ensure that the riser of the malleable steel pipe fitting has molten metal to feed the casting, it is necessary to make the riser have a large enough size. Apparently, this has just caused the increase of the door body and the decrease of the process yield.

The riser of malleable steel pipe fittings is a structure artificially set up in the mold to store molten metal, which is used to compensate for the possible shrinkage during the formation of the casting, to prevent the casting from shrinkage, shrinkage, and exhaust, slag collection, The role of guiding filling.

In order to increase the temperature of molten steel in the riser and prolong the solidification time, the heating agent, heat preservation agent and binder are prepared in a certain proportion, and then made into a heating sleeve, which is placed on the riser of the casting to improve the feeding effect of the riser. The similar riser is called "heating riser", referred to as "heating riser". The heating sleeve riser has a remarkable feeding effect and is easy to operate, so it is widely used in factories.

Malleable steel pipe fittings are pipe fittings made of malleable steel. Since the malleable steel pipe fittings are made of iron, they are prone to rust when exposed to the air. In particular, our malleable steel pipe fittings are mainly used for fire protection and water supply projects. The pipe fittings are exposed to humid environment for a long time and are more prone to rust. Therefore, the malleable steel pipe fittings need to be treated with anti-rust treatment on its surface. The surface anti-rust treatment of malleable steel pipe fittings is generally divided into two types: hot-dip galvanizing and cold-dip galvanizing. Hot-dip galvanizing refers to a galvanizing treatment method in which the pipe fittings are immersed in a zinc solution melted at a high temperature of 700-800 degrees, so that the surface of the pipe fittings is covered with a layer of zinc. Cold galvanizing is also called electro-galvanizing. Its principle is to rely on electrophoresis to transfer and attach the zinc hanging on the anode to the surface of the pipe hanging on the cathode, thereby forming a thin and uniform zinc layer.

Since malleable steel pipe fittings are connected by thread, it can also be called thread pipe fittings (thread pipe fittings). However, although most of the galvanized pipe fittings refer to malleable steel pipe fittings, since some welded pipe fittings or other iron pipe fittings are also galvanized on the surface, strictly speaking, galvanized pipe fittings are not equal to malleable steel pipe fittings. The same is true for threaded pipe fittings. Some iron pipes and even plastic pipes are also connected by threaded pipes, but their material is not malleable steel.