Pattern, gating and riser combination and size control of lost foam casting for stainless steel valves

The gating system of stainless steel valve is designed with a variety of pouring methods, such as bottom injection, top injection, step injection and side injection. It should be reasonably selected and designed according to the structural characteristics of the casting. The sectional area of stainless steel valve gating system is larger than that of other alloy lost foam casting gating systems, and the inner sprue is generally set at the wall thickness of the casting to ensure the feeding effect during pressurization.

According to the characteristics of lost foam casting, it is easy to cause disorder when pouring the stainless steel water of the valve, and the fluidity of the stainless steel of the valve is poor, so that the metal liquid is often prone to insufficient pouring or cold shut defects at the farthest part of the mold filling. In order to ensure that the casting does not have defects, the pouring temperature should be appropriately increased, the gate cross-sectional area and the height of metal indenter should be increased.

According to the structural characteristics of the valve body, in order to avoid loose defects at the wall thickness, the gating system of the stainless steel valve adopts the bottom pouring type. The inner sprue is set at the wall thickness positions of the two flange plates of the valve body, with the section size of 10 mm x 35 mm, the diameter of the transverse sprue and auxiliary sprue is 40 mm x 30 mm, and the diameter of the direct sprue is φ 50mm, consisting of 4 patterns, as shown in the figure.