How is the feeding channel of malleable steel pipe fittings and steel castings formed?

With the rapid development of my country's economy, the demand for malleable cast iron pipeline connectors (commonly known as malleable steel pipe fittings) for water, gas and oil circuits is increasing day by day, and the requirements for its quality are also getting higher and higher.

The applicability of malleable steel pipe fittings to the size of castings. Unlike magnetic casting, castings produced by negative pressure solid casting are limited by the size of the magnetic pole spacing. As long as the size of the magnetic pole is fixed, the size of the sand box is also determined. It is almost impossible to cast box-sized castings, and it is generally only suitable for pouring small pieces of one hundred and ten kilograms. Negative pressure solid indium casting is much more applicable to the size of castings. Sand boxes of different sizes can be placed on the same vibrating table, so castings of various sizes can be produced very conveniently.

However, due to the low strength of the foam plastic model, and the fact that the filling cannot be absolutely uniform during the embedding operation, the model is easily deformed, which brings certain difficulties to casting large, narrow and thin castings. Therefore, considering the convenience of operation and the existing technology level, negative pressure compact casting is suitable for castings with castings below 2t (especially 500kg) and with a wall thickness greater than 4mm.

Spinning of malleable steel pipe fittings is generally used to process carbon steel with a thickness of less than 1.5-2mm, or non-ferrous metal parts with a thickness of less than 3mm. For thicker parts, heated spinning must be used. Now introduce the spinning process of several typical parts.

There are two types of head spinning, vertical and horizontal. Large heads are generally spun on a vertical spinning machine. Most of this spinning machine is used in conjunction with an ordinary press. After the dome is pre-pressed by the ordinary press, the flanging is then spun on the spinning machine. Domes and flanges can also be pressed directly on the spinning machine.

The heating of the fillet part of the head is carried out on the heating furnace, and the flame heater is ignited for local heating. Since the sealing head rotates continuously around the main shaft, the heating of the sealing head in the circumferential direction is uniform. Spinning depends on the function of the outer roller, the position of the outer roller is adjusted by the horizontal axis and the vertical axis to adjust the position of the outer roller in the horizontal and vertical directions, and the outer roller itself can also be changed freely, so the outer roller is always in the spinning process Can make good contact with the head.

The shape of the spinning head is accurate, basically without ovality and wrinkles, and the size is relatively small. Operations such as edge trimming and beveling can also be performed on the spinning machine.