Valve Casting Process Methods

Valve casting involves several methods used to create valves for various applications. Some common methods include:

1.Sand Casting

This is one of the oldest and most commonly used casting methods. It involves creating a mold made of sand into which molten metal is poured. Once the metal cools and solidifies, the sand mold is broken away to reveal the cast valve.

According to the different binders, it can be divided into Green Sand Casting, Resin Sand Casting, and Shell Molding.

Green Sand Casting: This is the most common method. Green sand, a mixture of sand, clay, water, and additives, is used to create molds. It's called "green" because the sand is moistened, not because of its color.

The produced sand mold does not require drying or hardening treatment. The sand mold has a certain wet strength, and the core and shell have good yielding properties, making it easy to clean and remove sand from castings.

Resin Sand Casting: In this method, resin is added to the sand mixture, making it stronger and allowing for more precise casting details.

The sand mold does not need to be dried, which shortens the production cycle and saves energy. Resin sand is easy to compact, has good collapsibility, and also easy to clean. The casting has high dimensional accuracy and excellent surface smoothness, which can greatly improve the quality of castings.

Shell Molding: This process involves creating a mold from a resin-coated sand that is cured to form a hard shell. It provides better surface finishes and dimensional accuracy.

2.Investment Casting

Also known as lost-wax casting, this method involves creating a wax pattern of the valve, coating it with a refractory material to form a mold, melting the wax out, and then pouring molten metal into the cavity. After solidification, the mold is broken to obtain the valve.

It’s advantages are as follows:

• The casting has high dimensional accuracy, smooth surface, and high appearance quality.
• It can cast parts with complex structure and shape that are difficult to process using other process
• Casting materials are not restricted, such as carbon steel, stainless steel, alloy steel, aluminum alloy, high-temperature alloy, and precious metals, especially alloy materials that are difficult to forge, weld, and cut.
• Good production flexibility and strong adaptability. It can be produced in large quantities and is also suitable for single piece or small batch production.