Forged Brass Gate Valve

Forged Brass Gate Valve ART.N10131004 is our best seller gate valve, mainly used for the circulation and cutting of pipeline media such as water, steam, gas and oil, flow and pressure adjustment, and flow direction change, etc.

The valve body is the main part and most important for brass gate valve function, and the gate valve body is the most complex structure among many types of valves.

Red forging  is also called hot forging. In the brass gate valve manufacturing industry, everyone is more accustomed to the name "red forging", which is a hot extrusion process that performs less and no cutting on metal materials. After the brass material is heated to a certain temperature, it is plastically deformed in the cavity of the red forging die under the pressure of the reciprocating movement of the stamping equipment to form a blank of the required shape and size. Under normal circumstances, it can be done at one time, and can perform brass gate valve body multi-directional de-molding action at one time.

Different from the previous method of controlling the composition ratio in the brass material smelting used in foundry and casting, the red punch can directly use ordinary round bar materials, and the blanks with large deformation variables can also be used in special-shaped materials for better molding effects. There are three types of brass rods for brass gate valve: continuous casting rods, hot-rolled rods and extruded rods. Among them, the extruded rods have the best performance and relatively high cost; the continuous casting rods have low density relative to copper and have grain gaps, but they have advantages in price. After continuous practice, the brass bar grades that can be used for red forging have a wide range of grades. The copper content is generally required to be higher than 55%, otherwise the plasticity and forgeability of the raw material will be reduced, and the plasticity and mechanical properties of the formed blank will drop sharply, which will easily cause cracks and fractures. Containing less than 3.5% lead in the bar material is conducive to the improvement of the cutting performance of the valve body blank in the next step of gold processing. In lead-free or less-lead bar materials, the substitution of elements such as silicon and bismuth will be adopted to increase the cutting performance. If the lead content exceeds 3.5%, the plasticity and mechanical properties of the formed blank will also decrease. Generally, it contains a small amount of aluminum, which will help improve the fluidity of the material. However, if the content of aluminum is higher than 0.35%, the red stamping parts of the forged brass gate valve body will be easily brittle, and even cracks will occur during the installation and use of the valve. The most widely used and superior grades are HPb57-3, HPb59-1 and HPb60-2.

At present, there are also electric induction furnaces for heating, but the best effect is the automatic gas heating furnace, which can automatically control the temperature, heat the sections uniformly, and can automatically detect and screen the standard sections. The performance of the forged brass gate valve is also getting better.

The purpose of segment heating is to improve the plasticity of the alloy, reduce the resistance to deformation, and also make the internal molecular structure of the alloy more uniform, so that the stamping parts can have a good linear structure and mechanical properties. The temperature range of forged brass gate valve refers to the temperature at which the segment is extruded from the beginning to the end of the extrusion. The higher the temperature, the better the extrusion, but too high a temperature will cause oxide scale on the metal surface, or even over-burning.

Since there is a certain amount of heat loss after the segment is heated to enter the mold cavity, and a certain temperature is also generated during the high-speed stamping process, the heating temperature of the segment is generally slightly higher than the red forging temperature range. The heating temperature varies according to the characteristics of different material grades, and is usually 130-200°C lower than the melting point of the metal. The red forging temperature of HPb57-3 brass and CW617N brass is 650~750℃, and the red forging temperature range of HPb60-2 is 670~730℃.

1. Before the red forging of forged brass gate valves, the mold cavity should be preheated, and the temperature should be controlled at about 250~300℃ to reduce the scrap of cold mold.

2. The joint surface between the various parts of the mold should be within the design tolerance range to ensure a good sliding state during movement.

3. In addition to reasonable mold material grades, module blanks need to be upset repeatedly, and heat treatment before mold use is also very important.

4. Inlays and cores should be regularly repaired and repaired. The cavity of the inserts is designed according to the tolerance of the valve body shape. During the mold repair process of forged brass gate valves   , the size of the large cavity will be increased, and the flash between the inserts should be considered.

5. The rigidity of the forged brass gate valve is guaranteed, especially for the medium core. Once deformed, the machining allowance must be increased if the core is deformed, and the blank will be scrapped if the core is heavy.

6. After a certain modulus is produced, it is necessary to spray the mold release machine on the cavity in time to ensure the smooth demolding of the blank.