What are the benefits of ductile iron ball valves
date:2024-05-09 10:39
As one of the alternative steel materials, ductile iron ball valves were discovered by humans in 1949 and quickly adopted by valve manufacturing enterprises. Steel with a carbon content of less than 0.3%, cast iron and ductile iron with a carbon content of at least 3%. The existence of graphite flake structure without forming low carbon content steelmaking as free carbon. Carbon is the natural form of free graphite flakes in iron. In ductile iron, it undergoes special treatment to become small flakes of graphite balls. This enables the ball to have better physical properties compared to the improved ratio of ductile cast iron and steel. This is the spherical microstructure of carbon, which has better ductility and impact resistance, and there is no ductility table for the cast iron on the inner side of the sheet.
Obtained from a ductile ferrite matrix, the load pressure of ductile iron parts is during the intermediate annealing cycle of ferrite, with a spherical structure within the toughness of cast iron. Post treatment can easily eliminate the phenomenon of internal cracks in the graphite during valve manufacturing. In the microscopic photos of ductile iron, it can be seen that the graphite balls terminate after the cracks in the parade. In the ductile iron industry, these so-called graphite balls are crack terminators because they have the ability to prevent damage. Compared to cast iron, ductile iron has advantages in strength. The tensile strength of ductile iron is 60K, while the tensile strength of cast iron is only 31K. The yield strength of ductile iron is 40K, while iron does not show yield strength and fracture occurrence. Strength ductile iron - the cost ratio is much better than cast iron.
Ductile iron ball valves should generally be installed horizontally in pipelines. Ball valves are divided into pneumatic ball valves, electric ball valves, and manual ball valves according to their driving methods.
Daily maintenance of ductile iron ball valves:
Having a long service life and maintenance free period will depend on the following factors: normal working conditions, maintaining a harmonious temperature/pressure ratio, and reasonable corrosion data
When the ball valve is closed, there is still pressurized fluid inside the valve body
Before maintenance: Release the pipeline pressure and keep the valve in the open position; Disconnect the power or air source; Detach the actuator from the bracket
It is necessary to first verify that the upstream and downstream pipelines of the ball valve have been depressurized before proceeding with disassembly and disassembly operations
When disassembling and reassembling, care must be taken to prevent damage to the sealing surface of the parts, especially non-metallic parts. When removing the O-ring, special tools should be used
The bolts on the flange must be tightened symmetrically, gradually, and evenly during assembly
