Mechanical valve needle type valve needle rod bending degree correction method
One, Introduction
Valves play a key role in industrial production, not only can they control the flow of fluids, but they can also protect equipment and pipeline systems to a certain extent. Among them, needle valves as a common control valve, their working principle is to control the flow of fluids by the up and down movement of the needle valve plate in the valve body. The needle rod, as a key component of the needle valve, its bending degree directly affects the normal operation of the valve. The correction of needle rod bending degree is of great significance to ensure the normal operation of the valve and extend the service life of the valve. This article will introduce the methods of needle rod bending degree correction.
Two, Correction methods of needle rod bending degree
Mechanical correction method
Mechanical correction method is to correct the bending degree of the needle rod through a mechanical device, common mechanical correction devices include mechanical correction machine, hydraulic correction machine, etc. The correction principle is to apply correction force to the bent needle rod through the mechanical device to restore its original shape. The operation of mechanical correction method is simple and the correction effect is stable, but it requires a large correction force, and the correction difficulty and correction force requirements are higher for needle rods with large bending degrees.
Thermal correction method
Thermal correction method is to soften the needle rod by heating, and then use correction force to correct its bending degree to normal. The advantages of thermal correction method are small correction force and convenient operation, but it requires heating the needle rod, and there are certain safety hazards during the operation process. Moreover, the needle rod needs to be cooled to prevent deformation.
Cold correction method
Cold correction method is to apply correction force to the bent needle rod through a cold correction machine, so that it can return to its original shape. The advantages of cold correction method are simple operation, no need to heat the needle rod, and small correction force, without safety hazards during the operation process. However, cold correction method requires a correction machine, and for needle rods with large bending degrees, higher correction force requirements and greater correction difficulty exist.
Three, Matters needing attention in needle rod bending degree correction
When correcting the needle rod bending degree, the following points should be noted:
Ensure that the correction force is moderate, as too much or too little force will affect the correction effect.
Ensure that the temperature of the needle rod during the correction process is appropriate, as too high or too low temperatures will affect the correction effect.
Ensure that the shape of the needle rod is stable during the correction process, to avoid changes in the shape of the needle rod due to factors such as temperature change and pressure change.
Ensure that the surface of the corrected needle rod is smooth, without cracks, deformation, and other defects.
Four, Conclusion
The correction of the needle rod bending degree is of great significance to ensure the normal operation of the valve and extend the service life of the valve. The main methods of needle rod bending degree correction include mechanical correction, thermal correction, and cold correction. When correcting the needle rod bending degree, attention should be paid to the correction force, correction temperature, stability of the needle rod shape, and smoothness of the surface of the corrected needle rod to ensure the correction effect.