Lower limit adjustment device for wedge gate valve

Abstract

The invention relates to an executing mechanism lower limiting adjusting device for a wedge-type gate valve. The device comprises a connecting support, a limiting retaining plate, adjusting bolts and check nuts. The device is characterized in that threaded holes for the adjusting bolts are formed at the bottom of the connecting support, the limiting retaining plate is mounted on a valve rod through screw-thread fit and fastened at the lower end of a connecting Haff, the adjusting bolts are mounted on the connecting support through screw-thread fit, the heads of the bolts are jacked and pressed below the limiting retaining plate, the other ends of the bolts penetrate a middle-head connecting flange of the wedge-type gate valve, and the check nuts and the adjusting bolts are fastened on the connecting support in a threaded connection manner. By the device, the phenomenon that the wedge-type gate valve cannot be normally opened due to the fact that the wedge-type gate valve is closed too tightly is avoided; the device is simple in structure, reliable and practical, stability in normal opening and closing of the valve is guaranteed, a sealing face of a gate plate and a valve seat of the wedge-type gate valve can be effectively protected, maintenance and repair frequency of the valve is lowered, and service life is prolonged.

Description

technical field [0001] The invention relates to a device for adjusting the lower limit of an actuator, in particular to a device for adjusting the lower limit of an actuator for a wedge gate valve, which belongs to the field of fluid control valves. Background technique [0002] Gate valves are divided into single-gate gate valves, double-gate gate valves and elastic gate valves according to their structural principles. They are the most common type of all valves and are the first choice for opening and closing devices in general main and branch pipelines. accounted for more than 40% of the total. Most gate valves adopt wedge structure, and its sealing principle is: under the action of external force provided by the actuator, etc., the valve stem drives the two sealing surfaces on the wedge gate plate and the two sealing surfaces on the valve body to be tightly combined when wedging. To achieve sealing, the purpose of using the wedge plate is to increase the auxiliary seali...

AI Technical Summary

Problems solved by technology

[0003] In practical applications, under the action of the external force provided by the actuator, the gate valve gate moves downward, and the wedge structure is easy to cause excessive closing due to excessive driving force. Due to the deformation of the sealing parts, the instantaneous starting force required for opening is several times higher than that of normal operation, and the valve cannot be opened or the starting lag often occurs.

This not only affects the normal switching needs, but also aggravates the wear of the sealing surface, causing valve leakage and greatly shortening the service life of the valve

Images