Pilot-operated double-spool split-range adjusting valve

Abstract

The invention relates to a pilot-operated double-spool split-range adjusting valve which is characterized in that a valve base is arranged in a valve body, a Teflon valve base is arranged on the valve base, a main spool is assembled on the Teflon valve base to form flexible sealing, a valve rod is integrally connected with a pilot-operated spool, and the valve rod and a compression spring are assembled in an inner cavity of the main spool. A first Teflon guide tape is arranged in a trough of the pilot-operated spool, a thrust ring is used for being connected with the main spool, and the sealing surface of the pilot-operated spool is attached to the sealing surface in the inner cavity of the main spool. A noise reduction sleeve and a balancing ring base are sequentially arranged on the valve base. A stuffing assembly is assembled in an upper cover stuffing box, and an upper cover is fixed on the valve body. By adopting the pilot-operated double-spool split-range adjusting valve, a bypass parallel-connection valve is not used for flow adjusting, and accordingly the use quantity of the valves is saved. The pilot-operated spool can meet requirement of equal percentage accurate adjusting under small opening, and the main spool can meet requirement of equal percentage accurate adjusting under large opening and achieve the function of media large flow backflow cutting in the pipeline system failure state. Flow of the pilot-operated double-spool split-range adjusting valve can be adjusted accurately and the pilot-operated double-spool split-range adjusting valve can save pipe distribution space and reduce use cost of clients.

Description

technical field [0001] The invention relates to a pilot-operated, split-range regulating valve with double spool adjustment. The valve has equal-percentage precise adjustment for small openings within the stroke range and equal-percentages for large openings. The utility model can realize the function of cutting off the backflow of the medium in the pipeline with a large flow rate, and belongs to the technical field of fluid control regulating valves. Background technique [0002] The medium in the pipeline used by this valve is nitrogen, the temperature is 40°C, the pre-valve pressure is 2.8MPaA during normal operation, the post-valve pressure is 0.54 MPaA, and the adjusted pressure difference is 2.26MPa. When the valve is working normally, the flow rate needs to meet the 400NM during the start-up phase 3 / H continuously adjustable, 30000 NM for smooth operation 3 / H is continuously adjustable; when the pipeline system fails, the valve needs to meet the maximum return flo...

AI Technical Summary

Problems solved by technology

According to the above working conditions, the existing control valve cannot meet its actual requirements, because the normal adjustment opening of the existing control valve is between 30% and 70%, the adjustable ratio is 30:1, and the dead zone is large; and this The diameter of the pipeline is DN300. In the past, the pressure-reducing sleeve valve of DN300 was installed. Due to factors such as pipeline vibration and scouring, it will not be able to achieve the precise adjustment of the small opening flow rate during the start-up phase.

In addition, the leakage of the existing valves has far exceeded the regulated flow during the start-up stage required by the working conditions; at the same time, the existing pilot valves only have the function of small opening pressure relief and large opening adjustment, which is different from the start-up required by this working condition. Stage small opening adjustment to stabilize the system pressure, large opening adjustment, the technical requirements for large flow backflow when the system fails do not meet

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