Hardware knowledge: structural characteristics of air duct ventilation butterfly valve

Structural characteristics of air duct ventilation butterfly valve

1. It is designed and manufactured with a new type of structure welded by a centerline disc plate and a short structure steel plate, with compact structure, light weight, easy installation, small flow resistance, large circulation, avoiding the influence of high temperature expansion, and light operation. There are no connecting rods, bolts, etc., so it works reliably and has a long service life. It can be installed in multiple stations and is not affected by the flow direction of the medium

Working principle:

The ventilation butterfly valve is driven by a motor to drive the actuator, so that the disc can rotate freely within a range of 90° to achieve the purpose of opening and closing or adjusting the flow of the medium. At present, fluorine-lined butterfly valves and rubber-lined butterfly valves, as a component used to realize on-off and flow control of piping systems, have been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower and so on. In the well-known butterfly valve technology, its sealing form mostly adopts a sealing structure, and the sealing material is rubber, polytetrafluoroethylene, etc. Due to the limitation of structural characteristics, it is not suitable for industries such as high temperature resistance, high pressure resistance, corrosion resistance, and wear resistance. An existing relatively advanced butterfly valve is a triple eccentric metal hard-sealed butterfly valve. The valve body and the valve seat are connected components, and the sealing surface layer of the valve seat is welded with temperature-resistant and corrosion-resistant alloy materials.

Multi-layer soft laminated sealing ring is fixed on the valve plate. Compared with the traditional butterfly valve, this kind of butterfly valve has high temperature resistance, light operation, no friction in opening and closing. When closing, the torque of the transmission mechanism increases to compensate for the sealing. Improve the sealing performance of the butterfly valve and the advantages of prolonging the service life. Ventilation butterfly valve classification construction and installation points 1), the installation position, height, and inlet and outlet directions must meet the design requirements. Note that the direction of the medium flow should be the same as the arrow direction marked on the valve body, and the connection should be firm and tight.

The valve must be visually inspected before installation. The nameplate of the valve should comply with the current national standard 'General Valve Marking' GB12220. For valves with a working pressure greater than 1.0 MPa and a cut-off function on the main pipe, the strength and tightness performance test should be carried out before installation, and the valve can be used only after it is qualified. During the strength test, the test pressure is 1.5 times the nominal pressure and the duration is not less than 5min. The valve housing and packing should be qualified without leakage. During the tightness test, the test pressure is 1.1 times the nominal pressure; the duration of the test meets the requirements of GB50243.