Even if the system design is perfect and the selected equipment is finely crafted, it is inevitable to carry out pneumatic conveying maintenance due to long-term equipment wear or sudden power outages in the powder and granular pneumatic conveying system; In order to facilitate maintenance, maintenance valves, also known as maintenance plug valves or maintenance gate valves, are often equipped in pneumatic conveying systems.

       The maintenance plug valve is a device used to cut off or roughly control the material flow during the material conveying process. In bag filters, it can generally be used in conjunction with the ash discharge valve at the outlet of the dust hopper of the dust collector. It has the function of preventing dust leakage from the ash hopper during the maintenance of the ash discharge valve, which is also the origin of the name of the maintenance plug valve.

       Manual plug valves are usually used for maintenance, and the commonly used types include blind plate manual plug valves and screw type manual plug valves.

       Blind plate manual plug valve: During normal operation of the dust collector, the flanges at both ends of the valve plate are blinded with blind plates, and the valve plate is not inserted into the valve and hung next to the manual plug valve. When the ash discharge valve malfunctions and needs to be repaired or replaced, the blind plate at one end of the plug valve can be opened, and the valve plate can be inserted to prevent the dust in the ash hopper from falling down, so as to facilitate the maintenance and replacement of the ash discharge valve. The blind plate manual plug-in valve consists of a valve body plate, an end plate (blind plate), a connecting flange, and a sealing gasket, and is a general steel plate welded component; Key installation points:

       1. The flange connection between the maintenance plug valve and the ash discharge valve must be sealed and not leak air;

       2. The installation of the maintenance plug valve should be directional, and the inlet of the plug valve should be on the same side as the maintenance platform of the ash hopper anti blocking device, in order to facilitate the operation of the plug valve;

       After the installation of the blind plate manual plug valve, the valve plate should be inserted smoothly and flexibly, and then the valve plate should be removed. The blind plate at the inlet end should be sealed properly;

       After the maintenance plug valve is installed, there is no need to operate it itself. Only when the ash hopper connected to it malfunctions, the end plate of the valve plate inlet should be removed for inserting the valve plate.

       Screw type manual plug valve is divided into round mouth screw type manual plug valve and square mouth screw type manual plug valve.