1.Selection of gate valve body blank
This method is suitable for the high pressure self tight seal gate valve body blank and the gate valve body blank with the cylinder middle flange structure.
2.Blank machining of cylinder valve body with middle cavity block valve body
(1) Process the sealing bevels on both sides of the gate valve body process the sealing bevels on both sides of the gate valve body to form two seat ring holes concentric with the flow passage of the valve body, respectively place the support plate and the plug plate, place the overlay sealing surface on one side of the plug plate, the processing area is as shown in a in the figure, and the red dotted line represents the rough area of the original gate valve body.
(2) Machine the upper end of the seat rings on both sides of the valve body to obtain the two circular planes by machining the dimpling two circular holes, and the machining area is shown in B in the figure.
(3) Weld the screw block at the two spot facer holes B of the valve body respectively to make the valve plug in normal working condition, and compress the guide ring through the bolt and the pressing strip, as shown in C and D in the figure.
(4) The middle cavity is sealed with flange gasket.
3.Self tightening sealing gate valve body rough machining block valve body
In addition to wood sealing, other processing methods of high-pressure gate valve body blanks are the same as that of cylinder-shaped valve body. The high-pressure self tightening sealing block valve and middle flange structure block valve after processing and assembling are shown in the figure.