What is the method of reaming the valve seat?

Generally, the valve seat should be roughly hinged first and then finely hinged. The specific methods are as follows: before repairing the valve seat, check the valve guide. If it does not meet the requirements, replace or repair the valve guide first to ensure that the valve seat coincides with the center line of the valve guide; According to the diameter of the valve head and the angle of each conical surface of the valve seat, choose a set of suitable valve seat reamer. According to the inner diameter of the valve guide, select the appropriate valve reamer rod, and the reamer rod should rotate flexibly without looseness when inserted into the valve guide; After the valve seat is hinged, a little abrasive should be applied between the valve and the valve seat for grinding to ensure the seal between the valve and the valve seat; Finally, check the tightness between the valve and the valve seat, and check it by marking. Draw a vertical line on the valve sealing cone every 10mm with a soft pencil above 2B, put the valve into the valve guide, press the valve and valve seat by hand and turn it back and forth for 1/4 turns, then remove the valve for inspection. If all the scribing lines are cut off, the valve and valve seat are well sealed.