After the new conduit of the generator set is loaded into the cylinder head, the reamer is applied to correct the conduit's circularity and inner hole size, so that the clearance between the valve rod and the conduit hole conforms to the provisions of the generator set's specification, and the valve rod that has been refined cannot be processed. In use, the clearance between the valve rod and the conduit hole shall not exceed the wear limit specified in the unit specification. Generally, as long as the clearance between the valve rod and the conduit reaches 0.13mm (the diameter of the valve is equal to or less than φ8mm) or 0.16mm (the diameter of the valve is greater than φ8mm), it is necessary to replace the valve or the conduit, otherwise it will lead to early damage of the valve.
