Methods and apparatus to couple valve shafts and closure members

A method of coupling a closure member and a valve shaft, the method comprising:

• inserting a first tapered pin in a first opening adjacent a first end of an expansion pin such that a first portion of the expansion pin adjacent the first end does not expand;
• disposing the expansion pin and the first tapered pin in a receiving bore of a closure member and a valve shaft, wherein the first tapered pin engages a surface of the receiving bore adjacent a face of the closure member;
• driving the expansion pin toward the first tapered pin to cause the first portion adjacent the first end of the expansion pin to expand against an inner surface of the receiving bore at a first location;
• and
• disposing a second tapered pin in a second opening adjacent a second end of the expansion pin to cause a second portion adjacent a second end of the expansion pin to expand against the inner surface of the receiving bore at a second location different from the first location.

A coupling apparatus for use with fluid valves, comprising:

• means for coupling a valve shaft and a closure member, wherein the means for coupling comprises:
• first means for causing an expansion pin disposed within a bore of the valve shaft and the closure member to expand at a first location of the bore;
• and
• second means for causing the expansion pin to expand at a second location of the bore that is different than the first location of the bore.