Load controlling bolted flange deformable spacers

A spacer assembly for absorbing energy for a flange bolt, the spacer assembly comprising:

• an inner body having a first inner body end, a second inner body end, an inner body outer surface having an inner body outer diameter, an inner body inner surface having an inner body inner diameter and an inner body longitudinal axis, and an annular chamfer at an inner body transition from the inner body outer surface to a first inner body end surface;
• an outer body having a first outer body end, a second outer body end, an outer body outer surface having an outer body outer diameter, an outer body inner surface having an outer body inner diameter that is greater than the inner body outer diameter so that the inner body and the outer body are substantially concentric when the first inner body end is inserted into the first outer body end;
• and
• an annular shoulder extending from one of the inner body and the outer body so that the other of the inner body and the outer body makes contact with the annular shoulder when the first inner body end is inserted into the first outer body end to prevent the inner body from passing through the outer body, the annular shoulder having an annular rounded transition surface at a point that a first shoulder engagement surface extends from one of the inner body and the outer body, wherein the first shoulder engagement surface is engaged by the first inner body end surface or the first outer body end, and wherein the annular shoulder is configured to fail in shear when a compressive axial load forcing the inner body and the outer body toward each other exceeds a predetermined shear failure load.