machine tools and structural parts therefor for use in oil well installation, running, hanging, and cementing casing liners and sub-sea casings in a borehole, namely surge reduction diverter subs for use with downhole running tools to reduce the damaging effects of surge pressure on a borehole, wiper plugs for use with downhole running tools to facilitate cementing a casing liner or sub-sea casing in a borehole, valves and valve actuators for use with downhole running tools to facilitate runn...