Nozzle dam segment bolt and keeper

In a nuclear steam generator isolation dam segment assembly, a bolt assembly and a keeper member combination for securing a plurality of assembled dam segments,

• said bolt assembly including an elongated bolt body having an outer dam segment engaging surface portion, an axial bore in said bolt body, a first and large diameter bore portion at one end of said bore, a second and reduced diameter bore portion at the opposite end of said bolt body bore, an elongated bolt pin slidably mounted in said bore and including a first and large diameter pin portion in slidable engagement with said first and large diameter bore portion and a second and reduced diameter portion at the opposite end of said pin in slidable engagement with said second and reduced diameter bore portion first means for biasing said bolt pin and said first and large diameter pin portion axially toward a position of projection from the end of said first bolt body bore portion, and, means for rotating and securing said bolt pin and said first and large diameter pin portion in both a position of retraction within said first and large diameter bolt bore portion against said means biasing said pin and in a position of protection from said first bolt body bore portion;
• said keeper member including an elongated keeper body having a dam segment engaging surface portion, an axial bore in said keeper body for receiving said bolt pin when said keeper member is mounted on one dam segment opposite said bolt assembly on an adjacent dam segment assembled thereto,
• said bolt pin having a transverse projection adjacent the end of the large diameter pin portion remote from said small diameter pin portion,
• said keeper body axial bore being in open communication with a slot parallel to said bore for receiving said transverse projection as said bolt pin is projected and received in said keeper body axial bore, said keeper body and said bolt pin being proportioned to permit said transverse projection to pass to the end of said slot and be rotated into engagement with the end of said keeper body opposite said bolt pin assembly, and,
• second means for biasing acting to urge said rotated bolt pin transverse projection toward said end of said keeper body against the force of the means biasing the large diameter pin portion axially toward a position of projection from the end of said bolt body.