System for sealing the nozzle of a steam generator

摘要

A system for sealing the nozzle of a steam generator including a collapsible nozzle dam and an installation pivot arm. The collapsible nozzle dam includes a base portion receivable through a manway in the steam generator for retaining an inflatable seal in place within the nozzle, a post extending from the base portion, a plurality of foot assemblies positioned radially about the post for engaging a nozzle ring around the nozzle of the steam generator, a truss structure for supporting the foot assemblies with respect to said base portion including compression legs interconnecting the foot assemblies with the base portion and tension legs interconnecting the foot assemblies with the post. The foot assemblies fold about the post for insertion thereof through the manway to unfold once inside the steam generator for engaging the nozzle ring and positioning the base portion within the nozzle. The installation pivot arm transports the collapsible nozzle dam from the manway to the nozzle and includes a support having a proximal end securable to the manway of the steam generator and a distal end securable to the nozzle ring, a nozzle dam attachment and positioning backing plate, and a four bar linkage.