Description

Frequently, hold down measures are specified to prevent cathodically protected steel underground storage tanks from “floating out” due to high water tables or floods.  These hold down measures normally include the installation of a reinforced concrete pad or precast reinforced concrete “deadman” anchors below the tank.  The tank is then anchored to this concrete ballast using steel straps with the capability of tensioning the straps using a threaded connection or turnbuckle.  When the straps are attached to the pad connections, continuity is made between the straps and the reinforcing steel in the concrete ballast.  This creates an undesirable additional, and generally unknown, demand on the cathodic protection system for the tank.  Therefore, the hold down straps must be isolated from the tank to ensure the proper operation of the tank’s cathodic protection system.  If the hold-down straps are constructed of a non-metalic
material, isolation material is not required.

Table of Contents; Introduction, Isolation material specificatrion, Isolation material installation. See also R011Recommend Practice for Anchoring of Steel Undergound Storage Tanks