A system for dampening the vibrations experienced by a sensing line connected to a jet pump within a nuclear reactor pressure vessel. The system may include an eccentric clamp assembly (ECA). The ECA includes: a cam member and saddle; a key member, such as a t-bolt; an eccentric member; a clamp member; clamp body. A jacking bolt, washers, and an ECA connector lock the assembly in place. The ECA allows for adjustment in multiple directions, reducing installation time.