Lock structure for ammonia nurse tank valve units

摘要

An anti-pilfer lock device is provided for protecting against unauthorized access to the flow control valve units projecting from the outer surface of a mobile ammonia nurse tank. A box-shaped housing is sized and configured to be removably mounted on the shell of the nurse tank in complemental conforming relationship thereto in a position shielding the flow control valve units to prevent theft of ammonia from the nurse tank. Lock structure is provided for releasably holding the housing in its valve protecting position on the nurse tank storage vessel. The lock structure includes a coupling bar connected to at least one of the control valve housings, and an extension strap secured to the bar extends upwardly therefrom through a slot in the top wall of the housing. A bolt cutter proof lock is removably connected to the upper end of the extension strap above the top surface of the housing. Upon unlocking of the lock and removal from the extension strap, the housing may be lifted from the tank to provide access to the flow control valve units. The lock structure may be left in place as the housing is removed and replaced from the tank.