Abstract: An assembly for selectively locking the operating handle of an electrical switch in either the ON or OFF position which includes a blocking member having a first portion for engaging a housing through which the switch handle projects, and a second portion defining a recess or opening for receiving therein the switch handle. A fastener extends through the blocking member and into the second portion recess for selective locking engagement with the switch handle. The blocking member also includes a grooved portion for receiving a slide which may be locked in position to cover and prevent access to the fastener.

Abstract: An improved cleaning system for removing residue from the inside walls of a tank by directing a cleaning solvent flow completely over the tank inner walls at a controlled, minimum pressure. The cleaning solvent is directed through a ring assembly, which equalizes the flow of cleaning fluid through a series of equally spaced openings around the outer periphery of the ring assembly, and is supported such that the openings direct the fluid onto the uppermost surfaces of the tank interior wall. The ring assembly includes a series of releasably secured components and a valve for regulating the fluid flow rate through the openings.