A barrel lock for locking various utilities devices such as valves, meters, or enclosures associated with the control or distribution of gas, water or electricity includes a shank with a single driven ball that can be forced radially outward from the shank to lock onto a cap-like retainer such that the utilities device is restrained between the retainer and an enlarged head of the shank. The device includes a housing, an oil and gas inlet, a gas outlet, an oil outlet, a baffle, and a coalescing assembly to separate the oil from the oil and gas mixture. The server divides digital contents held therein into a plurality of packets, and transmits packets of a minimum unit for constructing the digital contents to the second network. The bitmask table and hierarchical log are used to determine when the LAs stored in the selected GCU are stale, and update the bitmask for each page in the selected GCU after the stale data has been erased. A final result for the corresponding software test of each intermediate result is generated from the intermediate result in response to the respective key not being present in the file cache. The scrubber includes a casing having an exhaust gas inlet and an exhaust gas outlet, an impeller housed in the casing and supported by a shaft, and a cleaning liquid supply tube for ejecting a cleaning liquid by which the dust contained in the exhaust gas is captured.