A pipe fitting and associated piping joint assembly package allow re-use and repair of push-fit piping fittings and valves without damage to the fitting or valve elements or the pipe, and without coining, gluing or threaded engagement of parts. The hydrodynamic bearing device includes a shaft relatively rotatably inserted into a bearing hole of a sleeve, a radial bearing surface having dynamic pressure generating grooves formed on at least one of an outer peripheral surface of the shaft and an inner peripheral surface of the sleeve, and a gap filled with a working fluid between the shaft and the sleeve. An apparatus comprising an iridium-containing layer is also presented. In another embodiment, the three signals are obtained from a column buffer having only one output. The client device may send, to the worker device, information associated with performing the task, and may receive, from the worker device, an indication that the task has been performed.