Abstract: A cylindrical chamber (1) for an oscillating piston type of liquid counter comprises notably a biconcave fixed partition wall (9) and grooves on the lower and/or upper edges of the piston and, as the case may be, on the small cylinders of the chamber 1. The disclosure can be applied to the metering of liquid and, especially, to the metering of water.

Abstract: A device of the antifraud sealing cap type in the form of a unit having: a covering skirt (5) provided on the inside face of its upper edge with recesses extended downward by hooks (9) able to engage in shoulder (3) of threaded lock nut (2) provided on the body of the meter; a ring with an inside vertical lip (10) whose pin (11) projecting from the collar come to be inserted in said recesses (8); and a cover (12) whose opening and closing hinge (13) is pivoted in an opening made on the upper edge of the skirt. The device is particularly useful for antifraud covering of water meters.