Abstract: A mechanical or acoustic excitation apparatus 26 imparts mechanical vibrations to a pipeline 12 in at least two longitudinally spaced areas of its outer surface. At least one sensor 30 is positioned in proximity to the pipeline, which collects vibration data supplied to it along the pipeline. A processing and analysis apparatus 40 derives from the vibration data information concerning the gas and liquid content of the multiphase fluid, in particular the length and rate of travel of liquid plugs and air pockets, and a control device 42 regulates intake valves of downstream petroleum equipment to adjust the intake flow rate of the phases as a function of the storage and/or treatment capacity of the equipment.

Abstract: A safety connection located between a vessel containing a gas under pressure and a gas discharge system comprises a pilot controlled valve which is provided with a separate control system for opening the valve, the valve having a ball-and-socket system between the actuating rod and the valve-closing flap which it carries, so that the valve can also function as a sluice so as to avoid the need to provide a second pipe connected to the vessel and provided with a sluice as is conventional.The actuating rod of the valve carries a piston, one face of which is normally subject to the pressure of fluid in the vessel via the pilot valve but is connected to a vent as soon as an overpressure occurs, to open the valve. The other face of the piston is normally connected to a vent but is subject to the pressure of a fluid from an independent source of control fluid when the separate control system is operated to open the valve.