between the housing and a swirl array including a swirl chamber provided with a dispensing port as well as at least one supply duct for the chamber the swirl chamber being defined by a side surface having a frusto conical shape relative to which the supply duct extend in a transverse plane the side surface tapering from an upstream end into which the downstream end of the supply duct tangentially extends to a downstream supply opening of the dispensing port the dispensing port having an outlet size that is equal to the internal size of the downstream opening application_number US 201213464303 A description in relation with the figures a push button for a dispensing system for a product in particular liquid under pressure is described hereinbelow said product able to be of any nature in particular used in perfumery in cosmetics or for pharmaceutical treatments the push button comprises a body 1 having an annular skirt 2 which surrounds a well 3 for the mounting of the push button on a feed tube 4 of the product under pressure moreover the push button comprises an upper zone 5 allowing the user to exert a finger press on said push button in order to be able to displace it axially in the embodiment shown the push button is provided with a trim 6 for aspect that surrounds the body 1 and whereon is formed the upper zone 5 for pressing in relation with fig1 the dispensing system comprises a system for sampling 6 provided with a feed tube 4 of the product under pressure which is inserted in a sealed.