Check valve for a fluid comprising: - a hollow body, configured externally to sealingly insert itself in a fluid duct and extending around a body axis so as to delimit internally a body cavity for crossing of said fluid; said body comprising an annular abutment bead projecting radially into said cavity; - a mobile obturator, housed at least partially in the body cavity and subject to being reversibly moved by the fluid transit between an interception configuration, wherein said obturator sealingly lies on the annular abutment bead, and a transit configuration of said fluid, wherein the mobile obturator is distanced from the bead; wherein the hollow body and the annular abutment bead are joined to each other without fluidic sealing elements; - elastic means acting between the hollow body and the mobile obturator to continuously move the latter towards the interception configuration, in opposition to the force exercised by the fluid flow transiting in a predefined direction through said body; wherein an axial end of the body cavity is partially delimited by a closure element, connected to said body in a releasable manner, and wherein the elastic means act on an inner annular wall of said element, from which a plurality of spokes extend, delimiting between them apertures for the transit of said fluid; - at least one compression limiter of the elastic means in the transit configuration, which acts on a lower surface of the mobile obturator to prevent excessive compression of such means, said compression limiter being arranged at the closure element; wherein the lower surface of the mobile obturator is arranged on the bottom of a spring seat, which is formed in the mobile obturator said check valve being characterized in that the spring seat houses the elastic means completely when the mobile obturator abuts the at least one compression limiter in the transit configuration. - a hollow body, configured externally to sealingly insert itself in a fluid duct and extending around a body axis so as to delimit internally a body cavity for crossing of said fluid; said body comprising an annular abutment bead projecting radially into said cavity; - a mobile obturator, housed at least partially in the body cavity and subject to being reversibly moved by the fluid transit between an interception configuration, wherein said obturator sealingly lies on the annular abutment bead, and a transit configuration of said fluid, wherein the mobile obturator is distanced from the bead; wherein the hollow body and the annular abutment bead are joined to each other without fluidic sealing elements; - elastic means acting between the hollow body and the mobile obturator to continuously move the latter towards the interception configuration, in opposition to the force exercised by the fluid flow transiting in a predefined direction through said body; wherein an axial end of the body cavity is partially delimited by a closure element, connected to said body in a releasable manner, and wherein the elastic means act on an inner annular wall of said element, from which a plurality of spokes extend, delimiting between them apertures for the transit of said fluid; - at least one compression limiter of the elastic means in the transit configuration, which acts on a lower surface of the mobile obturator to prevent excessive compression of such means, said compression limiter being arranged at the closure element;