Valve assembly for controlling the intake and delivery of a working fluid to be compressed in a compression unit, said valve assembly comprising: a plate provided with at least one intake opening, passing through said plate, and at least one delivery opening, passing through said plate, at least one laminar elastic intake valve, inferiorly associated to said plate, overlying said at least one intake opening, to close the same, capable of taking a deformed configuration, away from said plate, in which it delimits at least one passage opening for said working fluid to be compressed, at least one laminar elastic delivery valve, superiorly associated to said plate, overlying said at least one delivery opening, to close the same, capable of taking a deformed configuration, away from said plate, in which it delimits at least one passage opening for said compressed working fluid, said at least one laminar elastic intake valve and said at least one laminar elastic delivery valve being circular, connecting means adapted to constrain said laminar elastic intake valve and said laminar elastic delivery valve to said plate, said valve assembly comprising an abutment element, substantially disc-shaped, superiorly in abutment against at least one central portion of said at least one laminar delivery valve, and associated with said laminar delivery valve through said connecting means, characterized in that said abutment element is adapted to limit and control the elastic deformation of a remaining peripheral portion of said at least one laminar elastic delivery valve, guiding it through a curvilinear side surface, wherein said abutment element has an upper surface and a lower surface, substantially flat, mutually joined by said curvilinear side surface wherein said side surface is radiused to said lower surface. a plate provided with at least one intake opening, passing through said plate, and at least one delivery opening, passing through said plate, at least one laminar elastic intake valve, inferiorly associated to said plate, overlying said at least one intake opening, to close the same, capable of taking a deformed configuration, away from said plate, in which it delimits at least one passage opening for said working fluid to be compressed, at least one laminar elastic delivery valve, superiorly associated to said plate, overlying said at least one delivery opening, to close the same, capable of taking a deformed configuration, away from said plate, in which it delimits at least one passage opening for said compressed working fluid, said at least one laminar elastic intake valve and said at least one laminar elastic delivery valve being circular, connecting means adapted to constrain said laminar elastic intake valve and said laminar elastic delivery valve to said plate, said valve assembly comprising an abutment element, substantially disc-shaped, superiorly in abutment against at least one central portion of said at least one laminar delivery valve, and associated with said laminar delivery valve through said connecting means, characterized in that said abutment element is adapted to limit and control the elastic deformation of a remaining peripheral portion of said at least one laminar elastic delivery valve, guiding it through a curvilinear side surface, wherein said abutment element has an upper surface and a lower surface, substantially flat, mutually joined by said curvilinear side surface wherein said side surface is radiused to said lower surface.