A pressure and vacuum relief valve comprising a body having a central passage provided therein. A chamber is provided in the central passage to accommodate a baffle assembly provided to facilitate release of pressure from an enclosed mechanical environment to atmosphere and allow suction of air from the atmosphere into the enclosed mechanical environment. At least one baffle means is provided in the central passage below the chamber such that to act as barrier in the flow of oil vapours coming out from the enclosed mechanical environment. Threads are provided at lower end of the body to facilitate securing of the pressure and vacuum relief valve with the enclosed mechanical environment. A spring loaded cap being provided to cover top end of the body. In one embodiment a filter assembly is provided to cover the cap such that filter to filter the air sucked in and oil vapours coming out of the enclosed mechanical environment.
