Abstract: A safety device for venting excess pressure in a wet capacitor container (1) includes a lift valve (4) disposed in the wall or lid of the container, the body of the valve (4) being disposed with the aid of at least one resilient member (6) for being pressed against the valve seat (7) against the action of the pressure prevailing in the container (1), the member (6) being implemented as a resilient tongue (6) on a washer-like spring (8), where the tongue has been bent over in a direction towards the valve body (5). The spring (8) is also provided with a plurality of tongues (9) bent over in a direction away from the valve body (5) for retaining the spring (8) in the container.