A sounding valve is a self-closing valve for manual sounding of a tank. It is equipped with a ventilating valve to release any possible pressure in the tank, which is a safety measure before sounding. The sounding valve is normally mounted on an extension from the tank top. A sounding tube is normally built into the deck for sounding of various tanks and media. The body material is steel and it can be delivered in various dimensions to fit different pipe sizes. The cap of both sounding valve and sounding tube is equipped with a chain and has a sealing gasket to prevent leakage. The sounding valve can be delivered with a foot pedal. When mounted on the tank top a foot pedal can facilitate and ease the handling depending on the placement of the sounding valve.