Opening at a storage tank for gauging or sampling.
The Pressure/vacuum relief valve Pressure/vacuum relief valve is an umbrella term that includes pressure or vacuum relief valve as well as pressure and vacuum relief valve. gauging nozzle Gauging nozzle The gauging nozzle is part of the sampling device. is part of the sampling device Sampling device A sampling device allows for sampling from every filling level of the stored medium in a tank. . Closable gauging openings are opened for gauging and sampling.