Abstract: A pulsating vibration air generation apparatus capable of sharply and quickly controlling air flow in turning on and off operation, thereby generating a pulsating vibration air with sharp and hardly attenuated peak and valley, and capable of operation without occurrence of so much mechanical vibration. The pulsating vibration air generation apparatus is comprised of a main body having a tubular hollow space R2 with which two air communication ports are associated, and a rotary body situated for rotation in the tubular hollow space R2 and which has a peripheral side surface S4c so as to slide on the inner surface S2c forming the tubular hollow space R2.

Abstract: A device and method for venting a tank comprising an intermediate shutoff valve as part of a cover that closes a tank opening. The intermediate shutoff valve is placed between an existing valve and a vent port in a liquid storage tank. The shutoff valve is operable to substantially fluidly seal the vent port when the vent valve is displaced greater than a predetermined amount. The intermediate shutoff valve facilitates complete removal of the existing vent valve during an impact wherein a wall of the storage tank impacts the existing valve. Upon impact, the intermediate shutoff valve is operable to close and seal a tank opening created by the displacement and removal of the existing vent valve.