Abstract: A rotary valve having inner and outer sleeves includes multiple ports configured to provide pressure and vacuum pulses when the sleeves are rotated with respect to each other. A source of pressure and vacuum is connected to the rotary valve, and the inner sleeve is rotated to generate pressure and vacuum pulses. The alternating pressure and vacuum pulses may be used to remove obstructions in conduits such as piping systems. The rotary valve may also provide static positions where no vacuum or pressure is available. The valve may be motor driven and the pressure/vacuum pulse frequency may be controlled based upon the relative speed of rotation of the sleeves.

Abstract: A device for alternately applying pressure and vacuum to pipes in order to remove or prevent build-up of undesirable coatings inside the pipes is disclosed. The device includes a pressure and vacuum source connected to a plenum having a hose attached to the plenum at a proximal end and a control mechanism attached to the hose near a distal end. The control mechanism is operable to control the plenum to rapidly switch between variable amounts of vacuum and pressure to the hose. The plenum may also be controlled to supply neither vacuum nor pressure to the hose. The device may be used in a wide variety of settings, including industrial, commercial, marine hospitality industry, and household settings.