Three-way valve for an attenuator

Abstract From the Canadian patent

A three-way valve for use in a fluid pulsation attenuator having a flexible diaphragm forming an interface with a flow of pulsating fluid on one side and a chamber of pressurized air on the other. The valve includes a head and an attached sliding tube having a plurality of orifices through its wall. As the head follows movement of the diaphragm the, sliding tube moves between positions which permit one or more orifices to communicate with chambers in the valve to either introduce additional pressurized air into the air chamber portion of the attenuator or to, discharge air therefrom, as needed to quickly achieve, matching, at start-up and the continuance of matching, of the air chamber …