US Patent 8939217 Hydraulic pulse valve with improved pulse control

Hydraulic pulses are produced each time that a pulse valve interrupts the flow of a pressurized fluid through a conduit. The pulse valve includes an elongate housing having an inlet configured to couple to the conduit to receive the pressurized fluid, and an outlet configured to couple to one or more tools. In the housing, a valve assembly includes a poppet reciprocating between open and closed positions, and a poppet seat, in which the poppet closes to at least partially block the flow of pressurized fluid through the valve. A pilot within the poppet moves between disparate positions to modify fluid paths within the valve. When the valve is open, a relatively lower pressure is produced by a Venturi effect as the fluid flows through a throat in the poppet seat, to provide a differential pressure used to move the pilot and poppet. An optional bypass reduces the pulse amplitude.