A gravity-operated anti-surge valve for a turbine pump consists of a poppet adapted to be moveable under fluid pressure between a closed position and a valve seat for the poppet. The weight of the poppet biases the poppet in the closed position against the valve seat in the absence of fluid pressure. Fluid pressure developed by the pump forces the poppet open. As fluid pressure decreases when the pump is shut off, the weight of the poppet allows the poppet to gradually close against continuing fluid flow, preventing water hammer. As fluid pressure approaches zero, the poppet completely closes, preventing the weight of a column of water from rushing down the lineshaft at high speed and driving the pump impellers in reverse. The valve is located above the top bowl of the pump.
A submersible pump assembly has a pump and a valve connected to the outlet of the pump. An outlet of the valve is connected to a riser. A valve member in the valve housing is vertically movable between a pumping position and a priming position, the valve member being biased toward the priming position. A priming conduit connects the outlet of the valve housing to the inlet of the pump for directing well fluids flowing through the conduit into an intake of the pump for re-priming the pump. When the pump is pumping well fluid, the valve member is moved to the pumping position by the fluid pressure, well fluids flowing from the inlet of the valve housing to the outlet of the valve housing but not through the priming conduit. When pumping ceases, the valve member returns to the priming position, well fluids flowing through the priming conduit for re-priming the pump.
