Bladder Surge Tanks Cured Excessive Surge Conditions in a 30” Force Main
Authors:
- Bo Copeland, P.E., and Sean FitzGerald, P.E, - Hazen and Sawyer
The Lakeview Pump Station (PS) in Fort Wright, Kentucky, which was constructed in the mid 1970s, is a wet well-dry well PS with 8 centrifugal pumps (4 parallel sets of 2 pumps in series) with a combined pumping capacity of 21 mgd. The Lakeview force main (FM), which is primarily 30-inch-diameter prestressed concrete cylinder pipe (PCCP), is over 3 miles long. The system operates at pressures over 200 psi and was experiencing transient pressures (surge) up to 500 psi.
Full vacuum conditions and subsequent vapor cavity collapse were also occurring in the higher portions of the FM during surge events, which had routinely generated vibrations and noise at nearby homes resulting in customer complaints. In June 2009, a power outage at the PS created surge conditions that split a 14” gate valve in the PS, flooded the dry well and submerged the pumps and motors.
