Northwest Water Purification Plant Expansion Intake Pump Station

The project starts with (10) 72″ suction lines to feed the pumps on the platform that are not visible in this photograph. These pieces had to be floated into place under the platform using rubber balloons. The balloons were slowly deflated, and pipe was installed by divers underwater beneath the platform because this area was not accessible by an overhead crane. The raw water then leaves the discharge side of the pump cans into twin 96″ headers. A 72″ bypass line loops over the top of both lines so either one or both lines can be utilized at the same time.

The twin 96″ lines then angle toward each other to line up the twin 120″ pipe that will be used to launch pigs in the future to clean the lines. These lines then reduce down to the twin 109″ lines that runs across the bridge.

All the piping in the platform and the bridge had to be put on a barge and moved into place. The crane shown in the picture then lifted each piece into place for worked to install. There are 56 sliding and fixed supports on the bridge. The sliding supports have Teflon pads on the bottom and embedded plates in the concrete that will allow for thermal expansion and contraction. There are also 18 expansion couplings located on the 950 feet of pipe that runs the length of the bridge.

Once the pipe leaves the bridge, it then increases to twin 111″ OD pipe. This span of over 700 feet of pipe is buried before it ties into existing pipe.

The above ground piping is epoxy lined. The coating is a three-part system. The first coat is zinc primer followed by epoxy intermediate coat followed by an aliphatic final coat. The buried piping is cement mortar lined and polyurethane coated.