Novelty Hill Butterfly Valve Replacement

Vicinity Map

Location: Several locations, see vicinity map

Project Phase: Construction

Estimated Timeline: Construction will begin in September 2018 with completion in May 2019.

Contact: Eric Dawson, 425-556-2867

Page Last Updated: 09/25/18

Description:
At the Novelty Hill Pump Station and the Novelty Hill Operations Center Tank site, City maintenance staff discovered a consistent valve isolation problem that has degraded over time. The City maintains approximately 65 butterfly valves to isolate sections of the piping within the facilities. These valves range in size from 8 to 24 inches and have degraded to a point where they no longer close properly, making it very difficult for the staff to isolate parts of these facilities to perform routine maintenance.

During the initial investigation of the problem staff employed a corrosion expert to evaluate the condition of the valves and pipe in both facilities. The results of this evaluation revealed consistent corrosion of the pipe spools as well as failure of the valve seats in both facilities.

This project will replace 65 butterfly valves and a majority of the corroded pipe spools. When completed, City maintenance staff will be able to isolate parts of the Novelty Hill Facilities to perform maintenance. As part of the project, a seismic control valve operator will be also installed at the tank sites to isolate the tank water supply in the event of a significant seismic event.