There are a lot of exciting features to be seen at the Chimney Hollow construction site. However, some of the most critical components of the project are hidden from the eye. Upon completion, there will be 61 valves installed, including four 72-inch diameter butterfly valves to provide isolation between the inflows to Chimney Hollow and the Colorado-Big Thompson Project. The first of these valves is currently enroute to the site from Germany where they are manufactured. The first butterfly valve will be installed inside a valve vault located adjacent to the wye connection in the Bald Mountain Tunnel. As the name suggests, the wye is a Y-shaped connection used to join two pipes together, usually at a 45-degree angle. The valve is also essential in the event of an emergency where a closure can prevent damage to the downstream valve house.

Vishal Gajera, Mechanical Engineer for Stantec Engineering, recently traveled to Germany for the factory acceptance testing of the Bald Mountain Interconnection butterfly valve. Test procedures include dye penetrant tests of the valve shell and disc to check for any leakage, hydrostatic pressure tests at one-and-a-half times the design pressure and functional tests to ensure proper valve operation. As part of the functionality testing, the valve was also tested for excessive vibration, sound and how smoothly it opens and closes. No leaking, distress or signs of abnormality were observed.