GOC372606-CS - Double Block and Bleed for the Main Chilled Water Supply and Return Lines

A double block and bleed system consists of 2 valve with a spacer in between for a drain to be install on the bottom of the pipe. During a system shut down the 2 large valves are closed and the drain is open to provide an indication that the valves are holding back the fluid while work is being performed downstream of the valves. The Cliff Street chilled water 16" dia. supply and 16"dia. return lines do not have this system. The CD Howe building has to rely and a single valve in the Cliff Street Heating Plant tunnel for the isolation.