AWWA DSS71287

This powerpoint presentation begins by providing a brief overview of the difficulties in locating closed valves in a distribution system. Methods for finding closed valves include:get on the valve and operate;use hydraulic model to find closed valves; and,closed valves often found in calibration. Reasons why closed valves don't reveal themselves include:los velocity;change in head loss and pressure is negligible; and, aclosed valve shows itself during fires, shutdowns, and when you really need it open. Problems withboundary valves (BVs) include: 10% of existing BVs not sealed; and, 10% of proposed BVs won't seal. Problems of internal valves include: 12% of internal valves meant to be open are shut; and,if not addressed, can form new leakage management area; can accidentally cut supply to customers; make customer fire systems non-compliant; and,street hydrants operate at flows less than desired capacity. Includes tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2009

Number of Pages:

29

File Size:

1 file , 1.3 MB