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, a
closed valve shows itself during fires, shutdowns, and when you really need it open. Problems with
boundary 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.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.3 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 29 |
| Published : | 11/01/2009 |
