Surveying and Valve Exercising
Having the ability to operate valves at a moment’s notice is extremely important. In an emergency, entire sections of a distribution system may need to be shut down immediately. However, if a valve is not used over a period of time it can seize-up from corrosion and/or silt, resulting in an inoperable valve.
Knowing the exact location of your valves has multiple benefits. Surveying and exercising valves gives you an accurate representation of existing water distribution assets, lets you know if water main valves are operating as they are designed to, minimize insurance and legal claims, shut down water pipelines quickly in case of a main break, lower the cost of damage to buried infrastructure, reduce the area of effect of a water main break, and have a management program for your water distribution system. An effective valve exercising program may help prevent damage to property, environment, and injury to the public and employees.
The American Water Works Association (AWWA) recommends that all water utilities initiate a valve exercise program that requires all valves to be inspected and operated on a regular basis. The objective of this page is to outline key elements of our comprehensive valve exercise programs in order to:
Help agencies determine the effectiveness of existing valve exercise programs
Improve the efficiency and productivity of distribution crews
Improve valve reliability
Reduce water loss
Identify critical valves on distribution system
Measure and document valve operation
Develop trend analysis
Develop or improve data used in a GIS system
After updating or developing your GIS, you will have detailed records of each valve. Viewing valves within your GIS allows maintenance crews to verify the valves they are operating are left in a specific state.
Each exercised valve has attributes within GIS including:
Valve type and size
Whether the valve is partially open
Notes on any anomalies
Maintaining a valve exercise survey program will allow water department personnel to have the resources they need in order to successfully maintain water valves and water lines.
Reduce revenue loss
System failure prediction would reduce water loss system degradation
Avoid costly liability and property losses
Create a manageable capital improvement budget
Enhance system reliability
Strengthen customer confidence
By regular surveying and valve exercising you will have the detailed records you need to ensure the operability of your distribution system. Surveying helps identify the condition and location of all your valves. Knowing the condition of your valves and having an updated GIS system helps eliminate; higher costs associated with water main breaks, lost time digging up buried valves, and congested traffic due to excavating roadways. When it comes to maintaining your valves, it’s better to be proactive than reactive!
American Water Works Association “Manual of Water Supply Practices – Distribution Valves: Selection, Installation, Field Testing, and Maintenance” (AWWA M44)
AWWA “Water Distribution System Assessment Workbook”
AWWA Operating Guide to G200 – “Distribution Systems Operation and Maintenance”