A good exercise program can be a real "turn-on." Other times it should be a real "turn-off," or so many water and wastewater utilities hope.
Valves are a critical part of any water distribution or treatment system because they alone regulate the flow of water, reduce pressure and prevent backflow. Much like the human body, they need to be exercised regularly to ensure that they operate properly when you need them the most.
Many systems fall into the habit of ignoring this important component of their distribution system—gambling with the safety of their customers—betting that the various valves that make up their systems will always work.
In this issue of the Safe Drinking Water Trust eBulletin we will tell you the best way to exercise your muscles (and your valves) to ensure that one of the most crucial pieces of the water-distribution puzzle is in top shape and ready to serve you when you need it.
Additional Resources
www.epa.gov/OGWDW/smallsys/pdfs/final_asset_inventory_for_small_systems.pdf [1]
Turning Over a New Leaf.
At the heart of every water distribution and treatment system is a vein-like series of interconnecting pipes and valves that control the flow of fluids. While the pipes create the path that the fluids follow, the valves serve as the mechanical means of starting, stopping and directing the flow.
Failure of a section of pipe is relatively easy to identify (just look for a pool of water). However, when valves fail the problem often goes unnoticed until the time comes when you need to stop the flow of water—usually for an emergency repair situation.
A good valve-exercise program should follow the notion that each and every valve in your distribution or treatment system should be tested (opened and closed) on a routine basis so that troublesome valves can be identified and necessary repairs made before you find yourself in a fix.
Most comprehensive valve-exercise programs can be broken down into four components and should be made an important part of your system's routine maintenance plan:
Knowing where each valve is located (location, location, location).
Fully exercising each valve ("doing the twist" as Chubby Checker liked to say).
Maintaining detailed valve records (the paperwork).
Scheduling and performing needed repairs (fix what needs fixing).
Additional Resources
http://ohioline.osu.edu/b910/b910_13.html [2]
No Pain—No Gain.
According to the American Water Works Association (AWWA), "Each valve should be operated through a full cycle and returned to its normal position on a schedule that is designed to prevent buildup of tuberculation (rust formation in pipes as a result of corrosion) or other deposits that could render the valve inoperable or prevent a tight shutoff."
For the sake of discussion, the hundreds of valves that make up your distribution or treatment system can be compared to a skydiver's parachute. Even the most inexperienced plane-jumper isn't likely to leap out of a perfectly good airplane without being absolutely certain that the parachute is going to work flawlessly. Like a valve, the parachute is often the one safety mechanism standing between a thrilling adventure and….big problems!
Experiencing valve failure, or a parachute failure, is definitely a mistake that most people won't want to encounter more than once in a lifetime.
This simple truth should be applied to the mechanical valves in your system: Valves are generally the one safety feature that has the ability to stop the flow of water through your system and it is essential to the safety of your customers that they work flawlessly each and every time they are needed.
Additional Resources
www.scdhec.gov/eqc/water/pubs/swpref.pdf [3]
Oh Where Oh Where Can My Little Valve Be?
One of the most difficult concepts for most utilities is getting past the notion that a valve exercise program must be some type of colossal undertaking, therefore making it nearly impossible to accomplish.
This just isn't the case. In fact, a valve-exercise program should already be an important part of every water system's Sanitary Survey.
Tip: A sanitary survey is an onsite review of your water source, your facilities, equipment, operation and maintenance that makes up your water-treatment system. These reviews by trained water professionals are to be conducted every three years by community water systems and every five years by noncommunity water systems.
In reality, a modest beginning can achieve nearly instant positive results, creating a safer environment for your employees and your customers and saving your system money.
The first step in implementing a valve-exercise program is to create a plan that covers the complete process from how often your valves will be given a thorough workout to who will be responsible for the process. Don't forget that hydrants are a specialized form of valve and also need to be exercised and flushed on a scheduled basis.
Spend a little time with your staff working through this process so that you best utilize their valuable time by prioritizing this with other maintenance tasks.
Once you have determined how often and who will be responsible for exercising your valves, the next step is to determine the number and type of valves that are included in your system and placing this information on a simple map.
Not sure how to begin mapping your water system? Just check out our Ask-An-Expert resource found along the left side of the screen for assistance in your area. Or click here to request further assistance: Ask-An-Expert.
Additional Resources
www.cdphe.state.co.us/wq/Drinking_Water/pdf/SystemsofConcern/ColoradoPWSSelf-Evaluation.pdf [4]
One Good Turn Deserves Another.
Once the valves in your system have been located, it's time to begin cranking. Most water experts suggest that you create a valve operation worksheet to keep for your records. This worksheet will allow you to record the date and location of each valve as it is exercised, the number of and direction of turns each valve requires and any problems or deficiencies that are encountered.
Tip: Be sure to check out this month's Management-at-a-Glance section for a sample valve operation worksheet.
In order to provide a complete workout, it is recommended that each valve be fully opened then fully closed before it is returned to its proper setting. This will allow for the flushing of debris.
It is always best when exercising valves to remember not to force the valve open, or closed, too quickly to avoid creating a water-hammer effect.
Water hammer (or hydraulic shock) is a sudden surge of pressure that can be created when the flow of fluids is stopped or the direction of flow is changed too quickly.
The resulting shockwave, or fluctuation in pressure, has been known to damage or rupture water mains.
According to many industry experts, most valves have a life expectancy of roughly 30 years and should be exercised at least once a year.
Additional Resources
www.nesc.wvu.edu/ndwc/pdf/OT/TB/OT_TB_Su02.pdf [5]
Fixing What You Find.
Once all broken valves have been identified, it is important to determine which valves are most critical so that work orders can be issued.
Every water utility must give serious consideration to proper valve maintenance to assure the future reliability of the system. It is also important when evaluating the security of your system that you have the ability to open and close valves so that you could potentially isolate portions of your distribution system if the need should arise.
Many would argue that a proactive valve-exercise program is the one thing that any water utility can undertake that will have the greatest number of positive results for both the utility and its customers.
Nearly every water system has a horror story that could have been averted if a proper valve-exercise program had been followed. In many cases these troubles resulted in costs that far exceeded the price of implementing a valve-maintenance program.
Turning Your System "On" to a Valve-Exercise Program.
As with any good exercise program, the hardest part is often knowing what to do and then motivating yourself to get started.
However, once you get moving, the benefits will far outweigh the initial pain that you felt when you first started.
And remember, your valve-exercise program can also be a valve-locate program and a valve-box cleanout program—kind of like a cross-training and a weightlifting program all rolled up into one.