As the popularity of no-drain winterizing grows, it’s no surprise that there are new plugs to facilitate this process on the market. To help you understand how to evaluate these options, we set up a simulated pool plumbing system and tested the Duck Plug against our primary competitor’s blow-through plug. The tests were designed to imitate three key elements of the blow-out process and each test was performed using the Big Blue Blower. Check out our findings!
Water Purge Rate
At the initial stages of the line purging process 2-5 lbs of pressure is required to push water from the lines. During this phase Duck Plugs purge lines more than twice as fast as competitor’s plugs because the duck billed valve opens to a much larger unobstructed aperture. The competitor’s plug does not even open at lower pressures. This is especially a problem if using a lower performing blower and/or when some lines start blowing air and back pressure is reduced for the remaining filled lines.
Because Duck Plugs open to a larger aperture, and do so at lower pressures, they also allow substantially more air flow as lines begin blowing air. Air flow is important to clear all water from lines even in low spots. As more lines begin blowing air, the flow rate increases at the main line (trunk) but decreases at each spur (branch). To increase flow at spur lines, Duck Plug valves can be easily blocked with simple paper clasps whereas competitor plugs have no way of being blocked.
The lower flow rate of the competitor’s plug creates a higher back pressure during the clearing stages of the process for a longer period of time. The blower therefore labors harder and longer to clear lines. This will cause the blower to heat up faster and wear out sooner.
A final important difference was noted consistently during testing. The competitor’s plug slowly leaked water back into the purged line after the blower was turned off. This resulted from the conical seal being pulled back into the funnel shaped opening at a slight angle. Duck Plugs, on the other hand, have been tested in thousands of pools over the toughest of winters without any known case of valve failure.
Want to see the Duck Plug in action? Check out this video to see for yourself how Duck Plugs and the Big Blue Blower work together to clear plumbing lines quickly and effectively.
What happens underground in the winterizing process? By setting up a clear PVC pipe system we can visualize the process and some of the challenges to winterizing pipes. This demonstration shows us that effectively utilizing the proper equipment and technique for blowing out plumbing lines is crucial for consistent, successful winterization. It is important to understand the three main phases of the process:
Water purge phase
Line clear phase
In the water purge phase, the water that fills the lines is “pushed” out of the pipe and replaced with air. Several factors are important to accomplish this part of the process effectively. First of all, the air source you use must provide enough air pressure to counter the back pressure of the water in the pool. When blowing out return lines this is a pretty low threshold, however when purging water from the main drain line a minimum of 4 psi of pressure must be achieved to push against the 8 feet of water in many deep ends. The second important factor during the purge phase is the amount of water flow that can be pushed through your blow-out plugs. The wider these plugs open under the appropriate pressure the more water you will be able to clear from the line at a fast rate.
The line clearing phase happens after most of the water has been purged from the lines but may still remain in low parts of the plumbing. Your ability to generate a high air flow rate through the purged lines is the critical factor in successfully blowing this remaining water from these locations. Choose an air source that delivers at least 100 cubic feet per minute (cfm) of air flow – most compressors only produce 2-5 cfm so you will need a blower. And again, use blow-out plugs that open wide at low back pressure to assure that the blower’s power can be realized as flow through the pipes. On return lines with more than one return branching off the main line, strong air flow to the farthest branch can be achieved by blocking the flow of cleared branches earlier in the run.
Once the lines have been cleared of water they must remain so over the course of the winter, so the plugs must effectively seal to prevent water from re-entering the plumbing from the pool. It’s still a good idea to pour antifreeze into the cleared lines just in case undiscovered cracked fittings, damaged threads, or badly installed plugs allow some water back in. After pouring antifreeze into the cleared line, turn the blower back on just long enough to see it blown into the pool through your blow-out plugs. The remaining anti-freeze will settle into low spots in the plumbing . . . just the spots that would be prone to problems if water got in.
Anderson’s Big Blue Blower and Winter Duck Plugs deliver the performance you need to assure each phase of the blow-out process is done effectively. The blower produces enough pressure “umph” to blow-out even the deepest main drain and provides an exceptional amount of air flow to clear all low spots in plumbing. Winter Duck Plugs open wide at low back pressures to clear lines quickly during the water purge phase and enable high air flow during the line clearing phase. Additionally, they can be easily blocked during this clearing phase with simple office binder clips to facilitate flow to all branches of the return system. Most importantly, over the past 10+ years, Winter Duck Plugs have proven themselves dependable at keeping water out of lines and protecting thousands of pools from winter freeze damage.
For a comparison of how Winter Duck Plugs compare to other blow-out plugs on the market see the results of our testing here.