As many of you know, I am often hailed as the “no main drain guy,” because for the last 6 years I have been pushing for the option (not the mandate) to build pools without a drain. You can read more about this concept in the November 2008 WaterShapes Magazine
. If you want the full technical scoop, you can download it here.
I still believe that many pool drains can be eliminated and completely remove the hazards of suction entrapment.
For now, I want to talk to you about pools that HAVE drains or existing covers you may have to replace due to the Virginia Graeme Baker Pool and Spa Safety Act
. Our industry is under mandate to replace all public pool drain covers by December 19, 2008 or the first day the pool is open after the next season. These new covers must be tested to an updated National Standard: ASME:A112.19.8(2007)
. This standard was a significant upgrade in safety from the previous cover standard. It added three very important testing components: Full Head of Hair, Body Block, and Material UV
These tests are all designed to make sure that the cover is not only safe, but that it will remain in tact. Most accidents happened because covers become broken or missing for a plurality of reasons. The U.S. Consumer Products Safety Commission is the enforcer of this particular congressional act and has come up with a standard label to place on all of these cover “VGB 2008” by designation of this letter
On the residential side, the CPSC will disallow the sale of covers that do not meet the the new standard. This will slowly eliminate these covers on existing pools. While there is no mandate to replace the existing covers in residential pools, it is a good idea for safety to do it - whether required by law or not. It's the right thing to do. There will be more information on the legal aspects of this and your responsibility offered by our Pool Genius Adviser Stephen Getzoff
in the weeks to come.
Here is one thing that likely no one has told you and it will be VERY
important as we replace covers on existing pools. “Suction Outlets” as are being tested in the above ASME standard are defined to include: cover, attaching screws, and the sump.
In other words, simply having a cover that’s stamped with “VGB 2008” is not enough - the manufacturer must have specifically tested and specified that this cover is intended to work with your manufactured or field manufactured sump. As well, the screws are the weak link - remember broken or missing covers up above? If you replace an old cover with a new cover, but in the process strip the screws, you have decreased safety, while appearing that you are technically complying. It is imperative to be certain that NO SCREWS are stripped, the cover is SECURELY in place, and the flow rate does not EXCEED that which is printed on the label.
Equally important for field fabricated sumps, you should remember that in the absence of a manufacturers specification, you will need 1.5 x diameter of the pipe underneath, at the center (where the pipe comes through the shell) and 1 diameter at the edge of the grate. We don’t typically plaster in grates with this sort of clearance, but no one is talking about it. Here is a diagram from the ASME standard on field fabricated sumps:
Figure 2 from ASME A112.19.8(2007) ©2007 ASME all rights reserved.
Take a look at this public spa I recently visited. It has at least 4" (maybe 6"?) piping and that appears to be a 12 x 12 flat (it perhaps is a 9 x 9 hard to tell and I did not measure it - if you can identify the cover please add a comment) In any event - exactly what needs to be replaced. Now look at the clearance between the drain cover and the sump - 3.4 inches? I certainly does not meet the 1.5 diameter called out in the standard. So a cover for this sort of installation would either need to be rated for this shallow clearance or the sump must be modified to meet requirements in the table above.
Example Spa Cover with Field Fabricated Sump - This is a tough call on what cover to use
Finally and most important is to measure the flow rate on your system. This is primarily to ensure hair entanglement protection. Each of the dual outlets must be rated with a number ABOVE the maximum system can flow. If the covers are rated at 125 GPM, and there are 2 drains, you CANNOT
flow 250 GPM through the outlets. For dual outlet installs, the maximum flow through the pair is the lowest number printed on the cover. Flow rate can be easily measured in the field and a standard testing protocol should be released in the next 2-3 weeks from the ANSI/APSP-7 committee.
Recently I traveled with several National Award-Winning builders in Florida and visited about a dozen pools. (if any of you chose, please comment). EVERY pool tested had 4-8 times the necessary water for circulation! We were astonished to find out that they had been over pumping pools for this long. We performed a very simple measurement of flow rate (I’ll cover this completely in a later webinar) and it was enlightening to him to say the least. The smallest pump we measured was a ¾ HP and it was producing 75-85 GPM depending on piping configuration. That is not a lot of water, but it was on a 7000 gallon pool or a 1.5 hour turnover! Wonder what those 1 ½ and 2 HP were pushing? I think you get the point.
In closing I want to be certain that you take away two very important thoughts:
1) The pool cover you are servicing MUST be designed to work with the manufactured/field built sump you are replacing in order to meet the standard.
2) The cover must also be rated for the MAXIMUM flow rate on your system. Most pumps are moving a LOT more water than you think. The days of “selling on HP “ are gone and we need to focus on the pumps flow rate, which is tied to the specific piping of the pool. IF you don't measure the flow rate, YOU DON"T KNOW
what it is - measure it
We will cover this subject in much more detail over the upcoming weeks. Until then, let's all keep swimming pool safety at the forefront of our business and the industry.