Posted by Ray Cronise on October 29, 2008 at 8:30am
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 tests.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:
Example Spa Cover with Field Fabricated Sump - This is a tough call on what cover to useFinally 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.
Tim,
I'd like to "offer a second eye" on your form. I believe a thorough assessment needs to be done by a qualified/certified individual before any repairs/upgrade/installations are done. You are absolutely correct in that every vessel in different in some form or another; therefore possibly requiring a different solution. I'd really like to discuss this further with you.
Also a good question regarding the sale of a home. Maybe Stephen Getzoff will interpret for us.
Glad to hear someone else has recognized the GPM issue. We are currently working on a comprehensive evaluation form for pools in general. Although I am sure I will be editing it, I am up to page 10 and might be complete with 12 pages. This is to walk into any facility/home and evaluate any "vessel" (pool, spa, waterpark, etc....) that might be on site. We are presenting this to clients, indoor commercial facilities first, that every vessel is different and may require a different solution for each. This evaluation will include a scuba evaluation, to measure grates and sumps, but also count returns and trim them for balance. Additionally we will be measuring pump performances based upon pump curves and testing with quality gauges at pump influents and effluents to get "real" gpm performances with all standard suction modes as well as surface suction alone performances. Anybody interested in offering us a second eye on this form?
Question: As I read the VGB Act it says something to the effect that states" entered into commerce" . This reffering to products to be sold after Dec. 20, 2008. If someone is selling a home without meeting VGB criteria improvements then are they entering that non conforming pool, portable spa or other vessel into commerce as part of the sale of the home?
That article in Watershapes was fantastic and I am so glad someone with knowledge is coming out on the subject. I no longer build pools but I keep on top of the information and this is a topic that has pestered me for years, I used to build with out main drains and always wondered why others were stuck in the old ways. I actually started building without because of the failure rate in the Northeast with freezing and difficult repairs when they do fail. This is great stuff and I am glad too see you bringing it to the front.
Ray is absolutely correct - he came to Florida a few weeks ago and actually field tested pools all across the State. The result was an incredible eye-opener for the pool contractors he worked with; the revelation was that we, as an industry, have been radically over-sizing our pumps for years. The ability to field verify, with a very simple, soon to be revealed tool, assembled from local hardware store parts will be a game changer for our industry. This is going to be a giant leap forward in suction outlet safety (with a side benefit of energy efficiency). You'll be impressed - I was!
We will be covering this shortly! The great part is that we HAVE a solution...it is coming out of committee now and it is EASY and Cheap to implement on new OR existing construction.
I would say keep watching and you should see something in the next 14 days.
Thank you for your response! And you are making perfect sense to me too, I always wondered why my local jurisdictions put so much emphasis on the numbers. Even when I began my training I had a strange feeling I was being handed a dusty antique.:) You have presented some compelling evidence my friend. Channeling Williams-Hazen and some rough theories may bring a logical design but, like you said, its only an estimate. As built testing prior to close-out should absolutely be mandatory.
So now I want to know about the latest methods, practices, and criteria for verifying safety and releasing a project for close-out.
Comments
I'd like to "offer a second eye" on your form. I believe a thorough assessment needs to be done by a qualified/certified individual before any repairs/upgrade/installations are done. You are absolutely correct in that every vessel in different in some form or another; therefore possibly requiring a different solution. I'd really like to discuss this further with you.
Also a good question regarding the sale of a home. Maybe Stephen Getzoff will interpret for us.
Question: As I read the VGB Act it says something to the effect that states" entered into commerce" . This reffering to products to be sold after Dec. 20, 2008. If someone is selling a home without meeting VGB criteria improvements then are they entering that non conforming pool, portable spa or other vessel into commerce as part of the sale of the home?
I would say keep watching and you should see something in the next 14 days.
So now I want to know about the latest methods, practices, and criteria for verifying safety and releasing a project for close-out.
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