I hate to say, but as a local AHJ I did not spend much time listening to why do I have to put in backflow. The answer is the State Department of Health requires it if you are going to make direct connection to the municipal water system. Complaining to me about it is like complaining to the waitress about the pothole in the restaurant parking lot. Neither has an influence to affect the issue. Why it is a good idea to waste everyones' time rehashing the issue at the counter is beyond me.
If the sprinkler industry wants to affect this they should at industry level fund independent academic research at the PhD level and that withstands the scrutiny of pre-publish peer review and then comment post-publishing in an appropriate scientific journal. Then go back to the parts of the EPA that administer the drinking water portions of the Clean Water Act. Get NFSA and AFSA together and go at it. Even at the State-level of DOH this is quickly the level of education that you encounter. They've all peer review published. They are not impressed by how many sprinkler plans you've stamped or main drain tests you've conducted. Have you gone upstream of connection to fire sprinkler system and sampled and conducted analytic tests to accepted standards on the samples? The level of lab experience to do all this is not the same as that required to use a Potter MIC test kit. bv ----- Original Message ----- From: "Dwight Havens" <[email protected]> To: [email protected] Sent: Tuesday, July 23, 2013 6:17:11 PM Subject: Re: SIGN for Backflow Prevention Assembly Forward Flow Test First, let me say that I do not believe that BFPA’s are really necessary to protect the public water supply for Class 1 and 2 fire protection systems. We won that battle twice in Arizona, but the water purveyors ultimately prevailed, so the war is over. Our concern is that these devices be as reliable as alarm check valves and not cause automatic sprinkler systems to fail. Tell me the utility of this information. It is nice to know but has no purpose. Like the main drain test, it is only of value if you have the previous tests to compare it to. Where does the system test flow rate come from and at what pressure? Remember those hydraulic calculations that had to be done to show the water supply was adequate to meet the system flow and pressure demands? It’s in there. Does that pressure compare to the upstream residual, the downstream residual? If the government requires you to analyze the data to determine if there is a problem, the upstream and downstream residuals need to be equal to or greater than the values shown in the hydraulic calculations at the design flow rate. The delta across the BFPA needs to be less than or equal to the value from the manufacturer’s literature at the design flow rate (hopefully the number used in the hydraulic calculations). If you flow more than the design flow rate, the delta should be compared to the manufacturer’s literature in order to evaluate the results. What does this tell me the main drain test does not? The main drain test (if compared to previous main drain tests) tells you whether or not the water supply to the system has changed over time. The forward flow test of the backflow prevention assembly is specifically looking at any changes in the operation of the BFPA. When performing the main drain test, you flow whatever the supply can provide through the fully opened valve. The forward flow test of the BFPA specifies a minimum flow rate, which makes comparing “apples to apples” more difficult if you are trying to look at the state of the water supply. You have to throttle the flow to the design flow rate for consistent results. The failure of a backflow device to "fully" open is not a nuanced phenomena. They barely flow or they flow "fully" relative to available pressure less friction loss. This was a problem in the early days of putting backflows designed for plumbing and process piping, constantly dynamic water systems, on sprinklers, primarily non-dynamic systems. Things would rust and rubbers would stick. Newer, sprinkler purposed models do not exhibit these failures as often. Yes, some makes and models were simply awful, but because of the testing, the ones that were bad were recognized and no longer accepted. New models have come along with much improved reliability, but no one has compiled the reliability data to convince the committee to eliminate or change the frequency of the test. For some reason, once a requirement is in the standard, it becomes much harder to remove it. The federal government is correct that the test, as presented in the standard, does not require relevant data be collected and compared to previous tests, which makes it a useless test. What is the pass/fail criteria? My assumption is that they are trying to correct this oversight, since they cannot waive the requirement. As the AHJ, they can raise the bar by requiring the information be provided on a sign and specifying how the data is to be collected and evaluated, by including the requirement in the contract language, or a referenced standard. Dwight ________________________________ From: Ron Greenman <[email protected]> To: [email protected] Sent: Monday, July 22, 2013 9:17 PM Subject: Re: SIGN for Backflow Prevention Assembly Forward Flow Test Tell me the utility of this information. It is nice to know but has no purpose. Where dos the system test flow rate come from and at what pressure? Does that pressure compare to the upstream residual, the downstream residual? What does this tell me the main drain test does not? The failure of a backflow device to "fully" open is not a nuanced phenomena. They barely flow or they flow "fully" relative to available pressure less friction loss. This was a problem in the early days of putting backlows designed for plumbing and process piping, constantly dynamic water systems, on sprinklers, primarily non-dynamic systems. Things would rust and rubbers would stick. Newer, sprinkler purposed models do not exhibit these failures as often. But back to the sign. The information is nice, like the tach in my car. The car is automatic, shifting is controlled by the computer, and there is a rev limiter for when I shift it to the automatic manual mode I get information but it has value. Now I used to race motorcycles and my favorite had a very narrow rpm range (about 600). The tach was essential for optimum use of the gearbox whereas a speedometer would have been useless at best and a couple extra pounds of detriment. That speedo in my car though gives me info that helps me avoid a ticket. On Mon, Jul 22, 2013 at 5:15 PM, Dwight Havens <[email protected]>wrote: > Why is this information useless? The point of the forward flow test is to > ensure that the backflow device is opening properly. Like the main drain > test, the information is only properly assessed when compared to previous > tests. Initial system configuration (tests) are often documented at > acceptance, but rarely kept in a place where the information is available > in the field. This is one of the areas that is covered in the standard, in > which case the AHJ and the owner have every right to make the requirement > to facilitate proper assessment of the water supply to the system over time. > > > > > ________________________________ > From: Ron Greenman <[email protected]> > To: [email protected] > Sent: Monday, July 22, 2013 7:16 PM > Subject: Re: SIGN for Backflow Prevention Assembly Forward Flow Test > > > And apart from the uselessness of this information they want it because > they want it. I'd certainly like nonsense like this to be justified. I > certainly hope the request for this "extra" was clearly specified in the > bidding documents and that you were able to add the few dollars this will > cost accordingly. > > > On Mon, Jul 22, 2013 at 1:57 PM, Bobby Gillett <[email protected] > >wrote: > > > Brad, > > > > Your suggestion/question makes sense, however, this is a military base > and > > they are calling for this info recorded on a metal placard and placed on > > the backflow, for sure. > > > > Thank you. > > > > > > On Mon, Jul 22, 2013 at 3:34 PM, Brad Casterline < > [email protected] > > >wrote: > > > > > Just curious Bobby-- would this sign be for initial acceptance? It > seems > > > more practical to require similar to Main Drain Test tags- because > there > > > might be slight variations from test to test, and the metal one might > be > > > scrap metal down the road! > > > > > > -----Original Message----- > > > From: Bobby Gillett [mailto:[email protected]] > > > Sent: Monday, July 22, 2013 3:14 PM > > > To: [email protected] > > > Subject: Re: SIGN for Backflow Prevention Assembly Forward Flow Test > > > > > > Thank you Forest, as I mentioned before - We can make a sign, just > hoping > > > there were already some out there - looks more professional.... > > > > > > > > > On Mon, Jul 22, 2013 at 3:12 PM, Forest Wilson <[email protected] > > > >wrote: > > > > > > > Can you just make a sign using the back of a hydraulic call sign and > > > > permanent marker? > > > > > > > > Sent from my iPhone > > > > > > > > On Jul 22, 2013, at 4:04 PM, Bobby Gillett <[email protected]> > > > > wrote: > > > > > > > > > We have a project where the spec's are calling for us to install a > > > metal > > > > > placard on the backflow assembly with the pressure readings > upstream > > > and > > > > > downstream of the assembly, total pressure drop and the system test > > > flow > > > > > rate. > > > > > > > > > > Has anyone had to supply similar signs and know where we can get > > such a > > > > > sign? We could have some made, but why reinvent the wheel if you > > don't > > > > have > > > > > too? > > > > > > > > > > Thank you for your assistance in advance. > > > > > > > > > > Bobby Gillett > > > > > Living Water Fire Protection, LLC > > > > > (850) 937-1850 > > > > > _______________________________________________ > > > > > Sprinklerforum mailing list > > > > > [email protected] > > > > > > > > > > > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > _______________________________________________ > > > > Sprinklerforum mailing list > > > > [email protected] > > > > > > > > > > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > > > _______________________________________________ > > > Sprinklerforum mailing list > > > [email protected] > > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > > _______________________________________________ > > > Sprinklerforum mailing list > > > [email protected] > > > > > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > _______________________________________________ > > Sprinklerforum mailing list > > [email protected] > > > > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > > > > > > -- > Ron Greenman > Instructor > Fire Protection Engineering Technology > Bates Technical College > 1101 So. Yakima Ave. > Tacoma, WA 98405 > > [email protected] > > http://www.bates.ctc.edu/fireprotection/ > > 253.680.7346 > 253.576.9700 (cell) > > Member: > ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC > > They are happy men whose natures sort with their vocations. -Francis Bacon, > essayist, philosopher, and statesman (1561-1626) > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > _______________________________________________ > Sprinklerforum mailing list > [email protected] > > http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org > -- Ron Greenman Instructor Fire Protection Engineering Technology Bates Technical College 1101 So. Yakima Ave. Tacoma, WA 98405 [email protected] http://www.bates.ctc.edu/fireprotection/ 253.680.7346 253.576.9700 (cell) Member: ASEE, SFPE, ASCET, NFPA, AFSA, NFSA, AFAA, NIBS, WSAFM, WFC, WFSC They are happy men whose natures sort with their vocations. -Francis Bacon, essayist, philosopher, and statesman (1561-1626) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/listinfo.cgi/sprinklerforum-firesprinkler.org
