Dear Forum members, I have got the following situation.
A 4 years old system, grid type, 2" galvanized pipes, K=5.6 pendent sprinklers, bulb type. Suspecting that there is a great deal of clogged heads, we run some tests: 1. We subjected a sample to 15 psi pressure and initiated the bulbs. 2. Some of the heads burst. Some did not. 3. One head burst at 14 bars, one at 3.5 bars, one at 1.5 bars. 4. In the sprinklers that bust, the cone type plastic plug was ejected, but the deposit did not, i.e.: The actual nozzle was about 1/4 of the full sprinkler bore area. We tested the water. The general solid contents were between 277 and 455 mg/L. Ca was between 55 and 82 mg/L, Mg 32 to 37 mg/L. Cl 25 to 27 mg/L Na 14 to 17 mg/L Zn 3 to 6 mg/L We also tested the deposits within some sprinklers that appeared to be hard (resulting in a constricted nozzle). In these deposits we found a great deal of Iron and Zinc. In the deposit one head we found 4% Ca, 50% iron and 4.4% Zinc, In another one 10% Ca, 1.5% Iron and 20% Zinc. Another one 4.5% Ca, 25% Iron, 8% Zinc. All came from the same galvanized system. This is all very disturbing information. It appears that Zinc and Iron ions migrate to the copper based sprinkler and creates hard deposit de-capacitating the sprinkler system. I would like to hear from other people experience and source of information for similar research. After all, under NFPA25 one is not supposed to inspect the condition of sprinklers by dismounting a sample. DAN, Dan Arbel Tel: 972-4-8243337 Fax: 972-4-8243278 M: 972-52-2810593 _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
