The glass remains intact because of the location (close proximity) to the glass of the sprinkler heads. At 155'F/200'F the heads go off before the glass temp rises above that, due to the mass of the glass requiring longer than air to rise in temp. Also the distance from the glass to the sprinkler is on 1/2" to 4" so pretty much any heat the glazing gets the sprinkler gets. Glass is an Amorphous solid, with a very high melting point. (1800'F to make it a fused liquid.) So long before it would melt or drop out of the frame from the heat, the sprinkler would activate. Through testing TYCO has shown that with the proper placement and spray pattern the sprinkler spray cools the glass before it reaches a temperature that might cause the glazing to shatter.
Thom McMahon, SET Firetech, Inc. 2560 Copper Ridge Dr P.O. Box 882136 Steamboat Springs, CO 80488 Tel: 970-879-7952 Fax: 970-879-7926 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Fletcher, Ron Sent: Wednesday, October 01, 2008 9:10 AM To: [email protected] Subject: RE: Window Sprinklers So the test assumes the glass remains intact until sprinkler activation? Ron Fletcher Aero Automatic Sprinkler Phoenix, AZ _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [EMAIL PROTECTED] To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
