Good morning all! Hope everyone had a WONDERFUL Christmas.
Let's start off the week with a HIGHLY technical aircraft hangar group of questions that I am sure this esteemed group can adequately handle ;-) Scenario: Group-1 Aircraft Hangar Large Hangar - In excess of 40,000 sq.ft. Tail Height - In excess of 28 ft. Wing Surface Area - In excess of 3000 sq.ft. NFPA-409 allows a choice of three (3) protection criteria: Criteria #1 - Foam-water deluge system with a supplementary protection system. (Read under wing monitor nozzles or other approved protection) Criteria #2 - Wet Automatic sprinklers AND an automatic low-level low-expansion foam system. Criteria #3 - Wet Automatic sprinklers AND an automatic low-level high-expansion foam system. (Low-level meaning a minimum 2ft of depth of the foam blanket to accomodate any flammable/combustible liquids pool fire at the floor level.) Question #1: Based on these protection scheme choices am I correct in my interpretation that the under wing supplementary protection system is ONLY required if Criteria #1 is chosen as the protection criteria for this hangar? Question #2: When utilizing Criteria #3 (High-Ex Foam), am I also correct in my interpretation that the foam solution requirement is the total AREA of the aircraft hangar x 3 cubic feet/min/square ft or 132,000 cfm (44,000 sq.ft. hangar) Question #3: When utilizing Criteria #3 (High-Ex Foam), am I also correct in my interpretation that the sprinkler breakdown factor of 10 cfm/gpm is calculated based on the TOTAL sprinkler system density and demand area requirement of .17 / 15000? (.17/15000 = 2550 gpm x 10 cfm = an additional 25,500 cfm of foam solution) Question #4: When utilizing Criteria #3 (High-Ex Foam), am I also correct in my interpretation that the foam solution shrinkage factor is 1.15 x the SUM of Question #2 and #3 above? (132,000 + 25,500 = 157,500 x 1.15 = 181,125 cfm total foam solution requirement) Question #5: What is the most common detection and releasing method for the hi-ex foam generators? Question #6: How is the column protection requirement normally handled with a Hi-Ex foam system and a wet automatic sprinkler system? I am also providing two (2) foam-water hose reel stations at 60 gpm each for a duration of 20 minutes and two (2) fire pumps. Please offer any advise or direction you may have based on your experiences with this particular scenario. Thanks, Ray Vance - SET Chief Sales Designer Wayne Automatic Fire Sprinklers, Inc. www.waynefire.com<blocked::blocked::blocked::blocked::blocked::blocked::blocked::blocked::blocked::blocked::outbind://37/www.waynefire.com> 407-877-5563 office 321-436-2184 mobile _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.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)
