ANG_hangar_study_recommended_changes_.docx

For hangars currently under design or construction, the following modification/additions to the existing ETL 02-15 and ETL 01-1-1 are recommended to increase the reliability of the foam/water system and mitigate inadvertent activations. Most of these recommendations will be required to comply with the pending UFC 4-211-01:

1. Provide NEMA 4 pull stations and backboxes, conduit looped into bottom of backbox with drain, dedicated distinct signage. (recommended to reduce inadvertent discharge from water intrusion, and provide a mean for condensate drainage in the raceway system.)

2. Provide NEMA 4 dead-man stop stations and backboxes, conduit loop into bottom of backbox with drain, dedicated distinct signage. (recommended to provide a means to stop or prevent foam/water discharge when the hangar is occupied.)

3. Provide watertight conduit and NEMA 4 J-Boxes in throughout hangar bay. (recommended to reduce water intrusion, and mitigate condensation on the interior of the raceway system.)

4. Provide cross-zoned optical flame detectors (Det-Tronics X3301), all locations within 5 ft of the hangar perimeter covered by at least three detectors. (Recommended to reduce the time required to activate the foam/water system during fire incident, and decrease the inadvertent discharges by cross-zoning all automatic initiating devices.)

5. Foam/water system will not be release off sprinkler water flow. (Recommend for alarm only, but not actuation of the foam/water system. This will reduce inadvertent discharges from misuse of drains or inspector test connections, or breaks in the overhead wet-pipe sprinkler system piping.)

6. Heat detection in the hangar bay is not required where a wet-pipe hangar bay sprinkler system is installed. (Recommend the heat detection system be removed where wet-pipe systems are provided, as this would be redundant to the optical flame detectors. Additionally it would be extremely unlikely the heat detection system would ever operate quicker than the optical flame detection.)

7. Where pre-action systems are installed, cross-zoning is not required for activation by the heat detection system. (Since the heat detection system is no longer used for releasing foam, it is recommended a single heat detector be allowed to release the pre-action system.)

8. Hi-Ex releasing panel shall be a Det-Tronics Eagle Quantum Premier. Panel shall be located in a normally occupied conditioned area. (Recommend locating panel in normally occupied conditioned area to increase longevity of the system and reduce corrosion and condensation on the interior of the panel.)

9. Provide SPD to protect the releasing panel, mounted in an independent enclosure, UL 1283 and 1449 listed. (Recommend to decrease system releases due to lighting strikes on the building and voltage surges on the power supply.)

10. Provide stainless steel piping and valving from the riser to the foam bladder tank. The pressurization line will connect to the system riser downstream of the flow control valve. (Recommended to minimize leaks from gaskets under constant pressure on the foam system, and safeguard the pathway the water needs to pressurize the bladder tank.)

11. Provide a flow control valve for foam/water riser with trim package for electric releasing, remote re-setting, and adjustable opening/closing speed control. Valve shall have the capability of closing in 15 seconds when the foam stop button is depressed, and opening in under 5 seconds when released. (Recommend to allow for the system to be stopped remotely through the use of the foam stop buttons.)