Page 6 - NG-1 100, NG-1 250, NG-1 500 - Wall-Mounted Nitrogen Generator System Installation Manual
P. 6

Oxygen Removal Vent
To completely remove the oxygen in a dry pipe or preaction fire sprinkler system, it is necessary to install a vent on the main riser of each fire sprinkler system. Vents allow for a system to breathe, which requires a 3-5 psig (.2-.3 bar) pressure range to facilitate removal of oxygen gas from the system. Supervisory nitrogen gas is supplied to the system until the air maintenance device reaches the high-end pressure. The vent slowly releases the gas mixture inside the sprinkler system through the restricted orifice until the system reaches the low-end pressure at which point supervisory nitrogen is supplied to the system again. This process is repeated numerous times until the atmosphere inside the piping network reaches at least 98% nitrogen. The vent is crucial for expedient mixing of the gas and elimination of oxygen inside the system within the specified timeframe. TYCO offers two (2) DPNI vents – the TSV-D SMART Vent and the TAV-D Vent. The TSV-D SMART Vent is an automated vent that when activated will open and vent for the necessary amount of time to achieve the desired inert inner pipe atmosphere, and close automatically when the process is completed. This process is initiated by depressing the “vent” pushbutton on the vent’s control panel. The TAV-D is a manual vent that requires an operator to open the vent’s isolation ball valve when venting is desired, and after a specified time (typically 14 days or less) when the breathing process is completed the operator must manually close the isolation ball valve on the vent.
Oxygen Removal Vent Features
The TYCO oxygen removal vents with the “fill and purge” breathing technology include the following features:
• Removal of corrosive oxygen from the entire sprinkler system in fourteen (14) days or less
• All equipment is installed in the sprinkler riser room for easier installation and servicing
• No support hanger required
• Backpressure regulator preventing system depressurization from vent
• In-line filter to protect restricted venting orifice from contamination Recommended Monitoring Equipment
In-Line Corrosion Detectors
The TYCO In-Line Corrosion Detector (TILD) is designed to provide an early warning of corrosion activity within the fire sprinkler system. The TILD features a double wall construction that incorporates a thin milled section of pipe (.035” (0.9mm)) surrounded by a full thickness piece of pipe to detect and alert to the presence of corrosion activity. If corrosion occurs the milled section of the TILD will fail prior to the failure of any other section of the pipe wall. When the milled section fails it allows the system to pressurize the chamber outside the milled section of pipe which activates the attached pressure switch on the TILD. The pressure switch can be remotely monitored through a building monitoring system, or locally through the TYCO Remote Test Station (TRTI) which is included with the TILD.
TFP1273 Page 5 of 80

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