OLS Model SD60 Tunnel Ventilation Damper

“The OLS Model SD60 Tunnel Ventilation Damper is essentially a smoke damper in tunnel ventilation system.�
Tunnel ventilation dampers are designed for enclosed vehicular tunnels, enclosed parking structures, bus terminals and particularly for rapid transit system with long tunnels where mechanical ventilation becomes essential in order to supplement the natural ventilation from the piston effect of moving trains within the tunnel. This is to ensure that environmental pollutant level and temperature within such structures are maintained at acceptable levels. In addition, the dampers play a vital role in controlling the direction of airflow and migration of smoke within the tunnels during emergency ventilation activation as a result of fire within the tunnel. The emergency ventilation allows rapid removal of smoke and heat within the tunnel to permit safe evacuation of the train occupants and the entry of fire fighting personnel to the scene of fire.

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Figure 1 (left) shows a typical application of the tunnel ventilation dampers in a subway tunnel with combined natural and forced ventilation. During normal operation, damper 1 may be closed and damper 2 opened to allow the escape of contaminated air through the ventilated shafts. If necessary, damper 1 may be opened to allow for additional ventilation by the reversible flow fan.
During emergencies, when forced ventilation is required, damper 2 will be closed and damper 1 will be opened to allow for the removal of smoke and hear, or the supply of fresh air to the tunnel, depending on the locations of the stalled train and fire. The dampers on the ventilation shafts on the opposite end of the stalled train will be opened for smoke removal.
When interlocked with the tunnel ventilation system and integrated into the automation system for central control and monitoring, the tunnel ventilation dampers with externally powered electric or pneumatic actuators serve as live support systems in the subway tunnels. As tunnel ventilation dampers are used to control the movement of smoke during a fire, the dampers and their actuators must be able to operate at elevated temperatures and have a safety feature that allows them to assume the fail-safe position during power interruption. It is therefore important that tunnel ventilation damper is tested to appropriate standards for prove of its reliability as a smoke damper.

With OLS’s expertise and many years of dedication to research and product development, the SD60 tunnel ventilation damper is one of the many quality products that OLS has developed for the industry. Designed to suit exact applications, client’s specifications and statutory regulations, the SD60 tunnel ventilation damper has been developed for use in subways for underground tunnel ventilation systems that require heavy-duty dampers.

Features
• Tough & Enduring
OLS tunnel ventilation dampers with their heavy gage material construction and fully welded corners, provide strength and tolerance to endure rough site handling. The specially designed blades enable the dampers to withstand high-pressure fluctuations. The dampers have been tested to 6000-pascal pressure differential.
• Reliable & Superior in Quality
The high quality galvanized steel used for OLS tunnel ventilation dampers with stainless steel moving parts prevent the damper from seizure.
• Low Leakage
OLS tunnel ventilation dampers are designed to effectively seal openings when closed. This is an essential feature of smoke control and isolation dampers that are used in subway tunnels to control the movement of airflow and toxic smoke. Such safety design is important to prevent loss of lives during a fire. Standard dampers are able to provide air tightness of 99.86% (i.e. a leakage rate of 14 × 10-3m3/s/m2) based on duct design velocity of 10.2 m/s at 1000-pascal pressure differential across the closed damper or 99.99% (i.e. a leakage rate of 8 × 10-4m3/s/m2) based on duct design velocity of 10.2 m/s at 100-pascal pressure differential across the closed damper.
• Low Airflow Resistance
The aerodynamic design of OLS tunnel ventilation dampers with their airfoil blades present very low resistance to airflow. Designers should take note that pressure loss presented represents the damper characteristics and that system loss can be significantly higher.
• Performance Tested
OLS tunnel ventilation dampers and their actuators have been rigorously tested according to UL555s: “Leakage Rated Dampers For Use In Smoke Control System� for its reliability, temperature resistance, air tightness and ability to operate under dynamic conditions.
• Temperature Resistant
OLS tunnel ventilation dampers and their actuators are also designed to handle hot gases of temperatures ranging from 150°C to 250°C. for duration of up to 2 hours. This is possible because of the special components used and the ability of the dampers to absorb the thermal expansion in the presence of hot gases.
• Ease of maintenance & Installation
The damper frames may have pre-punched holes on them for easy installation. To install the dampers within building walls, sleeves may be used and they are provided with retaining angles for ease of installation. Due to the high quality material used for the dampers and its moving parts, the dampers are virtually maintenance-free. Though the dampers are designed to be maintenance-free, the dampers may be tested regularly to ensure proper functioning of the pneumatic or electric system, and that there are no obstructions to the blade movements. Tests can be carried out remotely if the dampers are installed with suitable limit switches.

OLS tunnel ventilation dampers come in modular designs, which can be easily assembled into larger dampers on site. For large dampers, designer and installer should take note that robust installation frames should be provided for assembly of the damper on site. The installation frame may be provided upon request at addition cost.
Download Tunnel Ventilation Damper catalog
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