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| TYPICAL FIELDSOF APPLICATION |
ULTRA LOW LEAKAGE DAMPERS
CIRCULAR INDUSTRIAL
POSITIVE SEAL VALVE (DAMPER) |
• ANIMAL VIRUS LABORATORIES
• BIOLOGICAL & PHARMACEUTICAL LABORATORIES
• CHEMICAL, BIOLOGICAL & RADIOLOGICAL FILTER SYSTEMS
• CHEMICAL LABORATORIES
• WATER TREATMENT PLANTS
• DEFENCE INDUSTRY
• MINING INDUSTRY
• NUCLEAR GENERATING STATIONS
• PETRO-CHEMICAL INDUSTRY
• SUBWAY TUNNEL VENTILATION
• FIRE DAMPERS
• BOILER APPLICATIONS |
EBA’s 12-inch Circular Industrial Positive Seal Valve was
tested for 250,000 open/close cycles by an independent
testing laboratory. (This number of cycles could represent
100 years or more of normal field operation). Using the Pressure
Decay Method*, the valve’s leakage test result was
2.18 x 10-5 cfm at 10 inch W.G. pressure differential
(1.03 x 10. -8m3/s at 2.5 KPa). |
SQUARE INDUSTRIAL
POSITIVE SEAL DAMPER |
EBA’s engineering team has tested a series of 4-foot x
6-foot (1219 mm x 1829 mm) damper banks each consisting
of six 24-inch Positive Seal Dampers controlled
by three jackshafted N.C. spring return actuators. Using
the Pressure Decay Method*, the damper’s average
leakage was 1.47 x 10-5 cfm/ft2 at 10 inch W.G. pressure
differential (7.47 x 10-8m3/s/m2at 2.5 KPa).
*The Pressure Decay Method determines the leakage
rate of a damper or housing by the change in air pressure
within an enclosure over a period of time. The leakage
rate is calculated by taking into account factors such
as air temperature, barometric pressure, change in
absolute pressure, air volume and duration of the test.
(As per ANSI/ASME N510). |
| HIGH PRESSURE APPLICATIONS |
EBA dampers and circular valves can both be custom built
for high pressure systems above 10 inch W.G. (2.5 KPa). |
| HIGH TEMPERATURE APPLICATIONS |
EBA dampers can be used at temperatures of up to 7500
F (4000 C) for continuous exposure and 10000 F (5400
C) for intermittent exposure. Leakage rate at very high
temperatures depend on the gasket material used. |
| FIRE DAMPERS |
EBA Damper technology can be adapted to fire dampers
for specialized nuclear and industrial applications. |
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| GENERAL DESCRIPTION |
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CIRCULAR INDUSTRIAL
POSITIVE SEAL DAMPER (VALVE) |
EBA’s Circular Industrial Positive Seal Damper
(valve) is designed for sealing round ducts and
pipes.
This damper is available in six standard sizes, 12,
16, 24, 36, 48 and 60-inch diameters (305, 406,
610, 914, 1219, and 1524 mm respectively). It is
equipped with two flanges for easy field connection
to flanges of round ducts and pipes. Special
sizes and flanges can be provided. |
| NOTE A: |
The rotating disc is controlled by an
actuator located outside of the air stream through
a jackshaft sized to prevent distortion during
operation. This ensures a tight seal. The integrity
of the damper housing, at the point where the
jackshaft penetrates, is achieved through EBA’s
exclusive tandem seals. The seals can be serviced
from outside the damper housing. |
| NOTE B: |
Materials of construction.
Casing: Mild steel or 304 stainless steel.
Dish: Spun galvanized or 304 stainless steel.
Shaft: 304 stainless steel.
Linkages: 304 stainless steel and high
density polyethylene.
Gasket: Extruded neoprene or silicone.
Bearings: Nylon.
Tandem seal casing: 304 stainless steel.
Tandem seals: Nitroxile
Other special materials such as 316 stainless
steel construction is available. |
| NOTE C: |
Left or right handed actuator
mounting is available. |
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SQUARE INDUSTRIAL
POSITIVE SEAL DAMPER |
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EBA’s Square Industrial Positive Seal Damper is
designed for use as a single damper in duct-work,
or grouped to form a rectangular damper bank of
virtually any size.
The square damper is available in four standard modules:
12, 16, 24 and 36 inches (305, 406, 610 and 914
mm respectively).
For damper banks larger than 36” x 36” (914 mm x 914
mm), multiple Positive Seal Damper modules would
be assembled together within a common frame and
shipped as a single assembly to ensure that the quality
and integrity of the end product is maintained. |
| NOTE A: |
The rotating disc is controlled by an actuator
located outside of the air stream through a jackshaft
sized to prevent distortion during operation. This
ensures a tight seal. The integrity of the damper
housing, at the point where the jackshaft penetrates,
is achieved through EBA’s exclusive tandem seals.
The seals can be serviced from outside the valve
housing. |
| NOTE B: |
Materials of construction.
Casing: Mild steel or 304 stainless steel.
Dish: Spun galvanized or 304 stainless steel.
Shaft: 304 stainless steel.
Linkages: 304 stainless steel and high density polyethylene.
Gasket: Extruded neoprene or silicone.
Bearings: Nylon.
Tandem seal casing: 304 stainless steel.
Tandem seals: Nitroxile
Other special materials such as 316 stainless steel
construction is available. |
| NOTE C: |
Left or right handed actuator mounting is available.
Pre-drilled holes can be provided on the damper flanges as an optional item. |
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FEATURES OF INDUSTRIAL
POSITIVE SEAL DAMPERS |
ULTRA LOW LEAKAGE |
Unique leakage rate of less than 1 x 10-4 cfm/ft2 and zero bubble
leakage at 10 inch W.G. (5 x 10-7 m3/s/m2 at 2.5 KPa) is
achieved due to EBA’s innovative rotating disc and extruded
neoprene or silicone bulb lip seal. |
| RUGGED CONSTRUCTION |
Construction is galvanized or stainless steel to meet
customized requirements. |
ACTUATORS - DEPENDABLE & VERSATILE
ACTUATORS IN OR OUT OF AIRSTREAM |
The standard location of the actuator is outside the airstream
for easy accessability as well as to prevent premature actuator
breakdown in corrosive environments. Alternatively, actuators
can be supplied in the air stream if required.
Multiple dampers can be operated with one single actuator
for damper bank applications. |
JACKSHAFT SEALS -
AIRTIGHT & DEPENDABLE |
EBA has developed a virtually leakproof seal around the jackshaft.
A casing of 304 stainless steel construction for tandem
nitroxile seals is continuously welded to the housing or frame
of the damper. Other seal materials are available to suit the
application. This sealing arrangement has been twice tested
for 250,000 open/close cycles. In both tests the seals showed
no deterioration upon completion. |
| NOTE: EBA |
excels in adapting existing products for new
usages or in developing innovative systems for new or
difficult applications. |
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| EXAMPLES OF APPLICATIONS |
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| DAMPERS FOR THE NUCLEAR INDUSTRY |
EBA’s Quality Assurance Program complies with the strict
requirements of CAN3-Z299.3-85. This allows EBA to supply
dampers to the nuclear industry which can also be
seismically qualified.
The quality of the dampers is ensured through a technically
sound and innovative product design that has been
rigorously tested. The resultant leakage rate, which is well
below that attained by competitive products, makes EBA’s
Industrial Positive Seal Dampers eminently suitable for
nuclear applications, such as:
• Standard Ventilation Systems
• Engineering Safety Feature Systems (ESF). |
| WHY AIRTIGHT DAMPERS? |
| certain ESF Systems, both face and by-pass dampers are used. During normal operation, the bypass dampers are open and the face dampers are closed to prevent contamination of the charcoal filter banks by moisture present in the air. During emergency or incident conditions, the face dampers open to permit filtration of the contaminated air by the activated charcoal. Simultaneously, the by-pass dampers are closed to ensure that none of the contaminated air by-passes the charcoal filters.Airtight dampers thus prolong the time-interval for the change of charcoal by eliminating contamination during normal operation. Airtight dampers also ensure that none of the contaminated air by-passes the charcoal filters.Costs associated with the replacement and disposal ofthe spent charcoal for an ESF System with Type III High Efficiency Carbon Absorber bed are in excess of $100,000.More importantly, if a Power Plant has to shut down for several days to carry out the charcoal filter change, several million dollars in lost revenues can be directly attributedto poor sealing by dampers. |
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