Welcome to the second edition of Damper Application and
News. This newsletter is for the users and suppliers of
dampers and equipment for flue and process gases.
In this edition we are trying out a new format. Click
on the headlines below to take you to the full text.
THIS EDITION’S NEWS & ARTICLES
There were many new subscribers to the newsletter
joining the over 800 already receiving it. If you know
of anyone that might benefit, please forward a copy of
the newsletter to them.
Welcome Our First Sponsor – High Temp Bearings, Inc.
High Temp Bearings, Inc. specializes in providing
solutions to high temperature bearing applications.
Formed in 2001, it is a leading supplier of carbon
sleeve bearings to the Power Industry. Their success is
based on a simple plan, providing quality products at a
competitive price and backing it up with available
To compliment their carbon sleeve bearing product, High
Temp Bearings, Inc. has a full line of mounted ball
bearings, split housed tapered roller bearings, rod end
bearings, shaft collars and other related products.
Their bearing products accommodate shaft sizes from 1/2"
to over 14".
Newly offered is their NT self aligning bearings.
Please see the new product highlight below for more
Visit their web site for more information at
New Product Highlight -
NT Bearing Technology
Until now, damper companies and others, had to rely on
self-aligning graphite sleeve bearings for their high
temperature and/or low maintenance bearing needs.
There have been many cases where these bearings seized
or froze in the field, preventing operation of the
equipment. The HTB Corporation did extensive
case studies investigating the causes of damper shaft
seizures and then developed a product engineered to
address these issues, the NT bearing.
The heart of the NT bearing is a modified PTFE composite
system that is designed to offer all of the well
established, low friction, excellent corrosion
resistance, and high temperature performance of PTFE but
with greatly enhanced mechanical properties. PTFE and
its composites have been well established in critical
applications ranging from high pressure gaskets to harsh
chemical processing and handling.
The NT, self aligning sleeve bearing is a complete
replacement for non-precision, intermittent and
continuously operating systems utilizing graphite at
continuous temperatures up to 500 F˚ and speeds less
than 100 RPM's. This is idea for louver, butterfly and
guillotine dampers, as well as many other applications.
The patent pending NT bearing sleeve offers the
Continuous operating temperature of 500 F˚ with
intermittent service up to 630 F˚.
Enables the use of carbon steel shafting where
stainless was required to prevent binding with
Has extreme resistance to chemical and environmental
attack and will not cause other materials to
Eliminates the risk of seizing due to contaminate
build up in the shaft to bearing interface.
Has a very low coefficient of friction (0.06-0.360),
and significantly reduces the force required to
actuate a loaded shaft versus graphite.
Has been engineered to resist cold flow at elevated
FDA approved material for direct food contact.
No change in installation or housings from
traditional graphite sleeve bearings.
Maintenance free design.
Available in any standard bearing size and housing.
Cost effective replacement for graphite.
configurations are pillow block, 2 bolt flange, and 4
bolt flange. These accommodate shaft sizes from 1" to
3" as well as metric 25mm to 78mm. Contact
HTB for other sizes.
Visit the NT Bearing Technology web site for additional
information including Chemical capabilities, Mechanical
Properties, Thermal Properties and Case Study at
Common Failures in
Reliable dampers are important to the operation of power
and process systems. There are many variables in damper
and manufacture which ultimately determines the success
or failure in a specific installation. In order to have
confidence in the proper selection of damper equipment,
it is important to understand where problems have
occurred and to see how damper manufacturers address
these areas. One of the most common reason for failure,
is the use of dampers under-designed for the actual
application they are being used for. Clear definition
of the operating conditions need to be provided in your
request for quotes.
Linkage misadjusted or losses by vibration.
Lightweight link bars prone to buckling.
Bearing fouled with flyash causing binding.
Bearing/Shaft thermo expansion binding.
Leakage though poor packing glands.
Actuator undersized for actual service conditions.
Non-Repeatable limit switches, gear failures,
Flyash build-up causing obstruction in seal areas.
Over-rotation of blades causing poor sealing.
Blade ends jamming against side frames.
Distortion and warping caused by heat or pressure.
(click to enlarge)
Everyone knows the old adage "you get what you pay
for". However, you certainly don't want to buy more
than you need. A good quality damper will last the life
of the plant with minimum maintenance. A few basic
steps will insure your get the right damper:
Step 1 - Provide
accurate operating and design conditions. Indicate if
it is a clean system or if it has flyash or other
particulate in it. Include all upset conditions.
Step 2 - Determine the level of
performance needed: speed, frequency of operations and
allowable leakage. Higher performance costs more and is
usually harder to maintain.
Step 3 - Select
equipment best suited for the application better. For
example, louvers for control and guillotines for
Your damper manufacturer can help you summarize criteria
and develop a successful purchase and installation.
News Release and Articles Welcomed
If anyone has any ideas, news releases, or wish to
contribute an article please send it to
I would also like to recognize individuals who
contribute to this industry and perhaps are in the
background by giving them a spot light in this
newsletter. If you have a vendor or fellow employee you
would like to see recognized, please send us an email.