Expansion joints are extremely important because they allow for the accommodations of temperature changes. Changes in temperature can cause problems or destruction. There are a few different types of expansion joints, this article will discuss high temperature expansion joints specifically.
PES uses HOLZ Rubber Company’s high temperature expansion joints engineered for the most severe application and built with a combination of the most advance materials to ensure long life and predictable performance. HOLZ commitment to research and development has resulted in the highest performing product offering available for high temperature environments. We offer a full range of complete metal frames, assemblies and hardware.
Advantages of Fabric Expansion Joints
Advantages of fabric expansion joints include:
- Corrosion resistant
- Sound & vibration elimination
- Can withstand temperatures over 2000°F
- The number of expansion joints is reduced because of multi-plane movement
- Shortens face-to-face compared to metal
- Reduce the need for costly toggles, hangers, guides, etc.
- Cuts engineering time significantly
Rubber Chemical-Resistant Expansion Joints (Series 300 LT)
The rubber chemical resistant expansion joint is designed for use in wet or dry service up to 300°F and 5 psig. It is manufactured from multiple elastomers and offered in other belt or flanged configurations with single or multiple layers of woven fabric or knitted wire. This expansion joint is designed to operate without flowliner, except in abrasive or high velocity flow scenarios, and allows external insulation over the flex element if desired.
The typical applications for this expansion joint include:
- Baghouses
- FD fans
- Wet or dry scrubbers
- Precipitators
DuPont-Certified Viton® Expansion Joints (Series 400LT)
The DuPont-Certified Viton® expansion joint is designed for use in wet or dry services up to 400°F and 5psig and to operate without a flowliner except in abrasive or high velocity flow scenarios. It is offered in either belt or flanged configurations with reinforced single or multiple layers of woven fabric or knitted wire. Additional FEP or PTFE gas barrier is available to increase chemical resistance where ammonia slip is expected. This expansion joint can experience excursion temperatures up to 750°F in the case of air heater failure for a shorter duration.
Typical applications for this expansion joint include:
- Gas outlets
- Baghouses
- Precipitators
- Induced draft fans
- Wet or dry scrubbers
- Stack breeching ducts
Fiberglass Reinforced PTFE Expansion Joints (Series 5ooT)
This type of expansion joint is designed for use for wet or dry services up to 575°F and 5 psig. With a zero porosity gas barrier of varying thickness ranging from 5mils to 30mils, this expansion joint is constructed from fiberglass reinforced PTFE and mechanically bonded to the substrate. Consisting of the highest resin content in the industry, the fiberglass reinforced PTFE expansion joint is primarily used to provide the outer cover and gas seal for high temperature composites, but can also be used in extreme chemical service as the primary flex element or inner gas seal. It requires a flow liner in most cases if using a single layer solution. Typical applications range from paper processing liquors to wet scrubbers.
Multi-Layered Expansion Joints (Series 500HT – 1000HT)
The multi-layered expansion joint is designed for high temperature air and gas applications up to 1000°F. It is constructed from multiple layers based on design temperature requirements utilizing components including gas barrier, insulation, woven fabric and possibly knitted or woven wire mesh. A flowliner is required and it should not be externally insulated. The outer cover can be constructed using several different materials including EPDM, Viton, PTFE or metal alloys based on design conditions. Typically, this expansion joint is manufactured for economizer outlets, SCR inlets, secondary air and other hot flue gas applications.
HTG Extreme Temperature Expansion Joints (Series 1200)
The HTG extreme temperature expansion joint is specifically designed for gas turbine applications where temperatures are above 1000°F and heavy cycling, radial growth and large movement is expected. These expansion joints are designed to provide long life, easy installation, low external temperature and reduced noise. HTG expansion joints are found on GT exhaust, HRSG inlets and other high temperature applications. It is designed for ducting and fan applications.
If you need your expansion joint replaced or repaired, PES has you covered! Contact us today with the link below for more information!
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