Fabric Expansion Joint

More Information

Fabric Expansion Joint Types of Fabric Expansion Joints Parts of Fabric Expansion Joint System Designs For A Variety Of Applications Design of Frame Refer to Ducting Design Concept based on surface Energy balanced Fabric Expansion Joint Movement Properties Of Elastomers and Fluoroplastic Construction of Keyser Fabric Expansion Joint Fabric Expansion Material Composition Heat Sealer Equipment Accessories

Parts of Fabric Expansion Joint System

  

A. Outer Cover
Outer Layer use material Glass Fiber coated or laminated by Fluoroplastic (PTFE) Fluoroelastomer (FKM), Silicon or others. Primarily functions as a protection against ambient, weather and mechanical influences, and as a pressurized reinforcement.

B. Back Up Flange / Back up Bar
Back up flange tighten fabric expansion joint to metal frame by bolt & nut system, other tightening system use strapping band. The edge of flange contact with expansion joint should have radius.

C. Inner Layer
Act as Mechanical Protection and maintain shape of expansion joint. Inner layer consists of glass fabric or ceramic fabric and stainless steel wire mesh (For abrasive media or negative pressure, wire mesh should be included)

D. Insulation & Gas Tight Layer
Used for thermal protection for temperatures above 400˚C & gas leak barrier to convey corrosion media or as chemical barrier.

E. Reinforcement Flange / Cuff / Backing Bar
As mechanical protection, thermal protection acts as gasket of the fabric expansion joint in the flange area

F. Metal Frame
Metal Frame can be designed for the bolt & nut or welding. Material selection need to be considered based on operating & design condition, care must be taken when different materials are being joined by welding (ASME Code). Other considerations will be required to avoid stress & heat concentration due to sharp corner or un-transferred heat.

G. Bolster/Inside Insulation / Cavity Pillow
Bolster should be used to reduce temperature and avoid heat losses for system. Bolster will protect fabric expansion joint against abrasive media, accumulation of ash and thermal shock due to unburned fuel.

H. Metal Liner/Baffle Plate/Sleeve
Metal Liner are metal shields designed to protect the flexible element and cavity pillow against fluttering caused by air turbulence, it can also be employed as thermal protection system.
Style of metal liner are : Straight, Air Flow, Telescopic (Double) and Floating. Installing it can be welded, tightened by bolt & nut, or designed as integral of the expansion joint frame.

I. Dust Seal
Dust seal was made from Stainless steel wire mesh rope braided and filled by ceramic blanket or stainless steel fiber. Installing it by spot or tack welding on one side between plates of double metal sleeve liner.

J. Ducting Insulation
Ducting insulation should be considered properly to maximize life time of expansion joint and frame. Its function are as follows : Avoid heat loss for high temperature application, Reduce condensation caused by dew point of media temperature, Reduce temperature in the bolster to acceptable level such that heat can be transferred through frame to minimize heat concentration and safe for outer cover of fabric expansion joint