Fabric Expansion Joints

Keyser Fabric Expansion Joints

Keyser Technologies leads the region in the design and manufacture of a comprehensive range of fabric expansion joints for all industries. Stringent tests and quality control measures ensures that the fabric expansion joints are of the highest quality. They are used extensively in industries like power plants, steel mills and smelters.

 

Keyser Fabric Expansion Joints are fabricated from a variety of non-metallic materials such as fabrics and insulation materials. Problems that are caused by mechanical and thermal stresses are solved with the use of Fabric Expansion Joints. They are customized according to clients specific request and requirements.

Keyser Fabric Expansion Joints are used in a variety of industries such as:

  • Fossil fired power plant
  • Oil & Gas
  • Fire Protection
  • Steel Mills
  • Pulp & Paper industry
  • Refuse incineration
  • Smelters
  • Cement Plant
  • Heat / Dust Recovery
  • Food-processing
  • Marine Offshore

Key Advantages For The Use Of Keyser Fabric Expansion Joints:

  • No transmission of stress
  • No transmission of sound & vibration
  • Larger movement allowances
  • Lower loads
  • High resistance to corrosion
  • High Temperature (over 2000 …F)
  • Higher efficiency at lower cost
  • Ease of Installation
Materials Used In Keyser Fabric Expansion Joints :

The performance of Fabric Expansion Joints for systems is determined by severity of the environment and by the selection of the materials for each component of the expansion joint. Fundamental requirements and temperature as well as chemical are important factors as well.

 

Fabrics are used for the reinforcement of elastomers and other coatings to yield the mechanical properties necessary to withstand the movements and pressures exerted. Insulation materials are use to reduce temperatures, optimize the performance and the life span of the elastomeric or coated material in the gas seal layer. Metal Flanges are used to connect the flexible element to the ductwork. Metal flow liners are used to protect the gas seal membrane and insulation layers of the flexible element from abrasive particles.

 

KEYSER Technologies work with reputable fabric manufacturers around the globe to produce the reliable and high quality fabric expansion joints.

Types of Fabric Expansion Joints

A) Single Layer Type:

This comprises with one or more reinforcement plies with coating of elastomers or fluoroplastics to form a homogenous material.

 

B) Composite Type:

This consists of various plies of materials which are laid one over another, usually bonded, sewn or joint together in the clamped flange area.

 

C) Anatomy of Type

1) F Type : Integrally Flanged Type Expansion Joint

2) B Type : Belt Type Expansion Joint

Keyser Offers Designs For A Variety Of Applications

Standard Internal Flanged Type (F Type) Expansion
  • Low to moderate temperatures application
  • Primary used for field installation application
  • Lower initial cost and shipping cost
  • Molded corners provided for rectangular
Economic Belt Type Expansion Joint
  • High temperature duct work application
  • Pre-fabricated flame reduce cost
  • Large lateral movement
  • Outside belt assembly
Belt Type Expansion Joint
  • Suitable normality temperature applications
  • Frequent fan application
  • Economic and Standard frame
  • Facilitate belt replacement
Shop welded flow liner
  • Low temperature application with low level
  • Future belt replacement
  • Used frequently with fan application
Pillow design
  • High temperature application and high level
  • Large Lateral Movements
  • Integral telescopic flow liners
  • Provide protection for belts and pillows
Large lateral movements
  • Single integral-flow liner
  • Low level and vertical duct work applications
  • Provide protection for belts and pillows
  • Future belt and pillow replacement
Facilitates field assembly
  • Well suitable field assembly installation
  • Utilized for all temperature ratings
  • Economic frame

Keyser Fabric Expansion Joints Movement

Movement Capabilities

Non-metallic ducting movements can be calculated on the design and maximum excursion temperatures. One unit of fabric expansion joint is able to handle combined axial, lateral, angular and torsional movements. The expansion joint are carefully placed to minimize the number of expansion joints required while absorbing all of the duct movements.

Fabric Expansion Joints Movements
Set Back Requirements:

Proper setback reduces the thermal transfer effect on the inner face of the expansion joint from particles in the gas steam. The expansion joint is moved outward from the gas stream to prevent the joint from protruding into the gas stream when operating under negative pressures.

Active Length:

Greater movements can be achieved by increasing the active length of the expansion joint.

Properties Of Elastomers and Fluoroplastic

* Fluoroelastomers when reinforced with nonreactive materials have an intermittent temperature capability
of 4 hours at 700…F and 2 hours at 750…F
** Excursions at high temperatures will have a detrimental effect on useful life of the product.
*** Any nuclear application should be referred to expansion joint manufacturer for specific elastomer recommendation.

 

Rating Code: A= Little or no effect
B= Minor to moderate effect
C= Severe effect

Commonly Used Reinforcing Material & Their Properties

(*) These temperatures are the maximum continuous temperatures that the reinforcement material can handle.

 

Rating Code: A= Little or no effect
B= Minor to moderate effect
C= Severe effect

Construction of Keyser Fabric Expansion Joint

1. Reinforcement added in the flange area, protects and isolates the Expansion Joint in areas that are in contact with steel parts.

2. Materials such as stainless steel or Incoloy wire mesh are used for the construction of the Expansion Joint. This further reinforces the unit with increased stability.

3. Life span of the Expansion Joint is increased with the use of internal sleeves. This gives extra mechanical protection to the unit well as the insulation bolster.

4. Back flanges may be supplied together with the Expansion Joints. The specification is dependent on the type of Expansion Joint required and their working environment.

5. Bolts & nuts may be supplied together.

6. The insulation bag/bolster is installed in the space left between the Expansion Joint and the inner sleeves. It is formed by an external folder made of wire mesh or fabric material. The insulation bag protects the Expansion Joint from mechanical damage. The protection against high temperatures and reduction of noise levels are other advantages. The insulation bags are designed separately to suit different operating conditions.

Materials Used For Keyser Fabric Expansion Joints

The performance of Fabric Expansion Joints for systems is determined by the severity of the environment and by the selection of the materials for each component of the expansion joint. Fundamental requirements and temperature as well as chemical are important factors as well.

 

Fabrics are used for the reinforcement of elastomers and other coatings to yield the mechanical properties necessary to withstand the movements and pressures exerted. Insulation materials are used to reduce temperatures, optimize the performance and the life span of the elastomeric or coated material in the gas seal layer.Metal Flanges are used to connect the flexible element to the ductwork. Metal flow liners are used to protect the gas seal membrane and insulation layers of the flexible element from abrasive particles.

 

KEYSER Technologies work with reputable fabric manufacturers around the globe to produce the most reliable and high quality fabric expansion joints.

Flex Test For Corrosion Barriers

Flex Cycles To Failure For Thin Perfluoroplastic Products

In Accordance With International Standard ISO 7854-1984 (E):
Rubber-or plastics-coated fabrics Determination of resistance to damage by flexing (dynamic method).

Fabric Expansion Material Composition

All fabric expansion joints is fully customizable according to client’s request and application requirements.

Glass Fabric Reinforced PTFE Layer

Description

1. KeyFlex Film 14-7 is a 1.2mm thick with 0.23mm LFP Multiple — Inter Layer material. It can bear high load under high temperature. One of the main advantage is its high resistance to tear.
2. KeyFlex Film 14-7 is a 100% pure PTFE material that is capable of resisting the stress-cracking caused by flexing and severe temperature fluctuation in expansion joint applications. The multi-diction strength and durability of LFP allows it to function as a crack free and flexible surface. The picture above show the two components not laminated for half the sample.
3. The toughness of the KeyFlex Film is proven by successful performance of the material in many industrial applications as a stand-alone product.

KEYFLEX 1405

Description

1. KEYFLEX 1405 is one of our most honored products in expansion joint materials with a thickness of 1.14mm. This product consist of fiberglass typically a 42% resin content. When two films of PTFE are laminated to a fiberglass fabric layer, thus the films receive the foundation that it must have to survive in the expansion joint sealing service.
2. KEYFLEX 1405 is a composition of designed fiberglass and PTFE layer. This material is suitable for flexible expansion joint application.
3. KEYFLEX 1405 is extremely thin and flexible. But its distinguish thickness and flexibility does not change the properties of our high quality products.

Advantages:

  • Successfully used in expansion joint service for almost 20 years
  • Proven coating and lamination technology for industrial fabrication
  • Excellent mechanical behavior
  • Ease of use & packing
  • Excellent chemical resistance
  • Less thickness than KEYFLEX 14-7
  • Higher PTFE content than KEYFLEX 14-7
  • Similar mechanical behavior as KEYFLEX 14-7
Teflon Layer

Description

1. Teflon layer is an exceptionally thin, high strength, PTFE laminate with a thickness of 0.13mm.
2. KeyFlex LFP 2105 is targeted for challenging thermo and chemical applications, this layer shows excellent gas seal behavior in flue duct expansion joints.
3. KeyFlex LFP 2105 consists solely PTFE, which means the material is, essentially, chemically inert. The product can operate in temperatures higher than 300°C. The non-porous membranes can be readily fabricated using a variety of heat sealing techniques. KeyFlex LFP 2105 is available in variety of colors and in a conductive or non-conductive construction.

* We have a wide range of thickness, specifications & colors available.Please check with us for more details.

Thermalam 50/1406

Description

1. This product is a high temperature expansion joint material designed for applications requiring an upper use continuous temperature of 1000°C (538°C). A half non-woven insulation material is laminated to KEYFLEX 1406.
2. The laminated insulation component acquires strength and resiliency from the load bearing per-fluoroplastic composite. The added integrity extends the life of the insulation and helps to prevent hot spots from forming on the belt.
3. Installation also becomes easier with a laminated insulation component. This product can be fabricated into numerous expansion components. This product can be fabricated into numerous expansion joint shapes and sizes.

KEYFLEX Texcoat 5 PTFE Coated Fiberglass

Description

1. KEYFLEX is one of our most honored products in expansion joint materials. This product consist of fiberglass typically a 35% to 45% resin content. When a film is laminated to a KEYFLEX product, the film receives the foundation that it must have to survive in the flue duct seal service.
2. KEYFLEX material 5 PRIMARY/STANDARD is a composition of designed fiberglass and PTFE layer. This material is suitable for flexible expansion joint application.
3. KEYFLEX material 5 PRIMARY/STANDARD is extremely thin and flexible. But its distinguish thickness and flexibility does not change the property of our high quality products.

Wire Inserted Glass Fabric Layer

Description

1. SS Wire Insert Glass textile is manufactured from fiberglass yarn capable of resisting heat up to 450¡.
2. This layer provides the advantages of asbestos products without the risk of use.
3. It is also stronger than general glass fiber fabric (UTS>1000MPa) due to the inserted SS Wire.
4. It will not burn, smolder, shrink and mildew.
5. At high temperature, this material shows chemical resistant and dielectric strength properties.

Silica Fabrics

Description

1. This is designed to provide protection from extreme heat and molten materials.
2. It has excellent thermal insulation characteristics and it is capable of withstanding temperatures of up to 3000°F.
3. Used for Personnel & Equipment Protection, Stress-relief blankets, fire & furnace curtains and heat shield applications for marine, industrial and aerospace industries.

Advantages:

  • High Chemical resistance
  • Additional treatments available to enhance performance as well as flexibility
  • Can be specified with other coatings to meet specific performance requirements
  • Minimum 96% silicon dioxide content
  • Available in ropes, fabrics, sleeving, tape, mat, and yarn
  • High resistance to most corrosive fluids
  • Does not generate any furnes/smoke even under extreme heat conditions
Glass Fabric Layer

Description

1. Glass Fabric Layer is manufactured from fiberglass yarn capable of resisting heat up to 450°C.
2. This layer provides the advantages of asbestos product without the risk of use.
3. It is a soft, flexible cloth. It features excellent draping qualities, and is ideal for industrial protective curtains and blankets etc. This finish may contain a small amount of processing strach, which burns off at around 240°C.
4. At high temperature, this material shows chemical resistant and dielectric strength properties.

Ceramic Fiber Blanket

Description

1. Ceramic Fiber Blanket is a low iron, high purity ceramic fiber blanket developed especially for use of in highly reducing atmospheres.
2. It is light weight, flexible and suitable for operating temperature up to 1260° (In our design, this minimum working is far higher than the design temperature). It is a highly efficient insulator having low heat storage capability and complete resistance to damage from thermal shock.
3. It has excellent resistance to oxidation and reduction and can withstand most corrosive agents, except hydrofluoric and phisphoric acid.
4. It has excellent strength, both hot and cold. If wet, steam or oil, thermal and physical properties remain unaffected after drying, it sound absorption ability is greater than than dense or insulation refectories and it stores some 90% less heat then dense fiber brick and about 78% less than insulation brick.

Advantages:

  • Low thermal conductivity
  • Excellent thermal stability (Much higher than that of the Glass Fabric)
  • Low heat storage
  • Resistance to thermal shock
  • Excellent corrosion resistance
Pyrogels

Description

1. Pyrogel® XT is a high-temperature insulation formed of silica aerogel reinforced with a non-woven, glass-fiber batting.
2. Pyrogels achieves excellent thermal performance in a flexible, environmentally safe, and easy-to-use product and is strongly recommended for the use of insulating piping, vessels, tanks, and equipment.

Advantages:

  • Excellent thermal performance
  • Ease of use & packing
  • Reduced thickness
  • Escellent fire protection
  • Environmentally-friendly
Glass Fabric Felt

Description

1. Glass Fabric Felt is a mechanically bonded glass fiber insulating felt in grade of 0.5 (12.5mm) for application up to 600°C.
2. It is manufactured entirely in long textile glass fiber and conditions on binders, thereby assuring insulation efficiency during extended exposure of temperature.

Advantages:

  • Non-combustible
  • For thermal insulation
  • Provide mechanical shock resistance
  • Sound absorption properties
  • Non-contribute to metal corrosion
Stainless Steel Wire Mesh

Description

1. Stainless Steel Wire Mesh is a high hardness, flexible, woven layer mainly used for provide extra mechanical support.
2. Conventionally, Stainless Steel Wire Mesh is placed on one or two sides of a thermal isolation blanket for use on vessels and pipes in refineries, power plants and refrigerated warehouses. This group of stainless steel wire woven also called metal mesh blanket material.
3. In our design, in order to provide extra safety and improve mechanical behavior of joint, this wire mes layer is added between ceramic fiber blanket and glass fabric felt.

Heat Sealer Equipment

Keyser Manufactures high-performance PTFE materials for industrial application. These materials often require thermal welding (heat sealing) in field service. Cost effective and easy-to-use heatsealers are provided by Keyser for use with Keyser materials.

Equipment Description
The main function of a heat sealer is to introduce enough heat to allow a proper bond between PTFE surfaces of Keyser material. The melting point of PTFE is more than 300°C. However, the setting of a heat scaling iron is determined by factors like ambient temperature, thickness of bonding materials, and the surface upon which you heat seal.

Applying pressure can help facilitate a good bond, but in order to achieve a correct bond, the melting point of the Keyser materials must be reached.

 

PFA

A Perfluoroalkoxy, Teflon-PFA adhesive is recommended for best sealing performance with Keyser materials. Place the PFA between the two surface to be sealed. For difficult angles, it may be easier to tack or staple the PFA in place. PFA thickness of 0.127mm (0.005) or 0.255mm (0.010) are typically used.

PFA Property
PFA is a type of fluoropolymer with properties similar to polytetrafluoroethylene (PTFE)

Heat Sealer Process
Step 1

Prepare a surface that will not CONDUCT AWAY the heat. The thermo insulation material shown in the above picture is ideal for this purpose.

Step 2

A Keyser adhesive thin film is recommended for best sealing performance with Keyser materials. Place the adhesive layer between the two surface to be sealed. For difficult angles, it may be easier to tack or staple the Keyser adhesive layer in place. Keyser adhesive layer thickness of 0.127mm or 0.255mm is typically used.

Step 3

Bring the heat sealer in contact with the splice area. Make sure the heat sealer has reached the set point temperature around 380°C before using.

Step 4

Applying pressure will achieve a better bond in a shorter time period. Resirence time for a heat seal is a function of the material and the ambient conditions. Around five minutes will typically work for standard products in a normal plant setting. For wide splices or special geometry shapes, heat seal in sections, allowing a slight overlap from one section to the next to ensure a continuous bond.

Step 5

When the heat seal has been completed, remove the sealer. Allow the spice to cool to room temperature before handling.

Accessories

1. Teflon Coated Fiberglass Sewing Thread

a. This is a machine sewing thread with a left-hand twist made from 100% fiberglass yarns coated with Teflon.
b. Available in other diameters other than the standard 0.021.
c. High tensile strength of 25.

2. KEY SEAL (Joint Sealant & Gasket Tape)

KEY SEAL is a 100% Virgin PTFE production. KEY SEAL Joint Sealant and Gasket Tape is a widely tested and proven way to seal liquids and gases of any kind in wet or dry service.

This highly fibrillated expanded PTFE exhibits flexibility, compressibility, stability under high temperatures, and high-tensile strength. The chemically inert product resists creep relaxation and maintains a seal even at extreme temperatures.

KEY SEAL Joint Sealant is ideal for worn flanges of all sizes. KEY SEAL Gasket Tape is a flat sealant designed for surfaces requiring a strip or full-face gasket.

Ease Of Use

Use scissors to cut to the desired length. The adhesive holds the sealant in place while positioning around the flange inside the bolt circle to isolate the flow media. The nonstick properties of PTFE allow the flanges to separate freely. The recommended size is about 40%-50% of the sealing surface. Remove the backing of the adhesive and loop it around the inside of the bolt circle, then overlap the ends of the joint sealant about 3/4 — 1 on either side of a bolt hole.

KEY SEAL Advantages:

  • 100% Virgin PTFE
  • Resistant to Cold Flow Compressibility
  • Easy to Install / Remove
  • Stable at High Temperatures
  • No Decay with Age
  • No Flow Contamination
  • Non-Toxic
  • Non-Flammable
  • Never Fray
  • FDA Suitable (Biological inert at Room Temperature)

Standard sizes being used in different industries:

Key Duct

A flexible ducting product line engineered for high temperature & chemical usage.

A PTFE flexible duct has the following advantages:

  • Superior chemical resistance, thermal stability and mechanical strength
  • Durable & impervious interior
  • Exterior LFP corrosion barriers are available in different thickness
  • Other special and unique features
  • Contains a strong laminated seal that encapsulates a rugged spring coil and joins the two LFP corrosion barriers

We have a wide range of sizes for different applications. Please check with us for more details.

Flex Test For KEY DUCT

Benefits

  • Lightweight
  • Positive and negative pressure capability
  • Excellent non flammability properties
  • Excellent chemical resistance
  • Wide temperature range -100…F To 500…F (-73…C To 260…C)
  • Wide range of duct diameters and lengths
  • Many Special Features:

– Flanges
– Colors
– Conductivity
– Cuffs
– Wear strip / for abrasion resistance
– Etc.