• Jul
  • 29
  • 2013

Leakage Rubber Bellow

Posted by Wadih In Uncategorized | Comments Off on Leakage Rubber Bellow


Leakage Rubber Bellow

Leakage Rubber Bellow

It is most important to determine where the leak originated prior to implementing any corrective action. If leakage or weeping is occurring from any surface of the expansion joint, except where flanges meet, replace the joint immediately. If leakage occurs between the mating flange and the expansion joint flange, tighten all bolts. If this is not successful, turn off the system pressure, loosen all flange bolts and then re-tighten bolts in stages by alternating around the flange. Make sure there are washers under the bolt heads, particularly at the split in the retaining rings. There should be no gap at the retaining ring split. Remove the expansion joint and inspect both rubber flanges and pipe mating flanges for damage and surface condition. Repair or replace as required. Also, make sure the expansion joint is not over elongated as this can tend to pull the joint flange away from the mating flange resulting in leakage. If leakage persists, consult SilverFox
Root causes include: Under torqued bolts, irregular sealing surface (optimal mating surface is full face flat flanges); over extension and chemical attack by the media.
Corrective action; tighten the bolts to the manufacturers torque recommendations. Change to proper design and chemically compatible material. Measure the face to face dimension prior to replacement.

  • Jul
  • 11
  • 2013

Rubber Bellow Fatigue

Posted by Wadih In Uncategorized | Comments Off on Rubber Bellow Fatigue


Blisters / Deformation / Ply Separation
Some blisters and deformation when on the external portions of an expansion joint may not adversely affect the performance of the expansion joint. These blisters or deformations are cosmetic in nature and do not require repair. If major blisters, deformations and/or ply separations or delaminations exist in the tube, the expansion joint should be replaced as soon as possible. The root cause of delamination is either over-torque bolts, chemical attack by the media, aged rubber or some other form of break in the inner tube layer. Corrective actions include replacing the aged rubber expansion joint and ensuring the correct material selection for the application.

  • Jul
  • 01
  • 2013

Rubber Bellow Fatigue

Posted by Wadih In Uncategorized | Comments Off on Rubber Bellow Fatigue

Rubber Bellow Cracking


Familar Signs of Rubber Bellow Fatigue.
Exterior surface cracking is most commonly the result of aging and or elevated temperature. As rubber ages, it becomes hard and brittle and loses inherent flexibility & resilence. Cracking or crazing may not be serious if only the outer cover is involved & the fabric is not exposed. If necessary, repair onsite with rubber cement where cracks are minor. Carefully inspect cracks to determine if underlying fabric reinforcing plies are compromised. Cracking where the fabric is exposed & torn, indicates the expansion joint should be replaced. Such cracking is usually the result of excess extension, angular or lateral movements. Such cracking is identified by (1) a flattening of the arch, (2) cracks at the base of the arch &/or (3) cracks at the base of the flange. Cracking at the base of the flange/arch is more to do with movement & misalignment. Corrective action, measure the face to afce and lateral alignment prior to ordering a replacement and install control units to maintain acceptable movement limits of the expasnion joint during operation

  • Jun
  • 24
  • 2013

Fabric Expansion Joint Units

Posted by Wadih In Uncategorized | Comments Off on Fabric Expansion Joint Units

Fabric Expansion Joint Unit Assembly

Expansion Joint Unit Assembly

Silverfox expansion joint units are delivered ready for installation in the ductwork.The flexible components and steel parts are pre-assembled ensuring fast and simpleinstallation. The expansion joint , insulation bolster and steel parts are designed  foroptimal duaability based exactly on the operational conditions in the part of the ductwork where the unit is installed.SilverFox has the engineering, design and manufacturing support and ability to provide any technical solution involving expansion joints.

  • Jun
  • 17
  • 2013

Pressure Balanced & Universal Expansion Joints

Posted by Wadih In Uncategorized | Comments Off on Pressure Balanced & Universal Expansion Joints

Metal Expansion Joints

Metal Expansion Joint

Silverfox can custom design and supply various types of expansion joints based on

your needs and requirements of the system. Some commonly used expansion joints are:

Universal Expansion Joint

Universal expansion joints are used where axial movement is larger than can be absorbed by a single

expansion joint. The universal expansion joint assembly consists of two single expansion bellows

connected by intermediate pipe. Universal expansion joints can also be used used where large amount

of movement in any combination (axial, lateral and angular rotation) is required which cannot be absorbed by a

single expansion joint.


Piping Expansion Joints

Pressure Balanced Expansion Joint

Elbow Pressure Balanced expansion joints are designed to absorb axial and /or lateral deflection

while continuously restraining the pressure force. Balance (out of line) bellows creates an equal

and opposite force to the working (in line) bellows The typical arrangement as shown is to have a

balance side and a working side separated by an elbowed mid-section. Tie rods are used to

balance and restrain pressure forces.


Additional Types of Expansion Joints available from SilverFox

  • Gimbal Expansion Joint
  • Hinge Expansion Joint
  • In-line Pressure Balance Expansion Joint
  • Externally Pressurized Expansion Joint
  • Pantograph Linkage Expansion Joint
  • Two-Ply Testable Expansion Joint
  • Jacketed Expansion Joint


  • Jun
  • 10
  • 2013

Rubber Expansion Joints and Connectors

Posted by Wadih In Uncategorized | Comments Off on Rubber Expansion Joints and Connectors



Arch Type:

A full face integral flange design is available in both Single Arch and Multiple Arch Types expansion joints. These basic types can be manufactured to meet requirements of ASTM F1123-87. These types of expansion joints are available in several construction design series, based on the application pressure requirements.

Single Narrow Arch Type.

Construction is of fabric and rubber, reinforced with metal rings or wire. The full face flanges are integral with the body of the expansion joint and drilled to conform to the bolt pattern of the companion metal/FRP flanges of the pipeline. This type of rubber expansion joint face flange is of sufficient thickness to form a tight seal against the metal/FRP flanges without the use of gaskets. The shortest rubber expansion joint face to face dimensions are available with this type of rubber expansion joint construction.

  • Jun
  • 02
  • 2013

Metal Expansion Joints – Types of End Conections

Posted by Wadih In Uncategorized | Comments Off on Metal Expansion Joints – Types of End Conections


There are various end connections for Metal Expansion Joints to suit your application.These types of metal expansion joint end connections are:

Flanges – including special flanges, slip on or angle flanges to suit any standatd or non standard drill pattern.

Metal Bellows

Vanstone Ends – are modofied flanged ends with the added flexibility in resolving bolt-hole misalignment.

Metal Bellow Vanstone Ends

Weld Ends – allows any pipe or duct to be attached to a expansion joint for welding into a pipe system.

Metal Bellow Weld Ends

  • May
  • 28
  • 2013

Rubber Expansion Joints Applications

Posted by Wadih In Uncategorized | Comments Off on Rubber Expansion Joints Applications

Rubber12Rubber expansion joints provide time-tested ways to accommodate pressure loads, relieve movement stresses, reduce noise, isolate vibration, compensate for misalignment after plants go on stream and prolong life of motive equipment. Rubber expansion joints, designed by engineers and fabricated by skilled  craftsmen, are used in all systems conveying fluids under pressure and/or vacuum at various temperatures.


  • Air Conditioning, heating and ventilating systems in commercial, and institutional buildings, schools, apartments, stores, hospitals, motels, hotels and ships.
  • Central and ancillary power-generating stations in communities, factories, buildings and aboard ships.
  • Sewerage disposal and water treatment plants.
  • Process piping in paper & pulp, chemical, primary metal and petroleum refining plants.


Careful selection of the expansion joint design and material for a given application, as well as properly engineered installation are important factors in determining performance. These factors should be fully evaluated by every person selecting and applying expansion joints for any application.

  • May
  • 17
  • 2013

Fabric Expansion Joint Applications

Posted by Wadih In Uncategorized | Comments Off on Fabric Expansion Joint Applications


Fabric Expansion Joint Applications. Fabric Expansion Joints are used to take up vibration and thermal expansion in air & flue gas duct systems.
As a guide, all applications can be divided into general categories based on media composition (Air or Gas), temperature and pressure.

Expansion Joints

Clean Air Systems (-40 to +200c) (+/-50 kpa)
Single layer expansion joint material such as coated fabrics, plastics, fluoropolymers and fluoro elastomers with options to be reinforced with a fabric / polester fibre material. Suitable for heating and ventilation systems, fans and conveyors.

Air & Flue Gas Systems (-35 to +575c) (+/-50kpa)
Multi layers consisting of various densities and strengths of glass fabric and thermal glass insulation layer. A gas tight layer of PTFE foil with external layer of silicone coated fabric or alternatively with gas tight layer of reinforced PTFE laminate / coating. Construction arrangement is determine by temperature, pressure, medium and system movements. Suitable for Power Plants, Cement, Smelters and Refineries.

Hot Flue Gas Systems (-35 to + 1000c) (+/-50kpa)
Again multi layer construction ulitilisng robust high strength glass fabric layers with thermal glass insulation layer. To provide strength & stability and temperature resistance a layer of stainless steel wire mesh & bands is placed on the gas side. External protection with a layer of durable and strong PTFE based laminate. For very hot applications such as Smelters and Furnaces.

Depending on the application operating conditions the bolster can be made up from different material combinations: outers layers of various types of glass fabrics and stainless steel wire mesh and internal fillers of eiither or combination of loose glass insulation and glass felt layers. Bolsters provide protection to the fabric expansion joint from thermal temperature, dust particles and pulsations

  • May
  • 09
  • 2013

Gas Turbine Fabric Expansion Joints.

Posted by Wadih In Uncategorized | Comments Off on Gas Turbine Fabric Expansion Joints.


GTX Gas Turbine Fabric Expansion Joints are available in a variety of steel frame designs and fabric expansion joint materials. All standard fabric expansion joint designs can be modified to suit most customer requirements.

The new revolutionary fabric expansion joint design solutions introduced with the GTX-range of fabric expansion joints that have been achieved through several years of testing, involving intensive use of FEA-calculations (Finite Element Analysis). There are three standard fabric expansion joint designs available:

GTX-A: This fabric expansion joint is used in applications that have no pressure pulses and have fairly smooth flow velocities. The fabric expansion joint design is typically used on units installed down stream of the gas turbine, after the diffuser sections where the gas flow characteristics have smoothed.

GTX-B: This is the most commonly used fabric expansion joint design that will withstand normal pressure pulses and flow conditions. A unit composed of this fabric expansion joint design can be installed e.g. at the bypass outlet sections or after the diffuser sections.

GTX-C: This fabric expansion joint design is recommended for heavy-duty gas turbine exhaust applications where high pressure pulsations with turbulent flow conditions exist.

Based on the information provided by our customer, the choice of bellows type is generally suggested by SIlverfox.