Expansion Joints
- November 06, 2018
Gallagher Fluid Seals recently added the Rubber Expansion Joint Surveys & Failure Analysis white paper to our Resources page. This white paper discusses the importance of inspecting your plant’s expansion joints. Proper design and maintenance of rubber expansion joints plays a major role in the overall preservation and lifespan of a piping system.
It will also discuss failure analysis of rubber expansion joints and some of the leading causes of joint failure.
Below is an except from the white paper, discussing failure analysis of rubber expansion joints, and what it can tell you about the overall health of your piping system.
Failure Analysis
There are perceptible warning signs when an expansion joint is failing:
- Arch inversion indicating a system vacuum that has exceeded the joint’s specified expansion value.
- Cracking at the base of the arch, which indicates the joint has been over-elongated and should be replaced with one of the proper length.
- Ply separation on the outside of the cover. This is an indication the joint has been subjected to excessive movement.
- Leakage due to over-expansion, mating flange surface issues, or poor installation practices, especially (but not limited to) bolt tightness.
- Ballooning of arch, which indicates excessive system pressure.
- September 27, 2018
Gallagher Fluid Seals recently added the Rubber Expansion Joint Surveys & Failure Analysis white paper to our Resources page. This white paper discusses the importance of inspecting your plant's expansion joints. Proper design and maintenance of rubber expansion joints plays a major role in the overall preservation and lifespan of a piping system.
It will also discuss failure analysis of rubber expansion joints and some of the leading causes of joint failure.
Download your copy today, and contact our engineering department if you need assistance choosing the right expansion joints for your processes.
- September 28, 2017
In July, Gallagher released its Expansion Joint Design Guide, now available for download on our site. This design guide takes an in-depth look at elastomeric, metal, and flue duct expansion joints. The excerpt below is a section of our Expansion Joint Design Guide focusing on types of flue duct expansion joints. To download the entire guide, visit our Resources Page, or click on the image to the right.
Flue Duct Expansion Joints
Used to manage air and gas handling systems, flue duct expansion joints are most widely utilized in the Power Generation, Industrial & Institutional industries:
- August 24, 2017
Gallagher recently released its Expansion Joint Design Guide, now available for download on our site. This design guide takes an in-depth look at elastomeric, metal, and flue duct expansion joints. The excerpt below is a section of our Expansion Joint Design Guide focusing on types of metal expansion joints. To download the entire guide, visit our Resources Page, or click on the image to the right.
Much like elastomeric expansion joints, metal expansion joints are used to preserve the integrity of a piping system where the piping is subject to changes in temperature, pressure, vibration, compression, extension, cyclical movements or movements required by usage.
Oftentimes, metal expansion joints are used when an elastomeric joint simply cannot handle the extreme conditions - applications where high temperature, large temperature range, or high pressure exists. Generally, metal expansion joints can be used from -450°F to +2000°F, depending on the metallurgy, and can also handle pressures from full vacuum to 3,000psi.
Metal Expansion Joint Components
Though customized and intricate expansion joints can be manufactured for a variety of specialized applications, there are four basic designs that are most commonly used:
Basic Bellows
A bellows can be supplied without end fittings for field installation. The skirt, or straight portion at each end of the bellows, can be sized to fit a flange or pipe. Skirt length can vary depending on your needs and should be specified when ordered.
Unrestrained Single
An unrestrained single expansion joint is best used by piping systems which are equipped with proper guides and anchors to absorb axial, angular, and a small amount of lateral movement.
- August 08, 2017
Gallagher recently released its Expansion Joint Design Guide, now available for download on our site. This design guide takes an in-depth look at elastomeric, metal, and flue duct expansion joints. The excerpt below is a section of our Expansion Joint Design Guide focusing on types of elastomeric joint installation, pipe layouts, and joint troubleshooting. To download the entire guide, visit our Resources Page, or click on the image to the right.
Preparation
Check Service Range
- Double check expansion joint performance limits against anticipated operating conditions
- Check temperature, pressure, vacuum recommendations
- Check total joint deflection—alter as needed to reduce deflection to correct range
- Anchor lines
Check Location
- Proper location is usually close to main anchoring point
- Install pipe guide(s) for proper alignment
- Joint should absorb pipeline expansion / contraction between fixed anchor points
- July 25, 2017
Gallagher recently released its Expansion Joint Design Guide, now available for download on our site. This design guide takes an in-depth look at elastomeric, metal, and flue duct expansion joints. The excerpt below is a section of our Expansion Joint Design Guide focusing on types of elastomeric joints and types of pipe movement. To download the entire guide, visit our Resources Page, or click on the image to the right.
The basic purpose of an expansion joint is to absorb movement and vibration in a rigid piping system, being built to expand, contract, and adjust without straining or breaking the piping or ducting on either side. They are specially engineered to handle movements due to thermal expansion, vibrations of pumps, and misalignments due to installation tolerances, while also being resistant to the process conditions and the external influences of the application.
Types of Expansion Joints
- Fabric and rubber construction
- Reinforced with metal/wire rings
- Full-face flanges integral with joint body
- Flanges drilled to companion bolt pattern
- Gaskets not required
- Offset available
- June 29, 2017
An expansion joint can relieve stress in piping systems and prevent flange gaskets from being crushed. But which expansion joint is best for your specific application? Let us first describe the two types of expansion joints:
Rubber — a flexible connector fabricated of natural and/or synthetic elastomers and fabric and, if necessary, internal metallic reinforcements designed to provide stress relief in piping systems due to thermal movements and mechanical vibration.
Metal — a flexible element (bellows) constructed of relatively thin gauge material (generally stainless steel) designed to absorb mechanical and thermal movements expected in service.
Advantages: Metal Expansion Joints
Temperature
Rubber joints with standard construction and materials have an upper range to 230°F. Most manufacturers, however, can offer special constructions up to 400°F. Metal expansion joints do offer a far greater range, from -420°F to +1800°F. However, working pressures are reduced at elevated temperatures. - June 27, 2017
Gallagher recently released its Expansion Joint Design Guide, now available for download on our site. This design guide takes an in-depth look at elastomeric, metal, and flue duct expansion joints. The excerpt below is the first section of our Expansion Joint Design Guide, diving into elastomeric expansion joints, and what to consider when selecting which joint is right for your application. To download the entire guide, visit our Resources Page, or click on the image to the right.
What is an Expansion Joint?
An expansion joint is a specially engineered product inserted in a rigid piping system to achieve one or more of the following:
- Absorb movement
- Relieve system strain due to thermal change
- Reduce mechanical noise
- Compensate for misalignment
- Eliminate electrolysis between dissimilar metals (metal expansion joints)
They are built to expand, contract, and adjust without straining or breaking the piping or ducting on either side. Essentially, an expansion joint is meant to protect the piping system from damage.
- May 23, 2017
Much like elastomeric expansion joints, metal expansion joints are used to preserve the integrity of a piping system where the piping is subject to changes in temperature, pressure, vibration, compression, extension, cyclical movements or movements required by usage.
Oftentimes, metal expansion joints are used when an elastomeric joint simply cannot handle the extreme conditions - generally high temperature, large temperature range, or high pressure exists in your application. Generally, metal expansion joints can be used from -450°F to +2000°F, depending on the metallurgy, and can also handle pressures from full vacuum to 3,000psi.
- March 30, 2017
Gallagher Fluid Seals represents a number of expansion joint manufacturers, enabling us to provide an expansion joint for any piping system in any industry. The ABRA-LINE™ Rubber Expansion Joints from Garlock are meant for highly-abrasive applications.
The Garlock ABRA-LINE™ Style 4394 Rubber Expansion Joint is a multi-convoluted, lightweight expansion joint, designed for lower pressure applications that require significant amounts of movement, axially and/or laterally. Its low spring rates make it ideal for load cell, bin activator, vibrating bin, silo, and shaker boot applications. The below success story comes directly from Garlock and an application using the ABRA-LINE™ Style 4394 joints.