Are Your Expansion Joints Failing? Find Out the Reasons Why

Movements in piping systems are inevitable, which can be caused by either thermal growth, equipment movement, vibration, or pressure pulsation. To balance out movement while containing pressure and the medium running through it, an expansion joint is used. 

But, sometimes, the expansion joint may fail, and there are various reasons behind this, which this discussion will tackle:

– Bellow joint expansion failure

– Expansion joint fatigue

– Rupture or squirm

– Inadequate testing

– Improper usage

5 Reasons Why Expansion Joints Fail 

Bellow Material Failure

If there’s one flexible element within an expansion joint, that has to be the bellows component. This flexibility is necessary to absorb expansion or vibration. Bellow joint expansion material failure results from stress corrosion cracking due to contact with chlorides, and this is also true with nickel and stainless steel alloys. Such allows have sulfuric acids or sulfides in their composition. The moment the bellows suffer from cracks, it is only a matter of time before failure occurs.

Expansion Joint Fatigue

The next reason for the failure of expansion joints is expansion joint fatigue. This refers to the too much vibration or high cyclic application that causes constant movement on the bellows. This constant movement causes the bellows to wear out. 

Rupture or Squirm

The third reason is squirm or rupture. Once the system containing your expansion joint has been overly pressurized, either of those two instances occurs. Squirming pertains to a condition wherein the bellows ends are still on the same center line, but they deflect by themselves upon reaching a critical pressure. Rupture is when the expansion joint material has been breached, also causing failure over just a short amount of time. 

Insufficient Testing

Inadequate testing is among the most common mistakes people commit when having their expansion joints. Failure to properly test these joints while in place, or when they have not been installed appropriately, failure in operation ensues, even under minimal stress.

Improper Use

Also, there are times when expansion joints are installed in applications outside or beyond the tolerable limits of their intended use. For example, such joints may be installed in scenarios or situations where pipe misalignment is excessive, or when your expansion joint has been installed successfully, but the orientation is incorrect. 

Likewise, some people make the mistake of installing expansion joints with insufficient supports. So, they must be securely anchored in such a way that the movement is allowed in the direction originally planned for, as they were designed to, and they must also adequately have the forces developed from the effects of interior pressure. 

Moreover, expansion joints failing may also be due to the installation of these joints that exceed design specs, such as:

• Too much pressure
• Excessive movement or vibration
• Extreme temperature
• Unexpected vacuum

Ways to Avoid Failure of Expansion Joints

Follow these tips to avoid the failure of expansion joints, and prevent the causes before they can even come forward:

• Proper material selection: Choose durable and weather-resistant materials to prevent premature wearing and tearing.
• Regulation inspections: The secret is to conduct routine checks to avoid the issues.
• Correct installation: Follow the manufacturer’s guidelines to guarantee proper joint placement and functionality.
• Adequate movement allowance: Expansion joints must be able to accommodate thermal expansion and contraction.
• Appropriate sealing: To prevent water ingress and the accumulation of debris, apply high-quality sealants.
• Load management: Excessive loads can cause overstress and damage upon those joints.
• Timely repairs: Aside from routine checks, don’t hesitate to carry out repairs when you spot issues.

Conclusion

So, what is an expansion joint? These are materials installed in piping systems to balance out movement and contain pressure, as well as the medium passing through them. However, it is a hardline rule for these joints to fail. The reasons are plenty, from rupture to improper use. 

Instead of doing endless repairs, why don’t you invest in new, high-performing expansion joints, such as the lined expansion joints of YOUFUMI. Many of our expansion joints are equipped with high-density and high-permeation resistance properties, suitable for various lining methods. For a complete list of our catalog and to get to know more about our products, contact us today.

Reference

Reasons Why Your Expansion Joints are Failing (1)

Expansion Joints (2)