Whether it’s an undetectable and slow process, or just a sudden and drastic failure, leaking flanges can cause severe problems for operators and engineers.
Here we take a look at the 3 most common reasons for industrial flange joints failing, and what you can do to ensure maximum integrity throughout the joint’s life.
Reason 1 – The fastener fails
Fasteners that aren’t tight enough provide the most amount of industrial failures. Whether they haven’t been made tight enough due to incorrect assembly, fastener failure, or simply self-loosening over time, fasteners can become a problem at any time.
Likewise, fasteners that are too tight can cause similar problems. Excessive load may mean crushing the gasket or increasing fatigue on an already ageing asset. Bringing stress corrosion cracking into any industry with integral pipeline is not a great idea.
Reason 2 – The gasket fails
A gasket failing could be down to several factors, including mechanically and manually.
Whilst mechanical deterioration over time and a gasket operating outside its original envelope will damage the structure over time, if installed correctly the gasket should not fail.
Manual problems, can however, cause problems both in the short and long term. Choosing the wrong gasket for the wrong application, with the wrong thickness for example can lead to problems right from installation. Damage handling or storing a gasket can also affect its efficiency.
Reason 3 – The flange fails
Whilst warped flanges may be the result of a mechanical problem, most problems occur as a result of a man made error again.
Flange surfaces damaged as a result of transportation and installation can lead to poor performance and potentially corrosion in the future.
Minimising joint failure
Every flange and potential problems it may suffer in the future are completely unique. It would be impossible to offer advice that resolve every businesses’ problems, however here are a few tips to minimise joint failure as published by European Sealing:
Use compatible components
Some would say this is a straightforward tip, but the majority of joint failure down to the wrong application or incorrect use of materials is alarming.
Make sure you’re using the correct machinery and materials with additional safety margins in case the application conditions move outside the envelope.
Follow storage and inspection recommendations
Are you following the correct storage and handling recommendations as stated by your expert suppliers? As we highlighted above, this is a particular concern with gaskets.
Cleaning and visual inspections should also be adhered to, making sure joints and all components are free of foreign material that may hinder performance during installation.
Implement corrosion techniques
Keeping the flange area dry is not the easiest task, but drainage holes go a long way to easing long term corrosion. The introduction of corrosion-resistant material on fasteners are also a good idea.
For stress corrosion cracking, all metallic fasteners are susceptible to SSC but problems can be minimised with heat treatment. The addition of a suitable coating like aluminium or graphite can on fasteners can also be a help.
It’s hard to put a time on when fatigue will get the better of your flange joint, but generally the higher the load, the faster fatigue will set in.
In this case it’s important to achieve the correct preload in the fasteners to not over or under exert pressure on your flange. Replacing fasteners periodically can ensure integrity is maintained for as long as possible.
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