Applications involving aggressive media, such as strong acids and basic chemicals, present the challenge of finding the optimal gasket material. Depending upon the particular media being processed, and the operating conditions, choosing the right gaskets for aggressive media applications may be either a straightforward or complex task.
It is important to note that the resistance of any given gasket material to degradation or corrosion is influenced by multiple factors. For example, applications which involve the use of highly concentrated acids will affect gasket performance differently than applications which involve the same acid at a lower concentration. Similarly, applications using media of high purity may degrade gasket materials at a more accelerated rate than applications where impurities are present in the same media.
Then, too, there is the issue of mechanical loading to consider. Gaskets are mechanical systems whose performance can be affected by the load imposed by the forces exerted by joint fastening and compression. Complicating this issue is the fact that the specific operating conditions into which a gasket is placed can also greatly influence the compressive force applied onto the gasket by bolting.
While the majority of gasket failures are caused by lack of load, some aggressive media applications involve low load conditions. For these applications, restructured PTFE gaskets, such as those made from Tealon™ PTFE sheet from Teadit North America, may be the material of choice.
In food grade applications, users have the additional challenge of ensuring that any gasket material they select complies with all applicable regulations.
The table below shows the resistance level of various gasket materials to some common aggressive media. Gasket materials shown include the following:
NBR – Nitrile rubber
EPDM – Ethylene propylene diene rubber
FKM – Fluoroelastomer
FFKM – Perfluoroelastomer
CR – Chloroprene (Neoprene®) rubber
PTFE – Polytetrafluorethylene rubber
Material resistance levels are shown as follows:
U – Unsuitable; material will exhibit significant degradation.
LS – Limited suitability: material will exhibit some degradation, dependent upon specific operating conditions.
S – Suitable; material is unaffected.
We emphasize that this abbreviated table should be used only as a general guide and that users should contact us directly for more precise guidance on the preferred material to use for their specific application
Canada Rubber Group Inc. can supply gaskets precision-cut from materials that can service aggressive media applications. We carry a full line of premium gasket materials, including those supplied by Teadit North America, and use the latest technology to produce our gaskets.
Please contact our sales department at crg@canadarubbergroup.com for further information on how we can help service your aggressive media application.