October Tip of the Month

Refractory Anchor Selection

One sometimes overlooked component of a refractory lining can be the anchoring system. Refractory materials require anchors to provide structural support to keep them in place throughout the useful life of the refractory lining.

Identifying the right anchoring system can often seem overwhelming because so many factors can come into play including the thickness and the density of the materials being supported, the process and the process temperature, and the location (overhead or sidewall) all play a roll.  On top of these factors there is no shortage of option when it comes to anchor types including wire, rod, cast, and ceramic.  Below we offer a few rules of thumb that may prove helpful when evaluating the proper anchoring system to employ during your next refractory maintenance project.

1. Wire anchors
   1. Wire anchors are typically used for linings less than nine (9) inches in total thickness although they can be used for thicker linings.
   2. Wire anchors come in many shapes and materials. The material to use is largely determined by the process temperature.  The most common materials are T304 and T310 stainless steel.
   3. It is important to properly fasten wire anchors to the steel structure that they are associated with. They should be installed per the proper welding details by a qualified installer.
2. Ceramic anchors
   1. Ceramic anchors are typically used for linings that are greater than nine (9) inches in thickness and where higher operating temperatures are present.
   2. Ceramic anchors can be fastened using multiple clips and can be welded to a shell or suspended from a structural steel grid.
   3. Ceramic anchors also can allow for additional movement when expansion, vibration, and other movement are a potential concern.
3. Other
   1. The anchors described above are typically associated with monolithic linings. There are other anchor types associated with other material types including pins for ceramic fiber, mesh products for thin applications of material, and more…
   2. Since the anchoring materials and the materials that they support expand differently it may be necessary to accommodate this expansion. This is often accomplished using plastic tips or mastic coatings.
4. Spacing and orientation
   1. It is critical to pay attention to spacing and orientation when installing refractory anchors. These characteristics can impact cracking prominence and pattern as well as the long-term effectiveness of the lining.

Selecting the proper anchor for the application can be a challenge.  If you would benefit from additional insight on the advantages and disadvantages associated with various anchoring systems reach out to Schad today we have experience selling, recommending, and installing nearly every kind of refractory anchoring system available.