What are the length, spacing and pattern required for metallic anchors in a refractory installation?

The typical refractory anchor has the tip of the longest leg of the anchor that is not greater than 1” (25mm) from the surface of the refractory lining. Some specifications require that other  leg of this anchor be ½” (13mm) shorter than the long leg of the anchor which would place the tip of this anchor 1 ½” (38mm) from the surface of the refractory lining.  These offset legs are used to prevent a separation plane at the tip of the refractory anchors from occurring during the dry out or operation of the unit.

Typical anchor spacing in a refractory lining will vary depending on the thickness and density of the refractory lining. Other than PIP, there are no stated industry standards spacing of anchors, there are established industry guidelines that can be followed to ensure that there are a sufficient number of anchors to support the monolithic lining.   There are several refractory material manufacturers who have issued guidelines for the use of anchors for their material however these are guidelines and not actual refractory designs.