Patent ID: 7259118

Claim:
A method of insulating an article in applications requiring resistance against repeated exposure to temperatures between 900° C. and 1100° C., comprising: disposing on, in, near or around the article thermal insulation which is a refractory insulating material comprising vitreous fibers having a composition comprising SiO 2 , CaO, MgO, and optionally Al 2 O 3 , wherein: (a) SiO 2 is present in an amount (1) greater than 58% by weight SiO 2 , if the amount of MgO in the composition is in the range 0 through 10 percent by weight; or (2) greater than the sum of (58+0.5 (weight percent of MgO−10)) percent by weight SiO 2 , if the amount of MgO in the composition is greater than 10 percent by weight; (b) an amount up to 42 percent by weight CaO; (c) an amount up to 31.33 percent by weight MgO., and (d) 0 to less than 3.97 percent by weight Al 2 O O 3 ; wherein; the refractory insulation material has a shrinkage of less than 3.5 percent when exposed to a temperature of 1000° C. for 24 hours, and has a shrinkage of less than 3.5 percent when exposed to a temperature of 800° C. for 24 hours; and wherein the refractory insulation material is essentially free of alkali metal oxide and boron oxide fluxing components.