Explore Insulation Materials: Molded Expanded Perlite

Molded Expanded Perlite Insulation Products

Molded expanded perlite insulation is defined by ASTM as an insulating material consisting primarily of expanded perlite and a silicate binder. It may also contain reinforcing fibers.

ASTM C610 covers perlite pipe and block insulation. The standard covers materials with operating temperatures between 80°F and 1200°F.

Perlite Pipe Insulation

Perlite pipe insulation is supplied as hollow cylinders in half or quarter sections, or curved sections. Pipe insulation sections are typically supplied in 36" lengths and are available in sizes to fit most standard pipes. Available thicknesses range from 1" to 4" in increments of ½".

Nested sections are available in thicker insulation.

Perlite block insulation is available in lengths of 36" and 1 meter, widths of 24", and thicknesses of 1½" to 6" in ½" increments. Perlite molded fitting overlay insulation is available for a variety of standard elbows and tees. Scored and V-groove sections are also available. Special shapes, such as valve or fitting insulation, can be made from standard sections.

Perlite usually comes with a metal or fabric jacket to protect appearance and weather.

The specified maximum thermal conductivity for block and pipe insulation at an average temperature of 100°F is 0.48

Btu-in/(h-ft²-°F).

Perlite insulation products also meet ASTM C610 requirements for flexural (bending) strength, compressive strength, tumbling weight loss, moisture content, linear shrinkage, water absorption after thermal aging, surface burning characteristics, and thermal surface properties. In addition, it meets the criteria for use in contact with austenitic stainless steel.

Typical applications include

Piping and equipment operating at temperatures above 250°F, storage tanks, vessels, heat exchangers, steam

piping, valve and fitting insulation, boilers, vents and exhausts. Perlite insulation is commonly used in insulation systems where water can enter and cause corrosion or process problems. Examples of this include flushing areas, flood testing, piping for temperature cycling, and stainless steel that is susceptible to stress corrosion cracking.