Evacuated Perlite Cryogenic Insulation Specifications

"Super" Insulating Perlite for Evacuated Cryogenic Service
Prepared by: The Perlite Institute

EVACUATED PERLITE CRYOGENIC INSULATION SPECIFICATIONS
Density:	8 to 9.5 lb./ft3 (128 to 152 kg/m3)
Sieve Analysis (mesh is U.S. Standard)	Max. 5% +30 mesh (0.6 mm)*
Thermal Conductivity**	0.0047 Btu.in/h.ft2. F (0.0007 W/m.K)
* Tests have shown that the finer the material the better its preformance (Within the specified range). ** Thermal conductivity depends on temperature, density, and sieve analysis of expanded perlite and the interstitial pressure. + At -160 F (-107 C), 8.7 lb/ft3 (139 kg/m3), 0.01u (1.33 mPa)