Active Standard: C740 / C740M - 97(2009)
A task group has been meeting since 2010 to revise this standard guide for evacuated reflective insulation [or multilayer insulation (MLI)] in cryogenic service. The document (draft #6) is a total revision of the current standard which has not been substantially modified since it was introduced in the 1970s. Now included are a wide range of representative data sets for heat flux (the current standard has only limited data for effective thermal conductivity). Application environments for high vacuum, soft vacuum, and non vacuum are also addressed. We are submitting this document (draft #9) for a full committee ballot. Comments have been incorporated and changes have been made, as shown, following full committee ballot 2/15/13 and input from the Spring 2013 meeting in Indianapolis. There was one negative comment and it was found to be persuasive. The correction was to term the standard a Guide rather than a Practice.
Keywordscryogenic insulation; insulation; multilayer insulation; radiation; radiation shields; reflective insulation; super insulation; vacuum insulation; Emittance; Blanket method; Blanket thermal insulation; Cryogenic service environments; Degradation--thermal insulation; Evacuated reflective insulation; Filament-wound materials; Foil; Installation--thermal insulating materials; Interstitial gas; Metallic foil insulation; Metallized plastics; Reflective insulation; Separator materials; Sheet materials (general); Shielding; Single-layer method; Spiral-wrap method; Temperature tests--thermal insulation;
Ballot Item Approved as C740-2013 and Pending Publication