ASTM C1774-13
Standard Guide for Thermal Performance Testing of Cryogenic Insulation Systems

Standard No.

ASTM C1774-13

Release Date

2013

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM C1774-13(2019)

Latest

ASTM C1774-13(2019)

Scope

5.1 A key aspect in understanding the thermal performance of cryogenic insulation systems is to perform tests under representative and reproducible conditions, simulating the way that the materials are actually put together and used in service. Therefore, a large temperature differential across the insulation and a residual gas environment at some specific pressure are usually required. Added to these requirements are the complexities of thickness measurement at test condition after thermal contraction, verification of surface contact and/or mechanical loading after cooldown, and measurement of high vacuum levels within the material. Accounting for the surface contact resistance can be a particular challenge, especially for rigid materials (32). The imposition of a large differential temperature in generally low density, high surface area materials means that the composition and states of the interstitial species can have drastic changes through the thickness of the system. Even for a single component system such as a sheet of predominately closed-cell foam, the composition of the system will often include air, moisture, and blowing agents at different concentrations and physical states and morphologies throughout the material. The system, as tested under a given set of WBT, CBT, and CVP conditions, includes all of these components (not only the foam material). The CVP can be imposed by design or can vary in response to the change in boundary temperatures as well as the surface effects of the insulation materials. In order for free molecular gas conduction to occur, the mean free path of the gas molecules must be larger than the spacing between the two heat transfer surfaces. The ratio of the mean free path to the distance between surfaces is the Knudsen number (see C740 for further discussion). A Knudsen number greater than 1.0 is termed the molecular flow condition while a Knudsen less than 0.01 is considered a continuum or viscous flow condition. Testing of cryogenic-vacuum insulation systems can cover a number of different intermediate or mixed mode heat transfer conditions.

5.2 Levels of thermal performance can be very high: heat flux values well below 0.5 W/m² are measured. This level of performance could, for example, correspond to a k_e below 0.05 mW/m-K (R-value = 2900 or higher) for the boundary temperatures of 300 K and 77 K and a thickness of 25 mm. At these very low rates of heat transmission, on the order of tens of milliwatts for an average size test apparatus, all details in approach, design, installation, and execution must be carefully considered to obtain a meaningful result. For example, lead wires for temperature sensors can be smaller diameter, longer length, and carefully installed for the lowest possible heat conduction to the cold mass. In the case of boiloff testing, the atmospheric pressure effects, the starting condition of the cryogen, and any vibration forces from surrounding facilities should also be considered. If an absolute test apparatus is to be devised, then the parasitic heat leaks shall be essentially eliminated by the integrated design of the apparatus and test methodology. The higher the level of performance (and usually the higher level of vacuum), the lower the total heat load and thus the parasitic portion shall be near zero. For a comparative apparatus, the parasitic heat leaks must be reduced to a level that is an acceptable fraction of the total heat load to be measured. And most importantly, for the comparat........

ASTM C1774-13 Referenced Document

• ASTM C1029 Standard Specification for Spray-Applied Rigid Cellular Polyurethane Thermal Insulation
• ASTM C1045 Standard Practice for Calculating Thermal Transmission Properties Under Steady-State Conditions
• ASTM C1058 Standard Practice for Selecting Temperatures for Evaluating and Reporting Thermal Properties of Thermal Insulation
• ASTM C1482 Standard Specification for Polyimide Flexible Cellular Thermal and Sound Absorbing Insulation
• ASTM C1484 Standard Specification for Vacuum Insulation Panels
• ASTM C1594 Standard Specification for Polyimide Rigid Cellular Thermal Insulation
• ASTM C1667 Standard Test Method for Using Heat Flow Meter Apparatus to Measure the Center-of-Panel Thermal Transmission Properties of Vacuum Insulation Panels
• ASTM C167 Standard Test Methods for Thickness and Density of Blanket or Batt Thermal Insulations
• ASTM C168 Standard Terminology Relating to Thermal Insulation
• ASTM C1728 Standard Specification for Flexible Aerogel Insulation
• ASTM C177 Standard Test Method for Steady-State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate Apparatus
• ASTM C335 Standard Test Method for Steady-State Heat Transfer Properties of Horizontal Pipe Insulation
• ASTM C518 Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus
• ASTM C520 Standard Test Methods for Density of Granular Loose Fill Insulations
• ASTM C534 Standard Specification for Preformed Flexible Elastomeric Cellular Thermal Insulation in Sheet and Tubular Form
• ASTM C549 Standard Specification for Perlite Loose Fill Insulation
• ASTM C552 Standard Specification for Cellular Glass Thermal Insulation
• ASTM C578 Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation
• ASTM C591 Standard Specification for Unfaced Preformed Rigid Cellular Polyurethane Thermal Insulation
• ASTM C680 Standard Practice for Determination of Heat Gain or Loss and the Surface Temperatures of Insulated Pipe and Equipment Systems by the Use of a Computer Program
• ASTM C740 Standard Practice for Evacuated Reflective Insulation In Cryogenic Service
• ASTM C870 Standard Practice for Conditioning of Thermal Insulating Materials
• ASTM E230 Standard Specification and Temperature-Electromotive Force (EMF) Tables for Standardized Thermocouples
• ASTM E408 Standard Test Methods for Total Normal Emittance of Surfaces Using Inspection-Meter Techniques
• ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• ISO 21014 Cryogenic vessels — Cryogenic insulation performance — Amendment 1

ASTM C1774-13 history

• 2019 ASTM C1774-13(2019) Standard Guide for Thermal Performance Testing of Cryogenic Insulation Systems
• 2013 ASTM C1774-13 Standard Guide for Thermal Performance Testing of Cryogenic Insulation Systems