General Cryogenic Standards
General Cryogenic Standards covers the safe design and operation of cyrogenic enclosures as well as going into air quality and insulation. Having a safe design as well as properly managing the air quality is essential to have a safe environment. These general standards for cryogenic standards can provide guidelines to safely operate a cryogenic operation.
CGA P-8.8-2021
Safe Design and Operation of Cryogenic Enclosures - 3rd Edition
Cryogenic enclosures can create potential process safety hazards. This publication identifies general hazards and provides guidance to reduce their frequency and consequences. It provides safety guidance and addresses design and operating practices only as they affect safety. This publication addresses both cryogenic air separation unit (ASU) and hydrogen/carbon monoxide (HYCO) processes. This publication is primarily to document current practices and is intended to apply to new facilities. It is recognized that some existing plants may not meet all recommendations or requirements from this publication. This publication need not be applied retroactively, including where this publication uses the word “shall”. This publication does not cover the following: generally accepted engineering practices for structures and process equipment; only those issues that are specific to cryogenic enclosures are included; enclosures for processes producing liquid hydrogen or helium. The extreme cold temperatures of these processes require specialized knowledge and practices that are beyond the scope of this publication; and, external structures on/attached to the cryogenic enclosure, for example, platforms, ladders, vents, lightning arrestors, etc. For more information on the safe location of oxygen and nitrogen vents relative to the location of platforms and ladders, see CGA P-8.7, Safe Location of Oxygen and Inert Gas Vents.
CGA P-8-2020
Guideline for Safe Practices for Cryogenic Air Separation Plants - 6th Edition
This publication serves the interest of those associated or concerned with air separation plant operations and applies to safety in the design, location, construction, installation, operation, and maintenance of cryogenic air separation plants. Emphasis is placed on equipment and operational and maintenance features that are specific to cryogenic air separation processes. Limited coverage is given to plant equipment such as air compressors, which are used in other industrial applications and for which safe practices in design, installation, and use have already been established elsewhere. Further, as this publication is not intended as a universal safe practice manual for specific design and safety features, it is also important to refer to the operating manuals of the equipment suppliers
ISO 14965:2000
Air quality - Determination of total non-methane organic compounds - Cryogenic preconcentration and direct flame ionization detection method
This International Standard describes a procedure for sampling and determining concentrations of total nonmethane volatile organic compounds (NMVOC) in the ambient atmosphere.
This International Standard describes the collection of cumulative samples in passivated stainless steel canisters and subsequent laboratory analysis. It describes a procedure for sampling in canisters at final pressures above atmospheric pressure (referred to as pressurized sampling). It employs a cryogenic trapping procedure for concentration of the NMVOC prior to analysis.
This International Standard describes the determination of the NMVOC by simple flame ionization detection (FID), without the gas chromatographic columns and complex procedures necessary for species separation.
This International Standard is applicable to carbon concentrations in the range from 20 ppbC to 10000 ppbC. See 12.4 for procedures for lowering the range.
Several variations to the method described in this International Standard are also possible; see clause 12.
ASME PTC 47.1-2017
Cryogenic Air Separation Unit of an Integrated Gasification Combined Cycle Power Plant
The object of this Code is to provide uniform test methods and procedures for conducting performance tests of air separation units (ASUs) supplying products to a gasification block and/or power block within an integrated gasification combined cycle (IGCC) facility. This Code provides test procedures that can yield results giving the highest level of accuracy consistent with engineering knowledge and practice.
ASTM C740/C740M-13(2019)
Standard Guide for Evacuated Reflective Insulation In Cryogenic Service
1.1 This guide covers the use of thermal insulations formed by a number of thermal radiation shields positioned perpendicular to the direction of heat flow. These radiation shields consist of alternate layers of a low-emittance metal and an insulating layer combined such that metal-to-metal contact in the heat flow direction is avoided and direct heat conduction is minimized. These are commonly referred to as multilayer insulations (MLI) or super insulations (SI) by the industry. The technology of evacuated reflective insulation in cryogenic service, or MLI, first came about in the 1950s and 1960s primarily driven by the need to liquefy, store, and transport large quantities of liquid hydrogen and liquid helium. ( 1- 6 ) 2 1.2 The practice guide covers the use of these MLI systems where the warm boundary temperatures are below approximately 400 K. Cold boundary temperatures typically range from 4 K to 100 K, but any temperature below ambient is applicable. 1.3 Insulation systems of this construction are used when heat flux values well below 10 W/m 2 are needed for an evacuated design. Heat flux values approaching 0.1 W/m 2 are also achievable. For comparison among different systems, as well as for space and weight considerations, the effective thermal conductivity of the system can be calculated for a specific total thickness. Effective thermal conductivities of less than 1 mW/m-K [0.007 Btu in/h ft 2 F or R-value 143] are typical and values on the order of 0.01 mW/m-K have been achieved [0.00007 Btu in/h ft 2 F or R-value 14 300]. ( 7 ) Thermal performance can also be described in terms of the effective emittance of the system, or e . 1.4 These systems are typically used in a high vacuum environment (evacuated), but soft vacuum or no vacuum environments are also applicable. ( 8 ) A welded metal vacuum-jacketed (VJ) enclosure is often used to provide the vacuum environment. 1.5 The range of residual gas pressures is from 10 -6 torr to 10 +3 torr (from 1.33 -4 Pa to 133 kPa) with or without different purge gases as required. Corresponding to the applications in cryogenic systems, three sub-ranges of vacuum are also defined: from 10 -6 torr to 10 -3 torr (from 1.333 -4 Pa to 0.133 Pa) [high vacuum/free molecular regime], from 10 -2 torr to 10 torr (from 1.33 Pa to 1333 Pa) [soft vacuum, transition regime], from 100 torr to 1000 torr (from 13.3 kPato 133 kPa) [no vacuum, continuum regime]. ( 9 ) 1.6 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific safety hazards, see Section 9 . 1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
SAE ARP 900C-2019
Methods for Evaluating Cryogenic Filters
The purpose of this document is to present test methods that can be utilized to evaluate the filtration and operating characteristics of filters that will be utilized in a cryogenic system. The methods presented herein are intended to supplement standard filter testing specifications to allow evaluation of filter performance characteristics in areas that could be affected by extreme low temperatures.
ASTM D5953M-16
Standard Test Method for Determination of Non-methane Organic Compounds (NMOC) in Ambient Air Using Cryogenic Preconcentration and Direct Flame Ionization Detection
1.1 This test method2 presents a procedure for sampling and determination of non-methane organic compounds (NMOC) in ambient, indoor, or workplace atmospheres.
1.2 This test method describes the collection of integrated whole air samples in silanized or other passivated stainless steel canisters, and their subsequent laboratory analysis.
1.3 This test method employs a cryogenic trapping procedure for concentration of the NMOC prior to analysis.
1.4 This test method describes the determination of the NMOC by the flame ionization detection (FID), without the use of gas chromatographic columns and other procedures necessary for species separation.
1.5 The range of this test method is from 20 to 10 000
ppb C (1, 2).3
1.6 This test method has a larger uncertainty for some halogenated or oxygenated hydrocarbons than for simple hydrocarbons or aromatic compounds. This is especially true if there are high concentrations of chlorocarbons or chlorofluorocarbons present.
1.7 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.
1.8 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
ASTM C1774-13(2019)
Standard Guide for Thermal Performance Testing of Cryogenic Insulation Systems
1.1 This guide provides information for the laboratory measurement of the steady-state thermal transmission properties and heat flux of thermal insulation systems under cryogenic conditions. Thermal insulation systems may be composed of one or more materials that may be homogeneous or non-homogeneous; flat, cylindrical, or spherical; at boundary conditions from near absolute zero or 4 K up to 400 K; and in environments from high vacuum to an ambient pressure of air or residual gas. The testing approaches presented as part of this guide are distinct from, and yet complementary to, other ASTM thermal test methods including C177 , C518 , and C335 . A key aspect of this guide is the notion of an insulation system, not an insulation material. Under the practical use environment of most cryogenic applications even a single-material system can still be a complex insulation system ( 1- 3 ) . 2 To determine the inherent thermal properties of insulation materials, the standard test methods as cited in this guide should be consulted. 1.2 The function of most cryogenic thermal insulation systems used in these applications is to maintain large temperature differences thereby providing high levels of thermal insulating performance. The combination of warm and cold boundary temperatures can be any two temperatures in the range of near 0 K to 400 K. Cold boundary temperatures typically range from 4 K to 100 K, but can be much higher such as 300 K. Warm boundary temperatures typically range from 250 K to 400 K, but can be much lower such as 40 K. Large temperature differences up to 300 K are typical. Testing for thermal performance at large temperature differences with one boundary at cryogenic temperature is typical and representative of most applications. Thermal performance as a function of temperature can also be evaluated or calculated in accordance with Practices C1058 or C1045 when sufficient information on the temperature profile and physical modeling are available. 1.3 The range of residual gas pressures for this Guide is from 10 -7 torr to 10 +3 torr (1.33 -5 Pa to 133 kPa) with different purge gases as required. Corresponding to the applications in cryogenic systems, three sub-ranges of vacuum are also defined: High Vacuum (HV) from 10 -6 torr to 10 -3 torr (1.333 -4 Pa to 0.133 Pa) [free molecular regime], Soft Vacuum (SV) from 10 -2 torr to 10 torr (from 1.33 Pa to 1,333 Pa) [transition regime], No Vacuum (NV) from 100 torr to 1000 torr (13.3 kPa to 133 kPa) [continuum regime]. 1.4 Thermal performance can vary by four orders of magnitude over the entire vacuum pressure range. Effective thermal conductivities can range from 0.010 mW/m-K to 100 mW/m-K. The primary governing factor in thermal performance is the pressure of the test environment. High vacuum insulation systems are often in the range from 0.05 mW/m-K to 2 mW/m-K while non-vacuum systems are typically in the range from 10 mW/m-K to 30 mW/m-K. Soft vacuum systems are generally between these two extremes ( 4 ) . Of particular demand is the very low thermal conductivity (very high thermal resistance) range in sub-ambient temperature environments. For example, careful delineation of test results in the range of 0.01 mW/m-K to 1 mW/m-K (from R-value 14,400 to R-value 144) is required as a matter of normal engineering applications for many cryogenic insulation systems ( 5- 7 ) . The application of effective thermal conductivity values to multilayer insulation (MLI) systems and other combinations of diverse materials, because they are highly anisotropic and specialized, must be done with due caution and full provision of supporting technical information ( 8 ) . The use of heat flux (W/m 2 ) is, in general, more suitable for reporting the thermal performance of MLI systems ( 9- 11 ) . 1.5 This guide covers different approaches for thermal performance measurement in sub-ambient temperature environments. The test apparatuses (apparatus) are divided into two categories: boiloff calorimetry and electrical power. Both absolute and comparative apparatuses are included. 1.6 This guide sets forth the general design requirements necessary to construct and operate a satisfactory test apparatus. A wide variety of apparatus constructions, test conditions, and operating conditions are covered. Detailed designs are not given but must be developed within the constraints of the general requirements. Examples of different cryogenic test apparatuses are found in the literature ( 12 ) . These apparatuses include boiloff types ( 13- 17 ) as well as electrical types ( 18- 21 ) . 1.7 These testing approaches are applicable to the measurement of a wide variety of specimens, ranging from opaque solids to porous or transparent materials, and a wide range of environmental conditions including measurements conducted at extremes of temperature and with various gases and over a range of pressures. Of particular importance is the ability to test highly anisotropic materials and systems such as multilayer insulation (MLI) systems ( 22- 25 ) . Other test methods are limited in this regard and do not cover the testing of MLI and other layered systems under the extreme cryogenic and vacuum conditions that are typical for these systems. 1.8 In order to ensure the level of precision and accuracy expected, users applying this standard must possess a working knowledge of the requirements of thermal measurements and testing practice and of the practical application of heat transfer theory relating to thermal insulation materials and systems. Detailed operating procedures, including design schematics and electrical drawings, should be available for each apparatus to ensure that tests are in accordance with this Guide. In addition, automated data collecting and handling systems connected to the apparatus must be verified as to their accuracy. Verification can be done by calibration and comparing data sets, which have known results associated with them, using computer models. 1.9 It is impractical to establish all details of design and construction of thermal insulation test equipment and to provide procedures covering all contingencies associated with the measurement of heat flow, extremely delicate thermal balances, high vacuum, temperature measurements, and general testing practices. The user may also find it necessary, when repairing or modifying the apparatus, to become a designer or builder, or both, on whom the demands for fundamental understanding and careful experimental technique are even greater. The test methodologies given here are for practical use and adaptation as well as to enable future development of improved equipment or procedures. 1.10 This guide does not specify all details necessary for the operation of the apparatus. Decisions on sampling, specimen selection, preconditioning, specimen mounting and positioning, the choice of test conditions, and the evaluation of test data shall follow applicable ASTM Test Methods, Guides, Practices or Product Specifications or governmental regulations. If no applicable standard exists, sound engineering judgment that reflects accepted heat transfer principles must be used and documented. 1.11 This guide allows a wide range of apparatus design and design accuracy to be used in order to satisfy the requirements of specific measurement problems. Compliance with a further specified test method should include a report with a discussion of the significant error factors involved as well the uncertainty of each reported variable. 1.12 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. Either SI or Imperial units may be used in the report, unless otherwise specified. 1.13 Safety precautions including normal handling and usage practices for the cryogen of use. Prior to operation of the apparatus with any potentially hazardous cryogen or fluid, a complete review of the design, construction, and installation of all systems shall be conducted. Safety practices and procedures regarding handling of hazardous fluids have been extensively developed and proven through many years of use. For systems containing hydrogen, particular attention shall be given to ensure the following precautions are addressed: (1) adequate ventilation in the test area, (2) prevention of leaks, (3) elimination of ignition sources, (4) fail safe design, and (5) redundancy provisions for fluid fill and vent lines. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.14 Major sections within this standard are arranged as follows: 1.15 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ISO 20088-3:2018
Determination of the resistance to cryogenic spillage of insulation materials - Part 3: Jet release
This document describes a method for determining the resistance of a cryogenic spill protection (CSP) system to a cryogenic jet as a result of a pressurized release which does not result in immersion conditions. It is applicable where CSP systems are installed on carbon steel and will be in contact with cryogenic fluids.
A cryogenic jet can be formed upon release from process equipment operating at pressure (e.g. some liquefaction processes utilize 40 to 60 bar operating pressure). Due to high pressure discharge, the cryogenic spillage protection can be compromised by the large momentum combined with extreme cryogenic temperature.
Although the test uses liquid nitrogen as the cryogenic liquid, the test described in this document is representative of a release of LNG, through a 20 mm orifice or less, at a release pressure of 6 barg or less, based upon simulated parameters 1 m from the release point. Confidence in this test being representative is based upon a comparison of the expected dynamic pressure of the simulated release in comparison with dynamic pressure from releases in accordance with this document.
It is not practical in this test to cover the whole range of cryogenic process conditions found in real plant conditions; in particular the test does not cover high pressure cryogenic jet releases that might be found in refrigeration circuits and in LNG streams immediately post-liquefaction.
Liquid nitrogen is used as the cryogenic medium due to the ability to safely handle the material at the pressures described in this document. The test condition is run at nominally 8 barg pressure.
ISO 20088-1 covers cryogenic release scenarios which can lead to pooling conditions for steel work protected by cryogenic spill protection as a result of a jet release or low pressure release of LNG or liquid nitrogen. ISO 20088-2 covers vapour phase exposure conditions as a result of a jet release or low pressure release of LNG or liquid nitrogen.
