CEN/TC 268/WG 2 - Compatibility, insulation, accessories

ISO 23208:2017 specifies the minimum requirements for the cleanliness of all surfaces of cryogenic vessels and associated accessories that are in contact with the cryogenic fluid at any expected operating conditions.
ISO 23208:2017 defines the acceptable level of surface and particle contamination to minimize the risk of malfunction of equipment and ensure safety against ignition when in contact with oxygen or oxidizing fluids (see ISO 10156).

ISO 21028-2:2018 specifies the toughness requirements of metallic materials for use at temperatures between −20 °C and −80 °C to ensure their suitability for cryogenic vessels. This document is applicable to fine-grain and low-alloyed steels with specified yield strength ≤460 N/mm2, aluminium and aluminium alloys, copper and copper alloys and austenitic stainless steels.
NOTE       For steel materials listed in EN 13445‑2 or EN 13480‑2 or for steel materials and weldings complying with the same fundamental safety requirements, the requirements for prevention of brittle fracture at low temperatures according to EN 13445‑2:2014, Annex B, method 2, or EN 13480‑2:2012, Annex B, method 2 can be applied.

ISO 21028-1:2016 specifies the toughness requirements of metallic materials for use at a temperature below -80 °C to ensure their suitability for cryogenic vessels.
ISO 21028-1:2016 is not applicable to unalloyed steels and cast materials.

ISO 21013-3:2016 provides separate calculation methods for determining the required mass flow to be relieved for each of the following specified conditions:
-      vacuum-insulated vessels with insulation system (outer jacket + insulating material) intact under normal vacuum, outer jacket at ambient temperature, inner vessel at temperature of the contents at the specified relieving pressure;
-      vacuum-insulated vessels with insulation system (outer jacket + insulating material) intact under normal vacuum, outer jacket at ambient temperature, inner vessel at temperature of the contents at the specified relieving pressure, pressure regulator of the pressure build-up system functioning at full potential;
-      vacuum or non-vacuum-insulated vessels with insulation system remaining in place, but with loss of vacuum in the case of vacuum-insulated vessels, outer jacket at ambient temperature, inner vessel at temperature of the contents at the specified relieving pressure or vacuum or non-vacuum-insulated vessels with insulation system remaining fully or partially in place, but with loss of vacuum in the case of vacuum-insulated vessels, fire engulfment, inner vessel at temperature of the contents at the specified relieving pressure;
-      vacuum-insulated vessels containing fluids with saturation temperature below 75 K at 1 bar with insulation system remaining in place, but with loss of vacuum with air or nitrogen in the vacuum space;
-      vacuum insulated vessels containing fluids with saturation temperature below 75 K at 1 bar with insulation system remaining in place, but with loss of vacuum with air or nitrogen in the vacuum space with fire engulfment;
-      vessels with insulation system totally lost and fire engulfment.
Good engineering practice based on well-established theoretical physical science needs to be adopted to determine the required mass flow where an appropriate calculation method is not provided for an applicable condition.
Recommendations for pressure relief devices for cryostats are given in Annex A.

ISO 24490:2016 specifies the minimum requirements for the design, manufacture and testing of pumps for cryogenic service.
ISO 24490:2016 is applicable to centrifugal pumps. However, it can be applied to other types of cryogenic pumps (e.g. reciprocating pumps), where applicable.
This International Standard also gives guidance on the design of installations (see Annex A).
It does not specify requirements for operation or maintenance.
NOTE          For cryogenic fluids, see ISO 21029‑1, ISO 20421‑1 and/or ISO 21009‑1.

This European Standard specifies the requirements for the design, manufacture and testing of safety valves for cryogenic service, that is to say for operation with cryogenic fluids (as defined in EN 1251-1) below – 10 °C in addition to operation at ambient temperature. It is a requirement of this European Standard that the valves comply with EN ISO 4126 1 or EN ISO 4126-4. In the event of different requirements, the requirements for cryogenic service shall be applied.
NOTE 1   A cryogenic fluid (refrigerated liquefied gas) is a gas which is partially liquid because of its low temperature (including totally evaporated liquids and supercritical fluids).
This European Standard is restricted to valves not exceeding a size of DN 100 for category B. The valves of category A are limited to DN 25 and set pressures up to 40 bars. Both categories are designed to relieve single phase vapours or gases. A valve can be specified, constructed and tested such that it is suitable for use with more than one gas or with mixtures of gases.
NOTE 2   All safety valves covered in this European Standard correspond to category IV of PED (Directive 97/23/EC) and category 3 of TPED (Directive 99/36/EC).
NOTE 3   This European Standard does not provide methods for determining the capacity of relief valve(s) for a particular cryogenic vessel. Such methods are provided in EN 13648 3.

This European Standard specifies the requirements for the design, manufacture and testing of valves for cryogenic service, i.e. for operation with cryogenic fluids (as defined in EN 1251-1) below - 10 °C as well as at ambient conditions to allow for start-up and run-down. It specifies additional requirements for cryogenic service for the appropriate valve product standard.
NOTE   a cryogenic fluid (refrigerated liquefied gas) is a gas which is partially liquid because of its low temperature (including totally evaporated liquids and supercritical fluids).
It applies to sizes up to DN 150 including vacuum jacketed cryogenic valves.
This European Standard is not applicable to safety valves and valves for liquefied natural gas (LNG).
It is intended that the valve be designed and tested to satisfy a pressure rating (PN or Class). Valves may then be selected with a PN or Class equal to or greater than the maximum allowable pressure (PS) of the equipment with  which it is to be used.

TC - Replace Figures

TC - Replace Figures

TC - Replace Figures

Inner vessel stiffening rings.

This European Standard specifies requirements for the design, fabrication, inspection and testing of static non-vacuum insulated cryogenic vessels designed for a maximum allowable pressure of more than 0,5 bar.
This European standard applies to static non-vacuum insulated cryogenic vessels for fluids as specified in prEN 14197-1 and does not apply to vessels designed for toxic fluids.
For static non-vacuum insulated cryogenic vessels designed for a maximum allowable pressure of not more than 0,5 bar this European Standard may be used as a guide

This European Standard specifies the fundamental requirements for large transportable non-vacuum insulated cryogenic vessels and designed to operate above atmospheric pressure.
This standard applies to large transportable non-vacuum insulated cryogenic vessels for fluids as specified in 3.1 and is not applicable to such vessels designed for toxic fluids.

This European Standard specifies the fundamental requirements for static non vacuum insulated cryogenic vessels designed for a maximum allowable pressure greater than 0,5 bar.
This European Standard applies to static non vacuum insulated cryogenic vessels for fluids as specified in 3.1.
For static non vacuum insulated cryogenic vessels designed for a maximum allowable pressure of not more than 0.5 bar, this European Standard may be used as a guide.
This European Standard is not applicable to vessels built on-site.

This European Standard specifies requirements for the design, fabrication, inspection and testing of large transportable vacuum insulated cryogenic vessels of more than 1 000 l volume, which are permanently (fixed tanks) or not permanently (demountable tanks) attached to a vehicle, for carriage by road. However, it can be used for other mode of transport providing the specific regulations/requirements are complied with.
This European Standard applies to large transportable vacuum insulated cryogenic vessels for fluids specified in prEN 13530-1:2001 and does not apply to vessels designed for toxic fluids.
This European Standard does not include the general vehicle requirements e.g. running gear, brakes, lighting etc. that should be in accordance with the relevant standards/regulations.

This European Standard specifies the requirements for the design, manufacture and testing of bursting disc safety devices for cryogenic service, i.e. for operation with cryogenic fluids below - 10 °C in addition to operation at ambient temperature. It is a requirement of this standard that the bursting disc safety device(s) comply with prEN ISO 4126-2. In the event of different requirements, this standard takes precedence over that standard.
This standard is restricted to bursting disc safety devices not exceeding a size of DN 100 designed to relieve single phase vapours or gases. A bursting disc assembly can be specified, constructed and tested such that it is suitable for  use with more than one gas or with mixtures of gases.
NOTE   This standard does not provide methods for determining the capacity of bursting disc safety devices for a particular cryogenic vessel. Such methods are provided in prEN 13648-3.

This European Standard specifies the fundamental requirements for static vacuum insulated cryogenic vessels designed for a maximum allowable pressure greater than 0,5 bar.
This European Standard applies to static vacuum insulated cryogenic vessels for fluids as specified in 3.1.
For static vacuum insulated cryogenic vessels designed for a maximum allowable pressure of not more than 0,5 bar, this standard may be used as a guide.
This European Standard is not applicable to vessels built on-site.

This European Standard specifies the fundamental requirements for large transportable vacuum insulated cryogenic vessels and designed to operate above atmospheric pressure. Appropriate parts may be used as a guidance for vessels designed to operate to the atmosphere. This standard applies to large transportable vacuum insulated cryogenic vessels for fluids as specified in 3.1 and is not applicable to such vessels designed for toxic fluids.

This standard is applicable to the design, fabrication, inspection and testing of static vacuum insulated cryogenic vessels designed for a maximum allowable pressure of more than 0,5 bar. This standard applies to static vacuum insulated cryogenic vessels for fluids as specified in WI 00268006 and is not applicable to vessels designed for toxic fluids. For static vacuum insulated cryogenic vessels designed for a maximum allowable pressure of not more than 0,5 bar this standard may be used as a guide.

This European Standard specifies the minimum requirements for the design, manufacture and testing of couplings for cryogenic service to be used for temporary connecting of flexible hoses to cryogenic vessels at the following operating conditions :
- design temperature range from - 270 ° C to + 65 ° C ;
- maximum nominal pressure : 80 bar ;
- nominal size (DN) from 10 to 100.
Permanent connections such as flanges and unions are not covered by this standard.
It is intended that the couplings should be designed, tested and marked for service at one of the generally accepted pressure e.g. PN 40. Couplings can then be selected with a PN equal to or greater than the maximum allowable pressure (PS) of the equipment for which they are to be used.

This European Standard is applicable to the design, fabrication, inspection and testing of transportable vacuum insulated cryogenic vessels of not more than 1000 litres volume and designed for a maximum allowable pressure greater than atmospheric. This standard applies to transportable vacuum insulated cryogenic vessels for fluids as specified in prEN 1251-1 and is not applicable to such vessels designed for toxic fluids.

This standard specifies the fundamental requirements for transportable vacuum insulated cryogenic vessels of not more than 1000 litres volume and designed to operate above atmospheric pressure. Appropriate parts may be used as a guidance for vessels designed to operate to the atmosphere. This standard applies to transportable vacuum insulated cryogenic vessels for fluids as specified in 3.1 and is not applicable to such vessels designed for toxic fluids.

This standard defines a pratical method for determining the heat leak performance of cryogenic vessels. The methods include measurement on both open and closed systems. This standard neither specify the requirement levels for insulation performance nor when the methodology defined is applied. These requirements may be defined in design or operational standards/regulations.

ISO 21012:2018 specifies design, construction, type and production testing, and marking requirements for non-insulated cryogenic flexible hoses used for the transfer of cryogenic fluids within the following range of operating conditions:
-      working temperature: from −270 °C to +65 °C;
-      nominal size (DN): from 10 to 100.
End fittings for mounting of any couplings are within the scope of this document, but the couplings are subject to other standards.
ISO 21012:2018 is intended that the hose be designed and tested to satisfy the generally accepted rated pressure i.e. at least PR 40. Hoses may be then selected with a PR equal to or greater than the maximum allowable pressure (PS) of the equipment to which it is to be used.

This standard specifies the minimum requirements for the cleanliness of all surfaces of cryogenic vessels and associated accessories, that are in contact with the cryogenic fluid at any expected operating conditions.  This standard defines the acceptable level of surface and particle contamination to minimize the risk of malfunction of equipment and ensure safety against ignition when in contact with oxygen or oxidizing fluids (see EN 720-2).

This standard gives design, construction, type and production testing, and marking requirements for non insulated cryogenic flexible hose used for the transfer of cryogenic fluids within the following range of operating conditions : - working temperature: from - 270 °C to + 65 °C ; - maximum nominal pressure: 80 bar ; - nominal size (DN): from 10 to 100. End fittings for mounting of any couplings are within the scope of this standard, but the couplings are subject to other standards. It is intended that the hose be designed and tested to satisfy the generally accepted nominal pressure e.g. PN 40. Hoses may then be selected with a PN equal to or greater than the maximum allowable pressure (PS) of the equipment to which it is to be used.

This European Standard specifies the toughness requirements of the metallic materials for use at a temperature between - 80 °C and - 20 °C ensuring suitability for use for the cryogenic vessels.
Fine grain and low alloyed steels with specified yield strength <= 460 N/mm², aluminium and aluminium alloys, copper and copper alloys and austenitic stainless steels are covered by this standard.

This European standard specifies the toughness requirements of metallic materials for use at a temperature below - 80 øC to ensure their suitability for cryogenic vessels.  This standard is not applicable to unalloyed steels and cast materials.  This standard is not applicable to cryogenic vessels for liquefied natural gas (LNG).

This standard provides a separate calculation method for determining the contributing mass flow to be relieved resulting from each of the following specified conditions:
- vacuum insulated vessels with insulation system (outer jacket + insulating material) intact under normal vacuum. Outer jacket at ambient temperature. Inner vessel at temperature of the contents at the relieving pressure;
- vacuum insulated vessels with insulation system remaining in place but with loss of vacuum, or non vacuum insulated vessels with insulation system intact. Outer jacket at ambient temperature. Inner vessel at temperature of the contents at the relieving pressure;
- vacuum or non vacuum insulated vessels with insulation system remaining fully or partially in place, but with loss of vacuum in the case of vacuum insulated vessels, and fire engulfment. Inner vessel at temperature of the contents at the relieving pressure;
- vessels with insulation system totally lost and fire engulfment.
Good engineering practice based on well established theoretical physical science shall be adopted to determine the contributing mass flow where an appropriate calculation method is not provided for an applicable condition.

This standard specifies the minimum requirements for the design, manufacture and testing of pumps for cryogenic service (i.e. for operation with cryogenic fluids below -10°C). This standard covers centrifugal pumps. However the principles may be applied to other types of pumps (e.g. reciprocating). This standard also gives guidance on the design of installations. (See annex A). It does not specify requirements on operation or maintenance.

This European Standard specifies the requirements for the design, manufacture and testing of safety valves for cryogenic service, i.e. for operation with cryogenic fluids below - 10 °C in addition to operation at ambient temperature. It is a requirement of this standard that the valves comply with prEN ISO 4126-1:2001. In the event of different requirements, this standard takes precedence over that standard.
This standard is restricted to valves not exceeding a size of DN 100 designed to relieve single phase vapours or gases. A valve can be specified, constructed and tested such that it is suitable for use with more than one gas or with mixtures of gases.
NOTE   This standard does not provide methods for determining the capacity of relief valve(s) for a particular cryogenic vessel. Such methods are provided in prEN 13648-3.

This standard specifies the requirements for the design, manufacture and testing of valves for cryogenic service, i.e. for operation with cryogenic fluids (as defined in prEN 1251-1:1995) below - 10 øC as well as at ambient conditions to allow for start-up and run-down. It specifies additional requirements for cryogenic service for the appropriate valve product standard.  It applies to sizes up to DN 150 and vacuum jacketed cryogenic valves. This standard is not applicable to safety valves and valves for liquefied natural gas (LNG).  It is intended that the valve be designed and tested to satisfy the generally accepted nominal pressure e.g. PN 40. Valves may then be selected with a PN equal to or greater than the maximum allowable pressure (PS) of the equipment to which it is to be used.

This Standard specifies the general requirements and defines the testing methods for establishing oxygen compatibility of materials (metallic and non-metallic) to be used for the manufacture of cryogenic vessels and associated equipment.  It mainly deals with materials that are normally or could be in contact with liquid/gaseous oxygen e.g., materials for cryogenic vessels used for the storage and/or transport of liquid oxygen.  It also deals with the materials which can be in contact with oxygen enriched environment e.g. insulating materials used for nitrogen, neon, hydrogen and helium cryogenic vessels where air condensation is possible.