Quantity and Pressure limitation

This LAP¨refers to the quantity and pressure limitations. It underlines what are the requirements and limitations in terms of pressure and quantity of hydrogen for hydrogen transport. Finally, it shows if it is possible to increase the pressure/quantity, and if yes which authority is competent, what is the process to follow, how long does it takes and what are the costs associated if known.

Glossary:

Quantity and Pressure limitation represent the maximum quantity and/or pressure of gases which is allowed to be transported.

Pan-European Assessment:

There is no limitation in terms of pressure, (mostly transported at around 200-300 bars) In terms of quantity, the limitation is connected to the maximum weight the truck can transport.
Is it a barrier?
Yes
Type of Barrier
Structural barrier
Assessment Severity
2
Assessment
Currently, the high safety factors in regulations ( ADR,TPED) have restricted the increase of payload of hydrogen trailers and restricted the cylinder/tube volume. The availability of low–weight, high volume composite vessels makes it possible to increase the payload which would result in lower delivery costs to the end–users. In order to increase the pressure and/or volume of hydrogen receptacles the relevant standards have to be changed and adopted, the ADR has to be changed as to reference to the new standards, the ADR Directive and TPED have to be amended, the EU Member States have to transpose the ner rules in the national legislation.

Questions:

Question 1 What are the pressure requirements and limitations accepted for hydrogen transport by road?
ADR does not restrict pressure limits for hydrogen transport, but the pressure receptacle should have a safety factor 3. The safety factor is defined as the ratio between the burst pressure and the nominal fill pressure.
Question 2 What are the quantity requirements and limitations accepted for hydrogen transport by road?
The limitation of hydrogen quantties to be transported are assossiated with the volume limitations of the cylinders and tubes used and the maximum allowed weight of the transport vehicle (up to 40t in Germany).According to the UN Model regulations on the transport of dangerous goods, ADR European Agreement and the Transportable Pressure Equipment Directive the cylinder/tube volumes for transport of compressed gases are restricted (450l for cylinders and 3.000l for tubes. A new ISO standard ISO/DIS 17519:2017(E) “Gas cylinders — Refillable permanently mounted composite tubes for transportation” is currently under development giving the following limitations: Tubes covered by the requirements of this standard are: a) of composite construction, permanently mounted in a transport frame and suitable for specified service conditions, designated as: 1) Type 3 – a fully wrapped tube with a seamless metallic liner and composite reinforcement on both the cylindrical part and the dome ends; or 2) Type 4 – a fully wrapped tube with a non–load sharing liner and composite reinforcement on both the cylindrical part and the dome ends. b) with water capacities from 450 l up to 10.000 l; c) with working pressure up to 1000 bar This standard does not address tubes with working pressure times water capacity (p x V) more than 3 000 000 (MPa – L). This draft standard shows new future limits.
Describe the comparable technology and its relevance with regard to hydrogen
Transportable pressure equipment for compressed gases Compatibility of materials with hydrogen among industrial gases experts is common knowledge. In addition international standards exist and show which materials are compatible with hydrogen. An international standard exists, describing methods on how to select hydrogen compatible steels (ISO 11114–4: Transportable gas cylinders — Compatibility of cylinder and valve materials with gas contents — Part 4: Test methods for selecting steels resistant to hydrogen embrittlement.

National legislation:

EU Legislation: