Hydrogen Pipeline Safety

Our goal is to establish the codes and standards necessary to ensure safe distribution of hydrogen fuels. The future hydrogen economy will depend on efficient transport of fuel across the U.S., preferably using our existing network of oil and gas pipelines where hydrogen degradation is likely to occur. By establishing unique test facilities and standard test procedures, we will provide pipeline operators with critical data on the durability of pipeline materials in high-pressure gaseous hydrogen environments.

Embrittlement of steel microstructure due to exposure to hydrogen.

We are currently constructing a new laboratory to evaluate tests, materials, mechanical properties, and standards for hydrogen pipelines. Construction is just beginning on the 750-square-foot laboratory on the site of a former hydrogen test facility at the NIST campus in Boulder, Colorado. The laboratory, including a control room in a separate existing building, is expected to be operational by mid-2008. NIST researchers will use the hydrogen laboratory to develop long-term service tests and apply them to study pipeline materials and mechanical effects.

Preliminary research is already underway to determine the effect of hydrogen on pipeline steels. The compact tension specimens above were separately charged by gaseous hydrogen and then coated (right) to slow release of hydrogen from the microstructure. Significant differences in fatigue rates were observed due to charging.

Experiments will involve immersing materials in pressurized hydrogen gas contained in steel alloy test chambers. The largest of these, about the size of a small automobile gas tank, will be the nation's biggest hydrogen test chamber. Studies will be conducted using hydraulic machines to test mechanical fatigue, tensile strength, residual strength and fracture toughness. Initial research will involve collecting data for existing pipeline materials as a baseline and conducting "round robin" exercises to ensure consistency of tests among various hydrogen laboratories. In the future, the focus will expand to new materials such as composites.

In addition to mechanical data, we are also developing sensors to assess the extent of permeation of hydrogen into the steel microstructure. These sensors have already been field tested and provide a measure of hydrogen dissolution from sub-1 to 10s of ppm.

Contact sensor that monitors thermoelectric power, which varies with hydrogen uptake.