Guidelines for Integrity Management of H2 Pipelines
Joint Industry Project
A Joint Industry Project to develop guidelines on assessing defects in pipelines for transporting H2 blends.
Enabling H2 transport via transmission pipelines
There are currently various efforts focused on enabling H2 transport via transmission pipelines. The initial focus of these efforts is based on enabling the blending of low concentrations of H2 with natural gas, with the longer-term goal being transporting 100% H2. Pipeline infrastructure is subject to complex loading situations ranging from ripple loading, pressure cycling, and geo-technical loading from earth movement. The presence of an embrittling agent like H2 exacerbates the damage associated with these loading events. Hence, one of the primary concerns with transporting H2 blends is the embrittlement of steels used in the pipeline infrastructure. In particular, the susceptibility to hydrogen embrittlement of vintage grade steels that have pre-existing defects, both on the ID and OD surface needs to be assessed.
The existing practice for assessing defects in H2 service is based on guidance from ASME B31.12. However, the information developed in ASME B31.12 is based on the response of in high pressure H2 (21MPa and higher). Additionally, the guidance provided in ASMEB31.12 is prescriptive and does not consider the use of lower-strength steels at lower pressures of H2. It is also important to note that the data developed for ASMEB31.12 does not consider the loading modes that the pipelines are subjected to in service.
A framework for the feasibility of transporting H2 blends in existing pipelines and the construction of new pipelines for H2 service.
The focus of the current JIP is to develop guidelines on assessing defects in pipelines for transporting H2 blends. The guidelines will be based on compiling information from various ongoing industry efforts as well as developing specific information on relevant materials under representative environmental and loading conditions. The guidelines will provide a framework to assess the feasibility of transporting H2 blends in existing pipelines along with providing a basis for the construction of new pipelines for H2 service.
Benefits of the JIP
It is expected that the JIP will provide the following significant benefits to the sponsor group:
- The properties of relevant FCGR and FT in relevant environments and loading conditions.
- The role of metallurgical variables on the FCGR and FT parameters in H2 to enable the development of guidelines for defect assessment in existing as well as new pipelines.
- An integrity management framework based on representative properties of relevant materials in typical operating environments.