This project was for the turnkey engineering, procurement, fabrication, and construction of two (2) new 500,000 gallon (net-working capacity), double-wall, green liquid hydrogen storage spheres for the Gateway Project in Alabama, New York, USA. Green hydrogen is produced using electricity to power an electrolyser that splits the hydrogen from water molecules.

The scope of work included the sphere foundations, the structure, nozzles, platforms, access stairway, the structure coatings and testing. Each sphere (outer and inner) is ASME Section VIII Div 1 code compliant. Unique in design, the 7-column sphere outer is carbon steel and the inner sphere, which is concentrically suspended inside the outer sphere and to withstand the -422 degree Fahrenheit design temperature, is stainless steel. Each inner sphere is designed for an internal pressure of 30 psig (45 psid) and an external pressure of 5 psig. Each outer sphere is designed for 5 psig internal pressure and full vacuum. The evacuated annular space between the inner and outer sphere is filled with perlite insulation to maintain the hydrogen product at liquid temperature. Both inner and outer sphere weld joints were inspected using Time of Flight Diffraction (TOFD) Ultrasonic Testing (UT) in lieu of Radiographic Testing (RT). Testing included inner sphere hydro-pneumatic, inner sphere and nozzle helium mass-spectrometer (HMS), outer sphere pneumatic, and vacuum retention testing.

These two spheres were successfully completed with zero incidents and ahead of the overall project schedule. With the completion of the balance of the plant, these spheres will be part of the largest Green Hydrogen Production Facility in North America.

Award Name

ASME Pressure Vessel

Company Name

CB&I New Castle

Award Year


Product Details

  • Liquid Hydrogen/Gateway Project
  • Plug Power
  • Alabama, N.Y.

Date Completed

July 28, 2023

Construction Standard

ASME Section VIII Div 1 (2019 Edition)

Overall Height


Column Height






Steel Tonnage Used


Steel Thickness


Affiliate Companies