The Cryogenic Cam Butterfly Valve (CCV) is an innovative valve that can effectively operate across a wide range of temperatures, seal better than valves currently available on the market at those temperatures and can easily meet the demanding material requirements of a liquid oxygen (LOX) system. The CCV was designed to replace obsolete Royal/Hadley valves, which have been used at NASA’s Stennis Space Center (SSC) since the 1960’s as isolating valves in cryogenic fluid systems at SSC and have become costly to repair.
The CCV is innovative because it is the only butterfly valve that it can adapt to dynamic changes due to changing temperatures. Temperature changes cause materials to expand and contract. For example, a 12” long aluminum rod chilling down in liquid hydrogen (LH2) from room temperature to -423 degrees F will shorten the rod length by approximately 1/16”. This may seem like an insignificant change, but it can cause a significant leak if the critical dimension between the valve disc and seat change. Ideally, cryogenic valves should be able to compensate for these dynamic temperature changes and maintain a tight seal, but the different valves that were procured to replace the existing Royal/Hadley butterfly valves have not been successful passing the rigorous SSC cryogenic tests and material requirements for LOX systems. It is this inability of existing butterfly valves to reliably perform as needed which triggered the innovative design of the CCV.
The CCV can seal better than other butterfly valves on the market because of the dual movement possible in the hybrid design. To improve the sealing performance, the CCV combines the rotational movement of a butterfly with the translational movement of a globe valve.
The NASA SBIR Phase I Solicitation for 2019 identifies near-term operational cost reduction and improvements for ground test components by improving ground, launch and flight systems as areas of focus; this Proposal focuses on the development of an innovative cryogenic butterfly valve that will perform consistent and reliable at ambient and cryogenic temperatures. The CCV will eliminate the need for temperature specific testing (i.e., cryogenic environments) for components, while improving the performance reliability in the field.
Better cryogenic fluid flow control systems are anticipated for liquid hydrogen, liquid nitrogen, liquid oxygen and liquefied natural gas for the industrial gas, private space flight, electrical energy, chemical processing, and oil refining markets; these will be driven by market demand for more efficient, cleaner fuels, as well as more practical LNG transportation through the supply chain.