FSEC
Patent Application Marks Successful Development of New Hydrogen
Leak-Detection Compounds
Monitoring hydrogen storage and usage sites for leakage is a crucial
step in a safe operations plan. To assist NASA in readily discerning the
presence of hydrogen leaks, researchers at FSEC have been developing methods
for detecting the presence of hydrogen.
Since it is such a light gas, diffusing readily, its leakage from a storage
tank, in transport or during use can pose potential safety problems. Because
hydrogen is also invisible and odorless, developing a system that provides
greater ease of use than the currently-employed sensors has been a great
challenge.
FSEC has filed for a provisional patent before the U.S. Patent
and Trademark Office on several formulations dubbed by the researchers
as “smart
paints for sensing hydrogen gas.”
The “smart paints” reveal, in an easy-to-see manner, the
presence of hydrogen due to minute gas leaks. Drs. Nahid Mohajeri,
Gary Bokerman, Nazim Muradov and Ali T-Raissi have been working on these
materials under a grant provided by the NASA-Glenn Research Center. Hydrogen
is a propellant used by NASA for launching the Space Shuttle and other
space vehicles at Kennedy Space Center.
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The dark spot in the "smart paint" tape
indicates a hydrogen leak around the flange.
(Photo: Nick Waters ) |
Unlike natural gas leaks that can be easily detected by their odor, hydrogen
leaks are difficult to detect. Operations at NASA facilities
require the use of extremely pure hydrogen with no additives to the gas
permitted. The FSEC technique provides a visual method to detect and locate
possible hydrogen leaks that may occur in the field lines, flanges and
joints for hydrogen transport and use.
To ensure that hydrogen leaks can be readily detected visually, FSEC
researchers, in collaboration with the NASA-KSC colleagues, have
been modifying existing formulations and developing new ones
to provide easy application and unambiguous results.
The “smart paint” can be applied in various forms at pipe
connections, valve joints, or other points that may be susceptible
to leaks. When there is a hydrogen leak, the paint changes color,
alerting technicians to correct the problem. The “smart pigments
and paints” have
been formulated to change color irreversibly for one time-use,
with the color variation remaining even when the hydrogen is
no longer present. This system has been field tested at NASA-KSC,
and sample kits have been sent to other NASA Centers for evaluation
and feedback.
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A roll of "smart paint" tape.
(Photo: Nick Waters ) |
Alternative applications use chemochromic tapes impregnated with the “smart
pigment.” FSEC researchers have also developed special tungsten-based
pigments that revert to the original color after hydrogen leak
has ceased. These special reversible pigments, intended for “repeated
use” applications,
have been prepared and are currently undergoing field testing
at NASA-KSC.
Researchers plan to continue development, field testing and weathering
assessment of the repeated use and one time-use articles suitable
for service in temperatures as low as –359° F. Additionally, efforts
will continue toward lowering the overall production costs of
the chemochromic materials.
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