Question,
Our refining facility is bringing on line a new gasoline desulfurization unit. This unit has many hydrogen process streams.
Having very little experience with ultrasonics, would this be a good application for detecting hydrogen leakage from flanges,piping, valves, packing etc...?
If so, what systems would be preferred over others for this application.

Thanks in advance,
Robbie

Hello Robbie,
I have used an SDT170 with parabolic dish to successfully find hydrogen leaks in a refining application.
Normally the flow rates are not as high as in the case of compressed air leaks plus hydrogen tends to make less noise than air so using a sensor combination which gave enhanced sensitivity was critical.

Hope this helps,
Tom Murphy

Tom...Thanks for the info.
I have been looking at SDT and UE Systems instruments for this application. In your opinion which of the two or both would do a better job in this application? Also which models of choice(digital, analog etc...) would be recommended, including accessories that would also be beneficial for all around ultrasonic analysis?
I am presently a level 3 vibe analyst, but am always looking for additional tools for the toolbox.

Thanks in advance,
Robbie

Robbie,
Keep in mind hydrogen is still a gas of which most facilities use an IS Rated instrument. Check with your facilities safety rules and regulations. In a May 2007 UPTIME Magazine I wrote and article about finding hydrogen leaks in power plants titled "Hazards of Hidden Hydrogen".
Ultrasound is a great instrument to use for this application. Ultrasound listens for turbulence, it is not gas specific. There are only two instruments in the marketplace that are IS rated. SDT has the SDT120 and UE the UP2000.
If you have an ultrasound instrument on-site, check with the manufacturer of this unit about the its "explosive proof" rating or if it has one...
Also, within the May 2007 UPTIME article I also spoke about using a low-surface tension liquid to help locate the hydrogen leaks. The liquid creates bubbles that when they rise and pop, ultrasonically the leak can be heard.

Thanks for all advice. I have contacted one company for an on site demonstration to see if this technology will fit into our reliability program. I feel certain from what I have read and heard that ultrasound will be a useful tool in our refining facility.
If anyone would like to comment on applications useful in refining enviroment please let me(us) know.

Thanks,
Robbie

May we use Holoroyd's acoustic emission meter for the same purpose? We are presently using it for early bearing fault detection inthe form of distress value. It also works in ultrasonic range.
Regards
Irshad Akhtar

Akhtar:

I do not believe that Holroyd has an airborne sensor. Their sensors are for rotating equipment and require direct contact.

Both SDT and UE have both standard and parabolic air borne sensors. UE also has a more compact sensor called the Long Ranger. If you are looking for air borne gas leaks at a distance the long range sensors will increase sensitivity and, equally important, reduce interference from other ambient ultrasound sources.