5 replies to this topic

[von1987]

Hi there,

I'm a recent graduate and have not worked on site before, not sure whether I should be posting this here or not. Anyway, I'm doing a research on different types of storage tanks in industrial plants (I am working for a Process Safety company and need to know the safety behaviour of different storage tanks) and I can not seem to find enough detailed information for gas storage.

Basically I would like to know how industrial gases are stored if they are NOT liquefied (I found alot of info for liquefied gas tanks). I would like to know whether Pressurised Gas Storage Tanks are used? Are they in the form of Gas Cylinders? I am not sure whether Gas Cylinders are used in industrial plants because they seem to store a very small volume (I only found information for gas cylinders applied for laboratory uses, cooking purposes etc).

I would much appreciate a reply. Thanks!

[Art Montemayor]

von:

I can tell you more than you would like to know about gas storage and transport systems - as gases, not liquids. I can also direct you to where you can get official and helpful information.

However, in order not to waste time and effort trying to guess what part of the world you are working in or interested in finding out about, please tell me your location and other pertinent details, like the identities of some of the gases - although I can probably guess the majority of them. But why force me to guess? Just furnish the details.

Await your reply.

[von1987]

Dear Art Montemayor,

Sorry for not providing enough details.

I am working in a Process Safety Software company which is developing a software to automate HAZOPs for industrial plants.

My current task is to work on Safety Models (initially done on excel) for different types of storage tanks. What I mean by safety models are actually HAZOPs for each equipment. However, these models are only meant to be generic models, hence I am only supposed to think of generic faults and consequences i.e for a tank: More Flow gives Possible Overfilling. When a HAZOP team uses this software, they will reduce their time by only adding on the more detailed faults and conseuquences relevant to the plant they are working on.

Therefore I am unable to provide any information regarding the identities of the gases. I can however, tell you the type of models Im working on for you to get an overall picture on what I'm doing:

FOR LIQUIDS: Fixed Roof Atm Tank, Floating Roof Atm Tank (Internal and External), Pressurised Storage Sphere, Pressurised Liquid Tank

FOR GASES:
Liquified Gas: Cryogenic Atm Tank
In Gas Form: Pressurised Storage Sphere? Gas Cylinder? Atmospheric Gas Holder?

I hope this information will make it clearer on what type of information I am seeking. It would be good also to know whether there are additional models I could add and hear your comments on how you would categorise different tanks. Looking forward for your reply.


Regards,
Von

[Art Montemayor]

Von:

I was hoping to find out whether you are located in the USA or elsewhere. The reason being that I strongly recommend you resort to reading and studying the Compressed Gas Association (CGA) publications here in the USA. From your spelling, I would guess that you might be in Canada, but I’m not sure. Nevertheless, the CGA has the subject well covered and discussed. Go to: http://www.cganet.com/ where you will find available publications on the subject. Specifically, I recommend you obtain and study “The Handbook of Compressed Gases”. This comprehensive reference book addresses the properties, safety considerations, equipment, and regulatory requirements for properly transporting, handling, and using compressed gases and compressed gas containers. Written in clear, concise language, this handbook is both a comprehensive overview and a source reference for supplementary data concerning every aspect of handling gases in compressed, liquefied, and cryogenic form.

You will also find available booklets on each of the many individual industrial gases – from Acetylene to Xenon. You will find information at this site on such practical matters as

• Standards & Specifications
• Cylinders
• Equipment
• Industrial Gases
• Hydrogen
• Medical Gases
• Protection and Safe Handling
• Pressure Relief Devices
• Valve Connections

When you get into the industrial and medical gas industry you will find that there are really not any hazards that have not been evaluated, contemplated, and designed for. I know this after working in the industry for 10 years, right out of university. I designed for, produced, and delivered a lot of gas during that time – in gaseous, liquid, or solid phase.

During my career a lot of modifications were made in the industry to shift from producing and shipping gas in the traditional high pressure cylinders to bulk, liquefied distribution, storage, and utilization. Therefore, we had to adjust our safety methods to incorporate the hazards involved in the cryogenics and liquids arena. But a lot of gases, as you are noting, are still handled in the traditional compressed cylinders – especially medical and specialty gases that are typified by their ultra high-purity.

Please bear in mind that when you speak of the compressed gas industry, you are using a general term. In actuality some of the more common gases are not “compressed gases” but rather liquefied gases that exist in the compressed cylinders as saturated liquid. Some examples are Carbon Dioxide and Nitrous Oxide. Another exception is the ever-hazardous Acetylene, that is actually not even handled as a gas or as a liquid – but rather as a dissolved gas within a liquid (Acetone). It is exceedingly important to always bear these facts in mind because the obvious difference in hazards are inherently there.

All compressed gas cylinders, to my knowledge carry a mandatory rupture disc within the cylinder’s valve. Some are lead based to assist in quickly relieving during a fire case. And all compressed gas cylinders (with the exception of Acetylene) are hydrostatically tested on a routine basis and marked with a peened stamp to indicate the test date. I always tested my cylinders no longer than once every 3 years. And all hydrotests are documented for pressure and expansion and retained as legal proof.

You will note that there is a specific valve and a specific type of threaded connection with respect to each specific gas or gas mixture. This, of course, is the first step in avoiding a careless mistake in identifying what gas is within a cylinder. Color coding of cylinders is yet another way of also detecting which is which.

I could write on and on about this subject but this Forum is not the place for that. Suffice it to say that most of what I know is probably in the CGA’s “Handbook of Compressed Gases”.

I hope this experience is of some help.

[von1987]

Mr Art Montemayor,

Thank you very much for your detailed response towards my question, your expertise has definitely been a great help for me to understand what I am working on. By the way, I am Malaysian but I am experiencing my first job in UK after having completed my degree in chemical engineering over here. I have visited the CGA website but am unable to acess the publications as I am not a member. However I was able to view bits of the Handbook of Compressed Gases via Google Books. I think I might not be able to obtain the book in time to finish my models. Having a better understanding now, I will continue to search for more information via IChemE's Knovel Library and the internet.

The information on thie forum has been a great help for me all this while. Thank you once again for sharing your experience with young engineers like us. I look forward to learning more from you.


Regards,
Von

[Art Montemayor]

Von:

You do not have to be a member or suscriber of the CGA in order to purchase its publications. I don't know how you got that idea.

Here are some websites where you can get information:

Handling Liquefied Compressed Gas
http://www.airproduc...afetygram30.pdf

Large capacity gas tubes and tube trailers
http://www.fibatech.com/

Compressed gas cylinder safety
http://www.ehs.uiuc....ts/compgas.aspx