Lightning protection for LNG facility 3

[T83]

Hello,

I have some questions regarding lightning protection for a LNG facility,I am a fresh graduate and don't worry I am not designing the project but still I want to know some stuff.

Ok here it goes,I came across the drawings of a LNG project and they want to make a lightning protection system for it and I am wondering about the best way to go about it,I know how to go about a residential building,but I am interested on how to go around a facility..There are basically LNG tanks,water tanks,administration building,transformer/generator building,small building at the entrance,a pump house,and of course a station for trucks to get filled,so I am wondering what is best in such a case ?

First of all,the LNG tanks are made from metal but they are based on concrete so in my opinion we should simply ground the tanks, I am also thinking we should erect a tower(s) and make an air terminal system for lightning protection and if we go with the tower(s) idea would you still do lightning protection for the other buildings that I mentioned even though they are on lower levels or do you simply settle for having surge arrestors for the other buildings.Also,I am wondering about the secondary effects of lightning such as arcs being that this is an industrial facility and the presence of gases.

Second of all,what do you think about the Dissipation Array System,I mean it doesn't seem to be widely acceptable although it is starting to get popular,I read the theory that goes behind it and it seems interesting,but I am looking for opinions..

Also,what books do you recommend regarding lightning protection,I mean I am looking for something that only deals with the topic and goes through different cases beyond the residential aspect.

This is it and thx a lot for your time!

 

[oldfieldguy]

T83--

I am going to venture a bet that the LNG tanks are already grounded. I have worked around an LNG facility and everything in the plant was grounded in accordance with standard practice.

That said, another of my former clients elected to go with the dissipation array scheme for lightning protection. It seems to have solved problems they had with lightning strikes on well-grounded but very tall structures and other problem areas.

I was starting to investigate the dissipation array when I started work with my present employer. They were having some very bad problems with lightning wiping out instrumentation and control equipment at their stations. Before I got to the "Let's spend some major $$$ on dissipation arrays" stage, I audited the problem stations and had them go through and redo their grounding and bonding in accordance with best practices, then insert some commonly available surge suppressors into the equipment. The problems went away.

Another lightning-related issue caused erratic operation of distribution protection. This was traced back to an incomplete understanding of the possible power flows during faults caused by lightning strikes on overhead portions of the 13,800 volt distribution system. Changing the system's "normal operation" configuration (from closed tie breakers to open tie breakers) has resulted in no further problems.

Bottom line? Lightning protection and the problems associated with lightning can take you down many different paths.

Good luck!


old field guy

 

[alehman]

There may be some specific legal requirements and standards that apply to your situation. I would start by researching applicable codes. In the U.S., NFPA standard 780 is a good starting point for lightning protection requirements. I'd also have a discussion with the insurance company. They may have specific requirements or recommendations. In fact, they may have already done an audit of the facility.

 

[giuseppe]

Hi T83,

correctly, the NFPA 780 is good, but the best available is presently the new IEC EN 60305. Also, some API standards related to the matter will help. Finally, for sensitive equipment, specifically telecom, I will suggest to see the ITU, particularly the K27.

May I suggest you to join the NLSI forum for further researches and knowledge. The NLSI (

http://www.lightningsafety.com/)

is a fantastic way to keep in touch with authorities around the world on Lightning Protection Suystems.

Hope the above will help.

Good luck, then.

Giuseppe

 

[T83]

First things first,Thank you guys for your time !
Second of all,I got me a short summary of the NFPA 780 and it was really useful,there is a guy who suggested for me the "Lightning Protection Guide" from dehn you can find it at

http://www.dehn.co.uk

the material is for free,you will find in their downloads section a catalog regarding lightning protection and to your right "Lightning Protection Guide" it seems to cover almost every part.