Bolted Steel Tank Dismantling 1

[fareh]

Dears,

What are the applicable ways of Dismantling a bolted steel tank.

Background

The tank diameter is 26 meter and 10 meter height.
The tank has been on service for ten years.
the Tank Type is Bolted.

Thanks,
M.ALFAREH

 

[bimr]

Depends on the future use of the tank doesn't it?

 

[fareh]

The tank will go to scrap. It will not be used anymore.
I need to know what are the applicable ways to dismantle bolted tanks so we can use the best way to suit our capability.

 

[bimr]

Cut it up with a torch. Cut out segments and drop the pieces down with a crane. Start at the top and work your way down. You can cut off the bolts if you like.

http://www.etradeasia.com/products_detail/367461/735104/0/Vitrium_Enamel_Bolted_Tanks.html#a1

 

[fareh]

Thanks bimr,
what is the best way, (Safe, Time saving, efficient), that we can cut it out to segments

by welding machine
by grinder
by undoing the nuts
or other way

 

[darthsoilsguy2]

Oxy/Acetylene torch if the metal can rust. undoing nuts or using grinder if stainless steel.

 

[darthsoilsguy2]

i just read your other post and regret making a comment.... you must have somebody who has experience to do this. Your questions show a truly fundamental unfamiliarity with this. You in no way provided us with the information needed to say how to do this safely. All methods of disassembly are UNSAFE without an experienced tank demolition contractor at the helm. You need a solid approach to phase this work in a way that protects the workers. Trust me... you don't want ANY inexperienced demolition workers either.

 

[fareh]

Thanks darthsoilsguy2,

the tank is made of carbon steel, therefore, Oxy/Acetylene torch is the suitable way to dismantle it.
Is there any standards, recommendation, or common practice for such process?
I know it seems simple, cut and lift to the ground, but i am curious if there is any documented procedure.

Thanks,

 

[fareh]

Dear darthsoilsguy2,

thanks again for the comment above, No need to regret, your comment was helpful for me.

FYI, the dismantling work will be handled by fully experienced team and engineers, the regulations are very strict in our plant.
My post above is to allow me understand the applicable ways of dismantling in order to understand the discussions/proposals of the dismantling team and be ready to show them our concerns.

Thanks,

 

[fareh]

What do you think of using an electrical spanner to undo the nuts for the tank. Is it an efficient way compared to a torch?
photos of the tank attached.

Thanks,

 

[Syahar1975]

Farah,

I am fully agree with BIMR.

Erect scaffold full around the tank. Cut piece by piece using cutting torch. That lift by the crane put on the ground.

The scaffolding height must be adjusted to give a good access for the cutter and rigger.

This must be very old tanks. I don't think you can use electrical spanner to un-installed the bolts one by one.

The work just reverse from the erection. I mean we erect the tank from the bottom to the roof one by one so we dismantling from the roof to the bottom one by one as well.

Good luck

 

[IFRs]

Hire a demolition crew. They will bring in a nibbler and the tank will be gone in a day or less.

 

[fareh]

Thanks Syah, well elaborated.

Thanks IFRs, Demolition with Nibbler is not allowed, apiece by piece dismantling is required.

 

[MJCronin]

Where is the tank located and what were the contents ?

Were the former contents flammable or combustable or hazardous ?

What are you going to do about the partially embedded tank floor ?

Will the foundation also be demolished or do you intend on some kind of reuse ?

Foundation demolition will be formidable and require the use of power/air tools (jackhammers).

If power tools are allowed/required for foundation renovation.....then I do not understand why a nibbler would be banned.

What is the reasoning for this ?

MJCronin
Sr. Process Engineer

 

[fareh]

Dear MJCronin ,

Where is the tank located and what were the contents ?
It is in the accommodation area of portable water tank farm, the content was water.

Were the former contents flammable or combustable or hazardous ?
No

What are you going to do about the partially embedded tank floor ?
it shall be removed in a safe way then go to scrap

Will the foundation also be demolished or do you intend on some kind of reuse ?
the foundation will be demolished and replaced with a new one.

Foundation demolition will be formidable and require the use of power/air tools (jackhammers).
Yes, the foundation will be demolished with a jack hammer or air compressor hammer

If power tools are allowed/required for foundation renovation.....then I do not understand why a nibbler would be banned

What is the reasoning for this ?

Nibbler is not banned but demolition is not allowed due to client requirements, the tank shall be dismantled into pieces, even though, it will go to scrap.

Thanks,

 

[bimr]

http://www.google.com/url?sa=t&rct=...cd=1&cad=rja&uact=8&ved=0CB4QFjAA&url=http://

http://www.safeworkaustralia.gov.au...vYGADQ&usg=AFQjCNGNAB5Mb86Ccrj8zcK8wZ79VzefqQ

You might want to review some general safety guidelines. Covers issues such as paint, fire hazards, asbestos, etc.

 

[LittleInch]

Wow, what happened to that tank? Did the ground collapse causing the floor plates to rupture or did the tank leak and wash out the foundation?

First thing you need to do is fill in the hole with something solid.

If might seem initially a good idea to unbolt it, but with 10 years for paint and rust you'll spend so long trying to remove the bolts that you'll regret it. The sealing used will by now have the consistency of a super glue and the plates will not part very easily and could distort the tank. As per the posters above, I would scaffold this thing, attach some lifting pads to the roof and cut the roof off as a single element then cut plates out just below the original bolt line, both vertical and horizontal. Best cutter - probably torch, but you could use grinders - will just get gradually slower as you progress down the tank and take off one layer at a time.

Have no one inside the tank while your doing this as there is a risk a tank as damaged as this could just collapse inwards.

I would strongly urge you to employ a firm that has dismantled damaged tanks before because this could go horribly wrong.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[fareh]

Thanks Bimr,
Thanks LittleInch,

The tank had some leakage from bottom, The tank will be dismantles by experienced people and I need to understand the process.

 

[fareh]

Regarding the type of torch to be used,
Which type would be preferred in our case Gas torch or plasma Cutting torch.

the steel plates are about 10 mm thick and 2 m height and are glass coated.
In addition, is there a standard/recommended length of the pieces to be parted from the tank.

Thanks,

 

[bimr]

Acetylene welding torches are used. The size of the pieces will depend on the crane and other equipment. The steel on bolted tanks is usually thin material.