Deco Chamber

[rmediver2002]

The equipment specifications for the vessel itself can be found under ASME-PVHO-1

The Coast Guard also sets specific standards for pressure vessels human occupancy in addition to the guidelines in ASME-PVHO-1:

http://frwebgate.access.gpo.gov/cgi...E=46&PART=197&SECTION=328&YEAR=1998&TYPE=TEXT

http://frwebgate.access.gpo.gov/cgi...E=46&PART=197&SECTION=332&YEAR=1998&TYPE=TEXT

Let me know if you need any specific info on accessory items or sources.

The yahoo group for Sub Ocean safety is still active, you would definately want to speak with Robert Izdepski. He may be of great help to you with procurement or advice on procurement of a system.

http://groups.yahoo.com/group/suboceansafety/

 

[Jean eve]

Thanks everybody for the reply including those with sacarsm But specially thanks to 'cacun Mark and rmediver2002'!You all had helping me a lot with the information provided.

Re the O2 chamber in the link that combusted, O2 filled hyperbaric and recom chambers have been exploding for years, with predictably ghastly results. The solution is simple - don't fill the chamber with straight 02! Most modern chambers are pressurized with air, and O2 masks which dump overboard are used to provide higher FO2s as necessary, so the FO@ in the chamber itself does not creep upward.

Concerning about the accident in S.Africa,I think fill the chamber with straight O2 is the main course.
Most of the butane tank pressure was between 17-30bar,and we don't send it for annual checking but seldom heard that it explode by itself.So for me to build a chamber which can withstand 7-8bar of pressure is not a main problem.The main problem for me is the equipment needed.
If because of what had happen in S.Africa,one shouldn't built a chamber by himself.Then I think we should totally ban of using Alu tanks since there is so many alu tanks exploded cases!But we don't judge one thing in one side,that is why even there are so many Alu tanks explode ,we're still using it.Because we knew that it is 6351 alu and maybe some don't go for annual checking and etc.....

 

[iain/hsm]

Does anyone on board know how is a deco chamber are built?What are the main things needed?
Thanks

Jean.

Most deck decompression chambers (DDC) are 54 to 60 inch diameter with a depth rating of 165 to 330 FSW (50 to 100 MSW) most in steel boiler plate from 8 to 12mm thick plate.

Provided you have a detailed engineering specification and detailed drawings to say ASME VIII div one or two and a third party approval of your design, say Lloyds, ABS TuV PVHO you should be able to use a local approved welding/fabrication shop. The shop would have to be approved with the above, submit welding procedures and qualifications and be able to manipulate, (turn roll handle) the size of vessel your after.
Normally apx 10 drawings and 20 page technical specification.

During main component fabrication as they are done all main welds need x ray, before they are attached to the next componant, heads and nozzels need dye pen, the innner lock seam needs ultrasonic testing all from a third party inspection house. After complete assy a hydrostatic test 1 hour each separate lock including the medical lock. The viewports are normally to a code Pressure Vessal Human Occupancy, and have there own certification.

Whilst it is quite possible to use a local coded welding shop for fabrication of your design. the problems they will face will be the door mechanism, safety interlocks on the medical/food lock, view ports and fitting out. Shot blasting is to SA2.5 but be careful with the type of paint used inside.

The small lighweight 180FSW (55MSW) "fly away" chambers used on small craft, take two people, use very little gas and can handle oxy/helium 50/50 mixtures that will reduce the TTUP and the stored gas used in the chamber by hours!

Pics of three types enclosed 50MSW, 100MSW and 250MSW

 

[Charlie99]

Asking about pressurized recompression chamber.
But thanks anyway for your DIY 'dry habitat'

I wouldn't dismiss RichLockyer's comments without considering that alternative a bit further.

The main problem with a "habitat" rather than an above water chamber would be for those very serious cases where the diver is severely incapacitated and can't get down to the habitat by himself.

A dry habitat or bell at 9 meters with a large O2 supply might not be 100% as good as a full hyperbaric chamber, but it would be a lot better than nothing.

Hopefully, you have already prepared the equipment and trained a team for in-water-recompression (see http://www.bishopmuseum.org/research/treks/palautz97/iwr.html as an example).

My apologies in advance, if you have already done these things and are now moving forward with the much better (and much bigger investment) system of a hyperbaric chamber.

 

[Seabear70]

Does anyone on board know how is a deco chamber are built?What are the main things needed?
or
Does anyone have the link of:
How to make a deco chamber?
Thanks

Ok, I've got several thousand hours on or in a deco chamber, and my advise would be to not try to build one. I really mean this, it may appear to be a simple undertaking, but there are so man things that can go wrong that you do not even want to think about it.

That being said, here's what you will need.

A wire welder in the 400 Amp Range. Two presure vessels, capable of a minimum of 1000 psi that can be attached through collars or by welding (yes, you ar right, usually the outer and inner locks are seperated sections of one vessel, but it could be done this way, and it may be easier to find the nessecarry parts for this.) Two doors capable of sustaining at a minimum 1000psi (Note, I am stating the arbitrary figure of 1000 psi, not because of any set requirement, but because it would never likely be required to handle more that say 300 ft. This provides quite a bit of fudge factor in the design.) Several flanges for observation ports, some 2 in thick lexan. Various fittings and pipes, and a very large life support rated Air Compressor.

When you getthe pressure vessels (note that one must be large enough to lay down in), let me know, and I can whip up a design for you.

Once again, this is a really bad Idea, sorry, but those things can kill you if you do not know exactly what you are doing.

 

[Seabear70]

Jean.

Most deck decompression chambers (DDC) are 54 to 60 inch diameter with a depth rating of 165 to 330 FSW (50 to 100 MSW) most in steel boiler plate from 8 to 12mm thick plate.

Provided you have a detailed engineering specification and detailed drawings to say ASME VIII div one or two and a third party approval of your design, say Lloyds, ABS TuV PVHO you should be able to use a local approved welding/fabrication shop. The shop would have to be approved with the above, submit welding procedures and qualifications and be able to manipulate, (turn roll handle) the size of vessel your after.
Normally apx 10 drawings and 20 page technical specification.

During main component fabrication as they are done all main welds need x ray, before they are attached to the next componant, heads and nozzels need dye pen, the innner lock seam needs ultrasonic testing all from a third party inspection house. After complete assy a hydrostatic test 1 hour each separate lock including the medical lock. The viewports are normally to a code Pressure Vessal Human Occupancy, and have there own certification.

Whilst it is quite possible to use a local coded welding shop for fabrication of your design. the problems they will face will be the door mechanism, safety interlocks on the medical/food lock, view ports and fitting out. Shot blasting is to SA2.5 but be careful with the type of paint used inside.

The small lighweight 180FSW (55MSW) "fly away" chambers used on small craft, take two people, use very little gas and can handle oxy/helium 50/50 mixtures that will reduce the TTUP and the stored gas used in the chamber by hours!

Pics of three types enclosed 50MSW, 100MSW and 250MSW

Is that middle chamber the one at Johnson's NBL?

 

[cool_hardware52]

if that's not fast enough I add gas to the ole drysuit. Last time I was able to exit the water completely and land myself and the double 130s four steps up the swim ladder and one easy stride from the deck.(

Do you have any video?

Tobin

 

[RichLockyer]

Ok, I've got several thousand hours on or in a deco chamber

Wow.
DAN must dread getting your renewal check every year.
Have you ever considered using Nitrox, or a smaller tank?

 

[Seabear70]

Wow.
DAN must dread getting your renewal check every year.
Have you ever considered using Nitrox, or a smaller tank?

LOL

I've never actually been a member of DAN...

I was a commercial diver for a numer of years, and I keep my hand in doing SAR and acting as a safety diver. :scubadive

 

[tekdive007]

Building a hyperbaric chamber is not a difficult task if you are a qualified engineer, boilermaker, pipe and tube fitter, Oxygen technician, with hyperbaric expereince...

Hyperbaric Chambers can be very simple to build and opperate however you need to have the correct training to do both becasue undertakin either construction or operation can be very dangerous if you do not know what you are doing. If you have to ask where to get the plans for one then you are most likely not quailfied either to fabricate, construct, plumb, or operate the device you are going to attempt to build.

Without the proper training and knowledge you will most likely die, kill the people you put in the chamber, start a large fire which will probably result in an explosion of some kind.

You could reference the NFPA, ASME PHVO, or UHMS for more information on hyperbaric chambers. But don't build one, buy one, or operate one unless you have been properly trained. Accidents can occure extremely easily with catastrauphic results. Reference the NBDHMT for information about training.

Does anyone on board know how is a deco chamber are built?What are the main things needed?
or
Does anyone have the link of:
How to make a deco chamber?
Thanks