home made dsv

seeboth · 14th March 2008, 22:39

I just have to chime in here, about using pvc for a rebreather.

As an industrial designer i've gone through many classes specifically on materials and in what applications they are acceptable. There are reasons why vinyls such as pvc (poly vinyl chloride) are being phased out in many consumer products. they all off gas and in pretty high amounts. There isnt a great deal of research done on the effects of this that I know of, but Ill look into it more. (I was satisfied with avoiding it all together)

With other products out there such as ABS plastic (delrin is a brand name for ABS), which is much more stable I would rather avoid anything that is known to off gas. This is actually the only reason I chose not to get the Pelagian, it uses a pvc canister.

Even the Polycarbonate used in the popular nalgene bottles has been under fire lately for leaching chemicals into the water stored in it.

While I know every plastic will off-gas something, I would rather not use a plastic as volatile as pvc in a high O2 pressure environment where off-gassing is even more prevalent.

Sorry for the hijack, other than the material choice I think that making your own DSV is very reasonable, and I currently have a block of ABS sitting next to my lathe waiting to become one. To be fair though the plastic shop in town has a deal where it $25 for all you can carry out of their scrap room, which helps me stay on budget.

- Al

seeboth · 14th March 2008, 22:42

Quote: (Originally Posted by Tautaz)

The matter for me is: don't we use drinkable water coming thru PVC pipes?

water and air can allow things to off gas very differently, and pressure changes can have a big effect too

cool_hardware52 · 15th March 2008, 01:20

Quote: (Originally Posted by seeboth)

I just have to chime in here, about using pvc for a rebreather.

As an industrial designer i've gone through many classes specifically on materials and in what applications they are acceptable. There are reasons why vinyls such as pvc (poly vinyl chloride) are being phased out in many consumer products. they all off gas and in pretty high amounts. There isnt a great deal of research done on the effects of this that I know of, but Ill look into it more. (I was satisfied with avoiding it all together)

With other products out there such as ABS plastic (delrin is a brand name for ABS)

Can you get your money back for those material classes?

Delrin is Dupont's trade name for Acetal. DuPont Delrin® acetal resin

ABS is an acronym for Acrylonitrile Butadiene Styrene. Acrylonitrile Butadiene Styrene (ABS) Plastic Resin

Tobin

Tino de Rijk · 15th March 2008, 11:30

Absolutely bloody brilliant!! I thought only the Dutch could be so blunt & rude.... Have been standing too loooong with my finger in a dike, I guess....

tino.

Quote: (Originally Posted by Dave Sutton)

You really need to post a "swallow coffee before opening this link" warning... I hate cleaning off my computer....

Dave

.

14th March 2008, 22:39	#51 (permalink)
seeboth RBW Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jan 2008 Location: Wisconsin, United States Posts: 52	Re: home made dsv I just have to chime in here, about using pvc for a rebreather. As an industrial designer i've gone through many classes specifically on materials and in what applications they are acceptable. There are reasons why vinyls such as pvc (poly vinyl chloride) are being phased out in many consumer products. they all off gas and in pretty high amounts. There isnt a great deal of research done on the effects of this that I know of, but Ill look into it more. (I was satisfied with avoiding it all together) With other products out there such as ABS plastic (delrin is a brand name for ABS), which is much more stable I would rather avoid anything that is known to off gas. This is actually the only reason I chose not to get the Pelagian, it uses a pvc canister. Even the Polycarbonate used in the popular nalgene bottles has been under fire lately for leaching chemicals into the water stored in it. While I know every plastic will off-gas something, I would rather not use a plastic as volatile as pvc in a high O2 pressure environment where off-gassing is even more prevalent. Sorry for the hijack, other than the material choice I think that making your own DSV is very reasonable, and I currently have a block of ABS sitting next to my lathe waiting to become one. To be fair though the plastic shop in town has a deal where it $25 for all you can carry out of their scrap room, which helps me stay on budget. - Al __________________ Northwoods Megalodon
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14th March 2008, 22:42	#52 (permalink)
seeboth RBW Member Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Jan 2008 Location: Wisconsin, United States Posts: 52	Re: home made dsv Quote: (Originally Posted by Tautaz) The matter for me is: don't we use drinkable water coming thru PVC pipes? water and air can allow things to off gas very differently, and pressure changes can have a big effect too __________________ Northwoods Megalodon
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15th March 2008, 01:20	#53 (permalink)
cool_hardware52 RBW Member Current Rebreather/s: Not Bought Yet Other Rebreather/s: Not Bought Yet Join Date: Mar 2005 Location: SoCal USA Posts: 399	Re: home made dsv Quote: (Originally Posted by seeboth) I just have to chime in here, about using pvc for a rebreather. As an industrial designer i've gone through many classes specifically on materials and in what applications they are acceptable. There are reasons why vinyls such as pvc (poly vinyl chloride) are being phased out in many consumer products. they all off gas and in pretty high amounts. There isnt a great deal of research done on the effects of this that I know of, but Ill look into it more. (I was satisfied with avoiding it all together) With other products out there such as ABS plastic (delrin is a brand name for ABS) Can you get your money back for those material classes? Delrin is Dupont's trade name for Acetal. DuPont Delrin® acetal resin ABS is an acronym for Acrylonitrile Butadiene Styrene. Acrylonitrile Butadiene Styrene (ABS) Plastic Resin Tobin __________________ www.deepseasupply.com
(Online)

15th March 2008, 11:30	#54 (permalink)
Tino de Rijk Old, maybe one day wise Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Evolution Join Date: Mar 2006 Location: Amsterdam Posts: 375	Re: home made dsv Absolutely bloody brilliant!! I thought only the Dutch could be so blunt & rude.... Have been standing too loooong with my finger in a dike, I guess.... tino. Quote: (Originally Posted by Dave Sutton) You really need to post a "swallow coffee before opening this link" warning... I hate cleaning off my computer.... Dave .
(Offline)

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