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Re: [PSUBS-MAILIST] Submadman HP Air Muffler

Jay,
The plastic piping has to many holes in it to build up any real pressure over the external pressure, and it absorbs sound vibrations much better then metal piping, and is far cheaper then SS or other corrosion resistant metal piping.  The towel is 100 percent cotton, like the clothing we wear in the chamber. We use a BIBS mask set up to breath the O2, so the chamber doesn't need to be filled with O2. Which would be cost prohibitive and far more dangerous. 
 
With the O2 system turned off, I've had candles going in that chamber as I increased the pressure, to see how the flame is effected,  It was hard to tell, since the wax was getting hotter over time. But the measurements make it look like at 2 ATM the flame was about a third higher.  The percentage of O2 was of course the same.  Will do more with that later.
 
Cheers
Brent

Sent: Sunday, August 09, 2009 5:34 AM
Subject: RE: [PSUBS-MAILIST] Submadman HP Air Muffler

Brent,

If you look at the spec sheets for PVC piping and fittings you will find a warning not to be used for air service.  With an inadvertent blockage, the PVC can be quickly over-pressurized and shatter into lethal shrapnel shards.  Better to use metal piping for your application.  Is the towel flame retardant?  And with additional thought there is a fire issue using PVC.

R/Jay

 

 

Resepectfully,

Jay K. Jeffries

Andros Is., Bahamas

 

Save the whales, collect the whole set.

 

 

 

From: owner-personal_submersibles@psubs.org [mailto:owner-personal_submersibles@psubs.org] On Behalf Of Brent Hartwig
Sent: Sunday, August 09, 2009 3:28 AM
To: PSUBSorg
Subject: [PSUBS-MAILIST] Submadman HP Air Muffler

 



We needed a better air muffler for the incoming air for are hyperbaric chambers, and I had a idea I had done some test runs with at home in the shop that seemed to be in the right direction.
 
This is what we ended up with. Basically a PVC union to make it easy to remove, a good thick bath towel, and the rest ABS plastic piping.  We drilled a very large number of holes into the second tube that is covered by the towel, and then a few larger ones on the large cap that covers the end of the large tube, so it won't launch it's self.  By using a secondary regulator, to keep the pressure down, that is going thru the cracked valve in the chamber, and the new muffler, we were able to seriously bring the hiss decibel level down.  Having a valve outside the chamber that you could operate remotely, or have some one outside the tank open, that is some distance away, and the air coming out of it going thru a hose, would be a good upgrade to reduce noise.
 
http://cid-5085d10eb6afe47c.skydrive.live.com/browse.aspx/Submadman%20HP%20Air%20Muffler
 
We have some more ideas to try with this basic design, but have been happy with the results over the last few months of using it.

Regards,
Szybowski