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Post by snark3 on Jun 4, 2021 14:55:39 GMT -8
JB is looking for things to keep conversation going here so I thought I'd start one. I recently built a manometer to check some of my regs. I did this more out of curiosity tan anything. My first "victim" was a recently rebuilt New England Divers rebranded Hydro Twin 2. I have 2 books on regs Vance Harlow's SCUBA Regulator maintenance and repair, and Peter Wolfinger's Regulator savvy. One of them says "modern high performance regs will have a cracking effort of 1- 1.5" of water while older regs may be as high as 3-4". My 50 year old Sportsways must be a high performance reg because it was cracking between 5/8 and 3/4" of water.
What do you guys look for as a cracking effort when you do your regs?
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Post by vance on Jun 4, 2021 15:40:24 GMT -8
Charlie just sent me an old one he had. I've yet to set it up, but I'm curious how my regs will perform. This should give up some great information on the efficiency of my mods.
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Post by SeaRat on Jun 4, 2021 18:01:08 GMT -8
My double hose regulators typically crack at about 1/2 inch (Trieste II, Royal Aquamaster, Sportsways Hydro-Twin II, and Dacor Clipper). My very old double hose regulators will crack at 1-3 inches (Dacor R-2, R-3, and Healthways Scuba, Scuba Deluxe). My Aquamatic was a very hard breather, at about 3 inches (untested; I used it only in a pool). Any of my regulators which have a cracking effort over one inch of water, I won’t take into open water unless I’m simply looking at how it breaths. The DA Aqualung (Green Label) is one that I hesitate to take into open water due to high cracking effort and high breathing resistance on the inhalation side. But, it is the quietest regulator that I have. My Overpressure Breathing regulator, and my Mistral, have a high cracking effort (probably 1.5-2 inches of water on a full tank), but breathe like a dream at about 500 psi.
John
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Post by herman on Jun 5, 2021 2:11:22 GMT -8
Are you doubling the deflection of the water column? I missed this important bit of info when I first built one. The measurement is the amount the column drops on one side plus the amount (the same) it rises in the other column or 2X the movement in one column.
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Post by nikeajax on Jun 5, 2021 7:46:42 GMT -8
Skip, did you make a special mouthpiece for this?
Thanks for that heads up Herman! So, when you do this you're just watching/eyeballing where it goes to when you take a breath, is that correct?
JB
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Post by herman on Jun 5, 2021 8:01:11 GMT -8
Correct, as you inhale/exhale (you can check exhaust pressure as well) you take the reading off of the scale on one side, does not matter which, then double it. Or if you are so inclined, make a new scale where a 1 IWC is 2 measaured inches and read just it. I assume we are talking about a U tube manometer with water in it (food coloring helps make it easier to read), some call magnehelic gauges "manometers", those are read normally.
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Post by cnotthoff on Jun 5, 2021 8:37:14 GMT -8
When I built this, I considered printing a scale that would show cracking resistance in a measurement on one side. I opted for using a standard scale that requires the user to do the math. In use, I would slide the scale to align a inch mark with the top of the undeflected water column. If the water column drops 3/4" on one side while testing cracking resistance, the proper measurement is 1.5 inches of water. I'm sure Phil can figure that out. I experimented with food coloring in the water to make it easier to use. I found that stained the tube making it harder to read. I had to periodically flush the tube with some bleach to kill the things that started to grow in it. It worked well for many years, until I sprang for a magnehelic. Good Dives, Charlie vintagescuba.proboards.com/thread/5361/manometer
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Post by snark3 on Jun 5, 2021 8:42:08 GMT -8
Are you doubling the deflection of the water column? I missed this important bit of info when I first built one. The measurement is the amount the column drops on one side plus the amount (the same) it rises in the other column or 2X the movement in one column. Herman- I am not. If doubled it would be about 1.25 to 1.50. still fairly good I think.
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Post by snark3 on Jun 5, 2021 8:44:41 GMT -8
Skip, did you make a special mouthpiece for this? Thanks for that heads up Herman! So, when you do this you're just watching/eyeballing where it goes to when you take a breath, is that correct? JB JB- I did, I took an old rubber USD mouthpiece and put a hole through the front then attached a fitting to go to the 1/4"tubing. Yes just eyeballing it as I take a breath.
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Post by SeaRat on Jun 5, 2021 11:09:44 GMT -8
I built one of those years ago, using the same plastic tubing. But I left the tubing long enough that I could easily get it into my mouth. I also placed marks to one side on the scale of 1/2 inch = 1 inch; for instance, at 1/2 inch on one side, I wrote 1 inch. At 1 inch, I wrote 2 inches. That way I didn't have to do math on it. This worked very well, and I found that I could put the closed end of the tube into my mouth beside my lip, and seal it with my lip; in this way I could evaluate any regulator with a mouthpiece.
John
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