Newly Designed Diaphragms for Trieste Regs - James and AntiqueDiver have been working on a better diaphragm design for the Trieste Double Hose Regulator. James is producing it and AntiqueDiver has been testing it. Here's what it offers:
1. Easier breathing - It's not a dome design so it compresses easier. 2. It's Made of Silicone - More sensitive and long lasting. 3. Sized correctly to fit the ridges in the Trieste cans... Easier to install and more secure.
They're finished with development and testing and are offering these for sale now. I got my order in this morning.
First Impressions - Dive Report - I finally got to try my new Trieste Diaphragm underwater and I'm pleased to report, it's a huge success. Rich and I went to the public pool last Sunday... Max Depth 12 feet ... To do a comparison test between my new diaphragm equipped Trieste and three other double hose regulators. - First is my new diaphragm Trieste... I dove it like I was just going diving with any of my DH regulators. My impressions are as follows. Very smooth and effortless inhaling. Actually quieter than expected. I swam a couple of underwater laps while kicking hard with my fins and never felt out of breath or any excess breathing effort. I don't have instruments to measure but the ease of breathing with the new diaphragm puts this regulator into the realm of a regular go-to Double Hose Regulator like most of my others - Second was Rich's Trieste which was re-built by Greg Barlow and with the Dome Shaped replacement diaphragm that has been the only option until now. This regulator felt fine for the first 5-10 breaths. But as the dive progressed I could tell it was requiring significantly more effort to inhale. And it was more and more noticeable as my breathing muscles got more fatigued. Rich calls it a "Wall Hanger" because of the excessive breqathing effort. I think we'll put a new James and Bill Diaphragm in it and turn it into a breather. - 3rd was my Voit Navy... I figured that would be good to compare with these two Voits. My NAVY is tuned up and breathes super nice. And I think my Trieste with the new diaphragm was very close to the same breathing effort. I know it was not BETTER than the Navy but it was just as easy or awfully close. - 4th was my Snark III... This one was a little difficult to judge. The Snark III was making alot of airflow noise like a Mistral and behaving a little erratic... like it wanted to free flow if I took too fast of a breath. By comparison, the New Diaphragm Trieste breathed quieter and smoother. Probably not a fair comparison with the Snark III acting strange as it was. - 5th... Along with the new diaphragm, I ordered a 2-piece band clamp. This clamp makes it much easier to install a new diaphragm nice a straight and centered... Something very difficult with the original 1-piece band clamp.
Last Edit: Feb 16, 2022 12:05:17 GMT -8 by surflung
Short version: With a new style Scuba Museum duckbill, and this new diaphragm, a failed intake non-return in your mouthpiece can cause impeded or blocked exhale. It is not a major safety issue, in that you would the exhale around the mouthpiece. In the meantime, the old style flat duckbill does not have this interaction. I will work on a solution to this unforeseen failure mode, and update as I go.
Longer version: In Surflung's installation and testing process he experienced an issue that neither I nor Bill could reproduce... on exhale he would get unusual resistance up to and including complete blockage. Some troubleshooting later, replacement of his intake non-return solved the problem. Both Bill and I set out to recreate the issue ourselves and couldn't.... but we did notice Surflung has the new, formed, Duckbill from the scuba museum while bill and I both have old style flat Duckbills. I now have a formed Duckbill on hand, and can recreate the exhaust lock up (only by removing my intake wagon wheel). I will be working on a solution to eliminate this failure mode, and will advise as I go. Regardless of what it takes, I'll get the fix to everyone who has one once it is sorted.