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Post by vintagefrank on Sept 28, 2008 22:50:43 GMT -8
Dear Friends,
want to power up my trieste. What do you consider to be the best methods to improve the (right now) not so good breathing caracteristics?
Where can I get a silicone diaphragm?
thanks in advance
frank
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Post by JES on Sept 29, 2008 3:32:26 GMT -8
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Post by SeaRat on Sept 29, 2008 7:42:56 GMT -8
Frank,
There are three things you can do for the Trieste to make it an excellent breathing reguator. While I was unaware of the silicone diaphragm being available, I would hartily endorse this upgrade. I made my own diaphragm, and this measure alone made a large amount of difference. The original diaphragm had a built-in problem--in order to depress it, you needed at least a 1 inch suction pressure. The diaphragm had a molded-in "set" which required increased effort to depress the diaphragm. So this will dramatically affect the breathing.
Second, the LP nozzle is not always pointed directly down the intake hose. The set screw which keeps the nozzle from moving has too much latitude in it, and will allow the nozzle to move. So check it and make sure that it is aimed correctly.
The nozzle itself has a few problems. Set the interstage pressure, then unscrew the nozzle until you have a leak, and screw it in one-half turn. Unlike the RAM, the Trieste has the ability to adjust the nozzle for spring differentials. The second problem of the nozzle is that it lets too much air into the case. I had mine modified to block off outlet. I don't recall exactly what I did now, but I have documented it on these threads. Search for "Ratliff Trieste" or "Searat Trieste" and see what you find.
The final modification, because the increased venturi allowed "blow-by" through the hose system, was to put a baffle plate in the mouthpiece, like what was designed for the Healthways SCUBA Delux regulator.
If you do all these, you will have a very well-performing regulator.
John
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Post by luis on Sept 29, 2008 8:08:51 GMT -8
Unlike the RAM, the Trieste has the ability to adjust the nozzle for spring differentials. John I do that all the time for all of my RAM (including Phoenix RAM). The only difference is that it has to be adjusted in 120 degree increments of rotation rather than 180 degrees for the Trieste. It does a decent job of adjusting the second stage spring compression (and therefore the 2nd stage free flow pressure). My procedure with the RAM is a bit tricky because of the keepers in the horse shoe supports, but I can do it pretty quickly. The final fine tuning adjustment is with the IP to be about 15 psi below 2nd stage free flow. But all my second stages are set to free flow around 155 to 165 psi roughly. A similar procedure should also work for the Trieste, but I have only played a bit with one. Either way should accomplish the same purpose of lowering the initial cracking inhalation suction (also with lower suction requirements, the venturi should also be more effective). I just feel that a final adjustment using the IP adjustment can be more precise, since the 2nd stage adjustment are limited to discrete increments in order to properly align the venturi opening. You are just balancing the spring force against the pneumatic force. Note: With the new Phoenix Mod II the IP stays a lot more constant through the breathing cycle so I am using a lower IP (the IP recovers much quicker, back to the set pressure). |
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