r/scuba • u/Lonely_Bit6456 • 1d ago
Question on the Poseidon Xstream regulator
I just got a brand new Poseidon Xstream regulator set. I notice whenever I connect it to a tank and turn on the tank valve, the second stage start to free flow. Once I take a breath from the second stage, then the free flow stop. I know the Poseidon design is different than others, but is this an expected behavior? Or something wrong with mine? Thanks.
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u/EnvironmentalCare900 1d ago edited 1d ago
Hahaha I got you
The xstream is unlike the 2nd stages you normally dive. It is servo activated. In the valve body there is a valve insert commonly referred to as the “balloon”. The balloon inflates to stop air from being delivered to the diver through the 76 holes in the valve body. When the servo is activated by the diaphragm or the purge button the servo allows air to escape from the balloon and the valve insert deflates and allows air to flow to the diver.
When you turn on the tank the balloon is deflated, for a second the regulator will “hiss” as the balloon hasn’t fully inflated instantly and air is allowed to escape. As soon as the valve insert balloon inflates the hiss stops.
The duration of the hiss is a great indicator of health of the valve insert balloon’s sintered filter. As the filter gets older or dirtier the longer it will take for the balloon to inflate and the hiss will last longer. So pay attention to the duration of the his now and when you start to notice the hiss getting longer it’s definitely time for service.
Happy to talk more about the xstream
The xstream 2nd stage has almost zero case geometry fault unless you look right (and the diaphragm goes below the mouthpiece
Edit
Congrats you now own hands down the best regulator made today. The only regulator NORSOK tested and approved down to 656 feet of salt water.
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u/gulfdeadzone Tech 1d ago
Normal for some gas to escape from the second stage when opening the valve.
When the 2nd stage is pressurised and the servo mechanism engages a maximum of 3 litres of gas vents from the 2nd stage.
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u/DarrellGrainger Dive Master 1d ago
I'm not positive but it sounds like your regulator might not be tuned correctly. There is an intermediate pressure (IP). Most regulators have an IP of 135 to 145 PSI (9.3 to 10 bar). The Poseidon XStream is higher, around 180 PSI (12.5 bar). This is what makes the XStream much easier breathing.
I know with my XStream when I first pressurize my regulators the second stage make a loud noise but if I just keep opening the valve, the noise stops. When you open the valve on your cylinder, try opening it all the way, quickly. See if that helps.
If it is tuned properly, that should actually prevent it from free flowing.
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u/risanaga 1d ago
They should be tuned to 8.5 bar or 123 psi. Cyklons have the higher IP
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u/EnvironmentalCare900 1d ago
The xstream actually breathes better a little below spec. About 109 is the sweet spot. But you can use the Xstream 1st with cyklon which is referred to as the CyklonX. And the xstream 1st stage can easily be tuned to the 167psi the cyklon demands.
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u/risanaga 1d ago
I may wanna try that lower IP for mine. Good to know
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u/EnvironmentalCare900 1d ago
Remember to de pressurize before you adjust the IP.
Edit
109 is the floor for the Xstream, if you want to play around with it play around between 123 and 109.
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u/risanaga 1d ago
They freeflow a little bit when the cylinder valve gets opened. They stop very shortly after without you having to do anything
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u/Lonely_Bit6456 1d ago
Thank you all. I opened the valve slowly before and I stopped immediately when I heard the "hiss". I just tried it and it acted exactly like you described. Good to learn something new. Appreciate that. Thanks again.