2nd stage issue?

[amclaughlin200]

A question for the reg techs out there..

Recently I had a hollis regulator serviced and everything seems fine except if I turn both 2nd stage adjustments(venturi and knob) to the full + it will immediately freeflow from the 2nd stage after purging. When you pressurize the reg even with both knobs turned to "+" it's fine but it freeflows immediately upon purging. Normally if I continue purging it a few times it will go to a smaller leak than a full on freeflow.

If the adjustment knobs are turned back then I don't seem to have any issues when purging.

I don't dive the regs on full "+" but this is a friend's regulator and she is a bit of a nervous diver and always wants to turn all the knobs on high. Over time I'd like to get her out of this habit but it still led me to question the service of the regulator because I figured even if the knobs are on high it shouldn't full on free flow right?

Please don't tell me to take it to a dive shop because I'm in a remote area right now and the closest dive shop is multiple flights away. Thanks.

 

[BoltSnap]

I think that it is working as it should. When the knob is out all the way and the venturi is on and you press the purge button it will let air out and will continue to do that until you put your finger/thumb on the mouthpiece opening to stop the venturi effect and the freeflow should stop. It is supposed to do that by design.

When you are diving, you should have the adjustment knob on full +, open all the way out, and venturi on. As long as the mouthpiece is in your mouth, adjustment knob should be all the way out and venturi on full on. The only time you turn the knob back is if there is air leak when you are breathing from the second stage. You turn the knob back just to stop the leak. When the regulator mouthpiece is out of your mouth, the knob should be turned in and venturi off.

 

[BoltSnap]

I don't dive the regs on full "+" but this is a friend's regulator and she is a bit of a nervous diver and always wants to turn all the knobs on high.

She is doing it right, you are doing it not so right.

Over time I'd like to get her out of this habit

Don't, she is doing it right.

it still led me to question the service of the regulator

It appears to be doing what it was designed to do, no issues.

 

[runsongas]

as long as it doesn't go into an uncontrolled freeflow even when in your mouth, then its fine. its also why you don't leave the predive/venturi on for your backup/octo when not in use.

 

[Pbdiver84]

A question for the reg techs out there..

Recently I had a hollis regulator serviced and everything seems fine except if I turn both 2nd stage adjustments(venturi and knob) to the full + it will immediately freeflow from the 2nd stage after purging. When you pressurize the reg even with both knobs turned to "+" it's fine but it freeflows immediately upon purging. Normally if I continue purging it a few times it will go to a smaller leak than a full on freeflow.

If the adjustment knobs are turned back then I don't seem to have any issues when purging.

I don't dive the regs on full "+" but this is a friend's regulator and she is a bit of a nervous diver and always wants to turn all the knobs on high. Over time I'd like to get her out of this habit but it still led me to question the service of the regulator because I figured even if the knobs are on high it shouldn't full on free flow right?

Please don't tell me to take it to a dive shop because I'm in a remote area right now and the closest dive shop is multiple flights away. Thanks.

So it’s free flowing at the surface after purging it? You have a very lightly tuned regulator… increased pressure at depth or obstructing the mouthpiece opening will prevent or stop the flow.

Nothing wrong with it unless you can’t stop the free flow with increased pressure

 

[happy-diver]

Only times I purge is when depressurising regs or when I want to give myself a purge underwater

 

[Nemrod]

A question for the reg techs out there..

Recently I had a hollis regulator serviced and everything seems fine except if I turn both 2nd stage adjustments(venturi and knob) to the full + it will immediately freeflow from the 2nd stage after purging. When you pressurize the reg even with both knobs turned to "+" it's fine but it freeflows immediately upon purging. Normally if I continue purging it a few times it will go to a smaller leak than a full on freeflow.

If the adjustment knobs are turned back then I don't seem to have any issues when purging.

I don't dive the regs on full "+" but this is a friend's regulator and she is a bit of a nervous diver and always wants to turn all the knobs on high. Over time I'd like to get her out of this habit but it still led me to question the service of the regulator because I figured even if the knobs are on high it shouldn't full on free flow right?

Please don't tell me to take it to a dive shop because I'm in a remote area right now and the closest dive shop is multiple flights away. Thanks.

A second stage should, with the Venturi set to maximum, free flow upon purging. That is a function test in the Scubapro SM and is correct. The regulator should NOT free flow when the Venturi is set to minimum and purged.

Your regulator may not be a Scubapro but there will be similar instructions for regulators with an adjustable Venturi or Dive/Pre-dive switch, read the bottom series of bullets, this for the SP G250V:



Edit to add, some months back there was a big dust up over a fellow using the word "crisply" in regards to first stage lock up, now here Scubapro uses that adjective for stoppage of second stage flow. I thought he and the adjective convey what is meant quite crisply, just me I guess.

Second edit to add, there is no reason to be turning the VIVA control towards Minimum during use to increase WOB nor is there good reason with the exception of swimming into current and perhaps another thing or two, to roll the adjustment knob to increase breathing resistance. The VIVA should be full on or if it is labeled a Dive/Pre-dive it should be in Dive during use and the adjustment knob should be full out (or out until leakage is detected for hot tuned seconds). An octopus or secondary would of course be set to Pre-dive or Minimum VIVA and/or roll in a little resistance on the adjustment knob to prevent nuisance free flows.

 

[amclaughlin200]

I think that it is working as it should. When the knob is out all the way and the venturi is on and you press the purge button it will let air out and will continue to do that until you put your finger/thumb on the mouthpiece opening to stop the venturi effect and the freeflow should stop. It is supposed to do that by design.

When you are diving, you should have the adjustment knob on full +, open all the way out, and venturi on. As long as the mouthpiece is in your mouth, adjustment knob should be all the way out and venturi on full on. The only time you turn the knob back is if there is air leak when you are breathing from the second stage. You turn the knob back just to stop the leak. When the regulator mouthpiece is out of your mouth, the knob should be turned in and

I think that it is working as it should. When the knob is out all the way and the venturi is on and you press the purge button it will let air out and will continue to do that until you put your finger/thumb on the mouthpiece opening to stop the venturi effect and the freeflow should stop. It is supposed to do that by design.

When you are diving, you should have the adjustment knob on full +, open all the way out, and venturi on. As long as the mouthpiece is in your mouth, adjustment knob should be all the way out and venturi on full on. The only time you turn the knob back is if there is air leak when you are breathing from the second stage. You turn the knob back just to stop the leak. When the regulator mouthpiece is out of your mouth, the knob should be turned in and venturi off.

Thanks for the advice. What is the reason for not diving with the adjustments partially closed? I much prefer them closer to low than high. You're telling me this is a 100% wrong way of diving? It has nothing to do with diver preference?

 

[happy-diver]

this is a friend's regulator and she is a bit of a nervous diver and always wants to turn all the knobs on high.

Yes it's about diver preference

https://www.hollis.com/media/wysiwyg/HO/manuals/Hollis_Reg_Owners_manual_HO.01.05.0001_10-12-2017.pdf

https://www.scubadoctor.com.au/downloads/regulator-manuals/Hollis_Regulators.pdf

 

[steinbil]

Thanks for the advice. What is the reason for not diving with the adjustments partially closed? I much prefer them closer to low than high. You're telling me this is a 100% wrong way of diving? It has nothing to do with diver preference?

Less work of breathing means breathing muscles are working less, less energy spent, and a lower gas consumption. High WOB can lead to deficient ventilation, causing a CO2 build up, so depending on your depth, the density of the gas and your workload, you should be careful of artificially raising the WOB.

In general, lower WOB is better.