Regulator free flow and near panic

[John C. Ratliff]

If i recall correctly, IP was set on the higher end of the range, the really cold temps combined with inflating wing/drysuit while taking a breath in caused to free flow, once the IP was lowered, I haven't had any issues since, even in 0 degrees. I tend to not bite down too hard on my mouthpiece, just enough to keep it from falling out.

Okay, that sounds like a freeze-up situation. Now it makes sense.

SeaRat

 

[John C. Ratliff]

Could someone explain how one can lower the IP ? Is that something that can be done easily ?

Thanks!

It depends; it's pretty easy with a diaphragm first stage, and more difficult to impossible with a piston first stage, to lower the IP.

With a diaphragm first stage, the regulator usually has a cap that can either tighten (for higher IP), or loosen (for lower IP) this main spring's tension. Sometimes it's simply by using a screwdriver, and sometimes it's an Allen wrench adjustment.

With a piston regulator, the IP can usually be increased by adding a thin stainless steel washer to the bottom of the area where the piston's spring rests. But that only increases the IP. If washers are already there, then one or more can be removed. Usually a washer adds about 2.5 psi to the IP. But if there are no washers to subtract, then lessening the IP is problematical.

Some of the more advanced piston designs allow the piston's spring tension to be adjusted, but usually there is a special tool needed to get to that area, and so this is something that the LDS should be doing. (Actually this also applies to the adding of a washer, as getting to that area involves some disassembly of the first stage.)

SeaRat

 

[PR_SMITH]

If you are diving a long hose, then the backup reg is often bungeed around your neck. That would have made is almost foolproof to locate the second reg, saved yourself some stress and avoided the need for a donation.
Practice long hose donations with an experienced buddy or an instructor and you'll do fine.

I always like to get used to new gear setups in a pool or easy access shore dive. Jumping off a boat with too much new gear, as you acknowledged, isn't great.

 

[Wagiman]

Thanks for the explanation Searat. So you need to know what you are doing

 

[James79]

Thanks for the explanation Searat. So you need to know what you are doing

To add to what @John C. Ratliff said, after adjusting the IP, second stages will need to be re-tuned to match. Not re-tuning after lowering the IP some won't generally render them unserviceable, but will effect the breathing characteristics (generally for the worse).

Respectfully,

James

 

[John C. Ratliff]

If you are diving a long hose, then the backup reg is often bungeed around your neck. That would have made is almost foolproof to locate the second reg, saved yourself some stress and avoided the need for a donation.
Practice long hose donations with an experienced buddy or an instructor and you'll do fine.

I always like to get used to new gear setups in a pool or easy access shore dive. Jumping off a boat with too much new gear, as you acknowledged, isn't great.

I generally agree with you about this, but a free flowing second stage due to icing would not be solved by switching to the second regulator bungeed around the diver's neck. Why? Well, because a freeze-up like this probably gets worse as the air is expelled (more ice develops due to cooling from the exhausted air), and therefore the tank's pressure would be exhausted soon. Fairly soon, he would have needed a donation from his buddy.

SeaRat

 

[grf88]

Slinging a pony can remove the drama from cold water diving.

 

[John C. Ratliff]

Slinging a pony can remove the drama from cold water diving.

So can using a double hose regulator.

SeaRat

 

[lexvil]

Two piston Regs that I can think of off the top of my head with an easily adjustable IP and the SP mk25 and 21, unlike a diaphragm they need to be adjusted with pressure off.

 

[Jcp2]

Two piston Regs that I can think of off the top of my head with an easily adjustable IP and the SP mk25 and 21, unlike a diaphragm they need to be adjusted with pressure off.

USD Aquarius, but needs LP splitters to get LP ports for modern diving.