Fine tuning your reg on location

[ben_wilson3301]

I was just wondering how you fine tune your reg when your on location? I have the scubapro G250V and want get it set just right. I have never dove with a reg that was adjustable before and am really looking forward to feeling the difference.

 

[Bubbletrubble]

It all depends. A majority of my dives are shore dives where I have to contend with surf. For such entries, it's helpful to detune my second stage regulators (primary and backup) to guard against unintentional freeflow at the surface. I turn the inhalation adjustment knob in (to increase the cracking pressure), and I switch the Venturi knob to (-). Just before I do my initial descent, I'll open up the inhalation adjustment knob (to decrease cracking pressure) on my primary reg. During the initial phases of the dive, I'll switch from my primary to the backup reg to verify that the reg works properly underwater.

I tune my second stages at home prior to arriving at the dive site to freeflow slightly when the inhalation adjustment knob is turned out/fully open. Before setting the lever height on the second stage, I verify that the first stage is delivering the desired intermediate pressure.

 

[herman]

Assuming the entry is fairly easy, I adjust it out until it barely freeflows then in just enough to stop the freeflow. Mine are preset to barely freeflow when fully open as well. If a shop tech tuned yours, odds are it is set to NOT freeflow even when fully open per service manual. In that case, I would open it fully, just be aware if you also have the venturi set to max it may force feed you air and it WILL freeflow violently if you bump the purge.

 

[Dirty-Dog]

We use the Mk11/G250V as well. Ours are tuned to just barely freeflow when fully opened. Just turn the adjustment knob in until it stops freeflowing.

 

[Thalassamania]

The first thing that you have to understand is that it is unlikely that you will feel any difference between your regulator and a bhigh quality non-adjutable. You see, when properly set up, with the adjustor fully open, the regualator should breathe as well as it's ever going to. The adjustor doesn't make the regulator breathe better, it just permits you to make it breathe worse under conditions where you are concerned that it might freeflow.

 

[herman]

The first thing that you have to understand is that it is unlikely that you will feel any difference between your regulator and a bhigh quality non-adjutable. You see, when properly set up, with the adjustor fully open, the regualator should breathe as well as it's ever going to. The adjustor doesn't make the regulator breathe better, it just permits you to make it breathe worse under conditions where you are concerned that it might freeflow.

I agree IF the tech sets the reg up just below the freeflow point but most will not and it's not in their best interest to do so because odds are the reg will come back shortly with a customer complaint that is is now freeflowing once the seat takes a set. Most will set the reg to the factory spec which is often 1.25 to 1.5 IWC as opposed to the .5 to .75 that the reg can easily be adjusted to. Granted, most divers can't tell the difference anyway but an adjustable reg allows for the setting of the reg at a lower cracking pressure to satisfy the picky amoung us (me) and still be able to prevent freeflows plus avoiding the return trip to the tech.

 

[ben_wilson3301]

Not sure about the numbers exactly but I want to say I remember him setting it to .8 or .9, somewhere in there. So set the venturi so that it pushes air but doesn't choke you, and the inhalation adjustment to barely free flow and then back it off just enough to quit? Assuming its an easy boat entry.

 

[LeadTurn_SD]

I agree IF the tech sets the reg up just below the freeflow point but most will not and it's not in their best interest to do so because odds are the reg will come back shortly with a customer complaint that is is now freeflowing once the seat takes a set. Most will set the reg to the factory spec which is often 1.25 to 1.5 IWC as opposed to the .5 to .75 that the reg can easily be adjusted to. Granted, most divers can't tell the difference anyway but an adjustable reg allows for the setting of the reg at a lower cracking pressure to satisfy the picky amoung us (me) and still be able to prevent freeflows plus avoiding the return trip to the tech.

Herman,

Can you actually set most "conventional" 2nds that far below 1.0" cracking pressure (or whatever the diaphragm-to-exhaust-valve distance is for that particular 2nd), without getting face-down or head-down free flows?

I honestly don't know (I simply tune my non-adjustables to lowest-end of factory spec), and my adjustables to just a hair above free flow.... but I probably err on the too-conservative side since I'm fairly new at reg tuning.

I guess what I'm thinking is that the average tech will be a bit more conservative with tuning a customer's 2nd, regardless of whether it is adjustable or non-adjustable for the exact reason you stated.... for their "personal" regs, they may set them up "hotter"...

Thanks.

Best wishes.

 

[knowone]

I agree IF the tech sets the reg up just below the freeflow point but most will not and it's not in their best interest to do so because odds are the reg will come back shortly with a customer complaint that is is now freeflowing once the seat takes a set. Most will set the reg to the factory spec which is often 1.25 to 1.5 IWC as opposed to the .5 to .75 that the reg can easily be adjusted to. Granted, most divers can't tell the difference anyway but an adjustable reg allows for the setting of the reg at a lower cracking pressure to satisfy the picky amoung us (me) and still be able to prevent freeflows plus avoiding the return trip to the tech.

See. Thats why you leave the old one in, until it hisses at you and buy air instead.

 

[herman]

Depends on case geometry but yea you can get some of the newer regs pretty low with .5 being the practical limit. They get touchy when you do and the slightest change will cause problems so no tech is going to set a customers that way, esp when the factory is calling for 1.25 or more. 1 IWC is likely the best spot to tune one for yourself if it's not adjustable. Some of the older regs will not tune down that low due to spring, diaphgram and lever designs that just will not allow you to unless you start swapping springs and getting creative. Unless you are doing it as a challenge, it's not worth the effort.

knowone, no offence but your post never make any sence. You might want to try reading them before hitting the post button.