Apeks XTX50 adjustable cracking control question

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aoo

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Location
Philippines
# of dives
200 - 499
Pardon the noob question.

I presently have an Apeks XTX40 second stage reg. It has happened a couple of times that the reg started to freeflow. A slight adjustment by my shop fixed the problem but it was a pain not being able to stop the flow during the dive and while on the boat before the next dive.

I have been told by others that I should have gotten the XTX50 as you can control the flow in case the reg freeflows. I have looked into the specs of both and it seems that the only real difference I can see between the two is that the XTX50 has a feature called "adjustable cracking control".

Is there really such a feature that allows one to make the adjustments to stop a reg from freeflowing and if yes is this the feature?

Hope any of you can help clarify this before I go and buy a new second stage.
 
There is indeed such a feature. On the XTX50 there is a metal knob on the left side of the 2nd stage opposite the hose, which allows you to dial the cracking pressure up and down a bit. Enough to prevent free flows. Was just playing with this feature yesterday - works like a charm.

Henrik
 
There is indeed such a feature. On the XTX50 there is a metal knob on the left side of the 2nd stage opposite the hose, which allows you to dial the cracking pressure up and down a bit. Enough to prevent free flows. Was just playing with this feature yesterday - works like a charm.

Henrik

Hi Henrik,

Thanks for the almost immediate response and the confirmation that such a feature exists. I guess there is nothing left for me to do but to go and buy two of the XTX50's for my wife and I.
 
I would check if there is a way to just upgrade your XTX40. Apeks 2nd stages are nearly identical through the XTX range, so it may be as simple as exchange some of the "innards" to make your XTX40 into an XTX50. Worth checking if it's possible - and of course if the cost makes it worth it ...?

Good luck

Henrik
 
You can just add the knob to the XTX 40... Accessories To isolate that second stage and prevent the continual loss of air.
The venturi control is what you would use to adjust the breathing resistance not the free flow control knob. The free flow knob stops the flow of air completely! It doesn't seem to me that this is what you want.

I have been told by others that I should have gotten the XTX50 as you can control the flow in case the reg freeflows.

Ususally when you first enter the water the change of pressure may cause the reg to free flow, this can be fixed by adjusting the venturi control. Someone may be trying to up sell you since both the 40 and the 50 have the same venturi control.

Wys.
 
Hi Henrik,

Thanks for the almost immediate response and the confirmation that such a feature exists. I guess there is nothing left for me to do but to go and buy two of the XTX50's for my wife and I.

I would consider adding the knob to your XTX 40's before you go and buy new regs. But, if you want to sell one of the XTX 40's send me a pm.

Or, you can do what I do with my Titan LX's and Apeks ATX 40: carry a small allen wrench which fits the allen screw in the side of the second stage. I believe Apeks is a 5mm. Turning this screw does exactly what the knob on the ATX/XTX 50 does, but not so conveniently. Usually, the only time this adjustment is truly necessary, is with a new reg, or one that has been newly serviced. This is because it usually takes a bit of time for the soft seat to be engraved by the hard seat. In "non-adjustable" seconds, most techs allow for this engraving, but some do not (or guess wrong), and a slight free flow develops.
 
There's a switch with a (- & +) on the 2nd Stage. On the left side. - is closed and + is open. I have a XTX 200 with a XTX 40 Octo.

Keep it on (-) when you enter water and then afterward put it on (+).

It's shown in the USER manual if you have if not download it on Apeks Marine Equipment Ltd



If not just a simple tune-up at your LDS will fix it.
But try the switch first.

It think the difference between the XTX-50 and XTX-40 is like 25$.
Dont know.
 
Thanks for all of your helpful responses.

You can just add the knob to the XTX 40... Accessories To isolate that second stage and prevent the continual loss of air.
The venturi control is what you would use to adjust the breathing resistance not the free flow control knob. The free flow knob stops the flow of air completely! It doesn't seem to me that this is what you want.

Wys.

Stopping the air completely if necessary is exactly the feature that I am looking for. It was the reg freeflowing before even getting into the water that was the problem in the first place.

Thanks for the info on the accessory. I will look into it and try to see if my shop offers it.

I
Or, you can do what I do with my Titan LX's and Apeks ATX 40: carry a small allen wrench which fits the allen screw in the side of the second stage. I believe Apeks is a 5mm. Turning this screw does exactly what the knob on the ATX/XTX 50 does, but not so conveniently. Usually, the only time this adjustment is truly necessary, is with a new reg, or one that has been newly serviced. This is because it usually takes a bit of time for the soft seat to be engraved by the hard seat. In "non-adjustable" seconds, most techs allow for this engraving, but some do not (or guess wrong), and a slight free flow develops.

I was told that this can be done in lieu of the cracking control knob. Unfortunately, I have the tendency to lose small tools, senility setting in, so am looking for a solution that is built in to the reg. Thanks for the sugestion, though.
 
Stopping the air completely if necessary is exactly the feature that I am looking for.

I really dont think it is. The part that the link goes to stops ALL AIR to the 2nd stage. It does not detune it.

Either
1. learn how to tune it yourself ( aparently with a allen/hex key).
2. Get the shop to tune it properly.
3. Get a XTX50 (AFAIK the XTX50,100 and 200 all have the same 2nd stage).
 
Hi Aoo,

Please take the comments above with a grain of salt - I do not believe that the information is correct. I had a problem with a newly serviced ATX40 occy free-flowing and turning the knob (where the cracking resistance knob on the ATX50 is) with a hex key did not fix the problem.

The correct way to fix the problem is to disconnect the second stage from the hose using two sets of pliers or wrenches and then adjusting the hex screw INSIDE the connection to the second stage's hose. Turning the screw 5 or 10 degrees (tiny tiny amount) will stop the free-flow.

Cracking resistance means the amount of pressure that is required to START the flow of air. A finely tuned reg should free-flow with the knob unscrewed all the way. When starting a dive the knob should be turned a half turn or more. Have you ever noticed how sometimes a reg will feel like air is "injected" into your mouth with very little effort? Or how the air seems to fill your cheeks when you put your face down in the water instead of looking straight ahead? The cracking resistance knob lets you adjust the extent of this effect - ie: when swimming in a current or doing a lot of face down diving. Some people like this - others put it in the middle and leave it. Up to you.

For what its worth the more pressure on the spring the faster it will wear out. Turn the screw all the way in when washing your gear and then store the regs with the knob turned all the way out (free flow)

The + and - adjustment is the venturi-assist thingy. Its a pre-dive/dive switch designed to prevent free-flow on the surface. Leave it on - on the surface and switch it to + when you put the reg in your mouth.

Hope this helps.

Regards,
David
 
https://www.shearwater.com/products/perdix-ai/

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