Apeks DST 5th port - freeflow issue

[scuba_mc]

Hi

Had my local LDS order and install the Apek 5th port kit on my DST 1st stage.

Problem is that ever since this mod. my XTX50 2nd stage plugged into this port now freeflows ever so slightly even with the cracking knob completely closed.

LDS is now recommending the 1st and 2nd stage go to Apeks for a service to get tuned/balanced properly.

Anyone know what the problem could be and how I could troubleshoot and resolve myself, obviously without any specialist tools.

 

[Hickdive]

When they installed the 5th port they probably haven't checked and adjusted the interstage pressure as they are supposed to. It is now probably too high, causing the problem you describe.

This is a very simple fix but you need a hook spanner, a 6mm hex key and an interstage pressure gauge. If you have these then all you need to do is connect the regulator to a full cylinder, plug the IP gauge into a BCD hose and open the cylinder to pressurise the reg. The IP should lock-up (settle) at 9-10 bar. If it doesn't then use the hook spanner to remove the environmental seal clamp (that's the outermost of the two clamps), lift out the pressure transmitter button, slot the hex key into the hex fitting exposed then turn clockwise to raise the IP or anti-clockwise to lower it. Purge the second stage between adjustments to get the true reading and don't let the hex key touch the diaphragm under the adjuster as that will throw your reading off.

Once adjusted, leave the reg pressurised, pop the pressure transmitter button back in, screw the environmental seal clamp back on and tighten with the hook spanner. Turn off the air, purge the regulator, remove it from the cylinder and the job is done.

There are alternative causes (damage to the HP seat or HP orifice during installation of the 5th port or damage/omission/non-lubrication of the balancing chamber o-ring for example) but they're probably beyond the scope of what you want to be messing about with. However, if you have an IP gauge you can work out if it is more likely that one of these other issues has arisen by watching the IP after lock-up. If it creeps gradually upwards until the second stage trickles then it is one of these latter problems.

If your LDS considers itself competent to supply and fit a 5th port kit then it seems a little strange that they don't have the capability to either diagnose the problem or conduct a service in-house.

 

[scuba_mc]

Thanks Hickdive

Unfortunately beyond my tools/skill level.

Yes I was surprised myself that LDS offered to install but did not want to attempt to correct the IP.

Guess it will have to go to Apeks... sigh

 

[ams511]

What Hickdive suggests sounds more difficult that it is. An IP gauge is between $10 and $20 depending where you purchase it from. It attaches to your BC hose, every diver should have one to check their regulator before diving. The reading on the gauge should be between 125 and 145 with 135 PSI being the best.

What could have happened is this. When the 5th port was installed the IP could have increased over what it was in the past which is causing the freeflow. The can be corrected in one of two ways 1) As hickdive mentioned 2) remove the hose from the second stage and while depressing the purge turn the orifice clockwise ever so slightly and reattach the hose and recheck. I would strongly suggest testing the IP first because if it on the high side it should be lowered. You do not need to send the regs to Apeks, just take them to an Apeks dealer that does their own service.

The dive shop should have an IP gauge (and a tank) so it should be able to be checked there.