DST & TX50's Performance On Long Hose

[ColdFusion_GT]

Can someone help me with these questions?
1)Can the DST medium pressure be adjusted?

2)Does the 7 feet hose decreases the performance of the TX50? Its because when i was on the 5 feet hose, when i twist the knob halfway out the TX50 can give a steady freeflow but after switching to the 7 feet hose 2 days ago, when i rigged the system, i realised that the knob has to be turned 3/4 out b4 it can give a free flow. Must I adjust the DST to give it more power?

3)If the DST medium pressure can be adjusted, will it affect the other LP eg. inflator hose,back up reg tendancy to free flow?

Please help out, newbie here, sorry and thanks!

 

[steve2281]

I'll give it a try; someone else can follow up later:

DST means "Dry Sealed Turret". It is the type of first stage you have. There is a bit of confusion concerning how Apeks names their first stages. ex. UST= unsealed turret, DS4= dry sealed & no turret. Many 2 stage sets are sold as ATX50 but they are actually the dst first stage and the atx50 second stage. Same thing for TX50, TX40, ATX40.

The adjustment knob on your second stage is used to fine tune the "cracking" pressure as conditions change during the dive. It will not give you more air, just change the resistance needed to crack the reg open.

You can adjust the intermediate pressure on any Apeks reg. Many people keep it about 120-125 (lower than many brand/models). Let a tech check yours out.

Long hose does not effect performance.

 

[rescuediver009]

Can someone help me with these questions?
1)Can the DST medium pressure be adjusted?

Yes

2)Does the 7 feet hose decreases the performance of the TX50? Its because when i was on the 5 feet hose, when i twist the knob halfway out the TX50 can give a steady freeflow but after switching to the 7 feet hose 2 days ago, when i rigged the system, i realised that the knob has to be turned 3/4 out b4 it can give a free flow. Must I adjust the DST to give it more power?

NO

3)If the DST medium pressure can be adjusted, will it affect the other LP eg. inflator hose,back up reg tendancy to free flow?

Yes

 

[JS1scuba]

Can someone help me with these questions?
1)Can the DST medium pressure be adjusted?

2)Does the 7 feet hose decreases the performance of the TX50? Its because when i was on the 5 feet hose, when i twist the knob halfway out the TX50 can give a steady freeflow but after switching to the 7 feet hose 2 days ago, when i rigged the system, i realised that the knob has to be turned 3/4 out b4 it can give a free flow. Must I adjust the DST to give it more power?

3)If the DST medium pressure can be adjusted, will it affect the other LP eg. inflator hose,back up reg tendancy to free flow?

Please help out, newbie here, sorry and thanks!

Bring your APEKs regulator to an authorized APEKs dealer. They can adjust it to perform properly with your 7 foot hose. We have found that ALL regulators need a minor adjustment when adding a 7 foot hose. It's just a tweak and easy for a good reg tech to do.

Regards,

 

[jagfish]

Bring your APEKs regulator to an authorized APEKs dealer. They can adjust it to perform properly with your 7 foot hose. We have found that ALL regulators need a minor adjustment when adding a 7 foot hose. It's just a tweak and easy for a good reg tech to do.

Regards,

What adjustment needs to be made?

 

[ColdFusion_GT]

Thanks guys for all the info you gave! Yup, alright i would bring the system to tune it, so the normal Medium Pressure is still 120 -125 psi? why do people want to keep it low? prevent unnecessary free flow of the TX50?

 

[steve2281]

why do people want to keep it low? prevent unnecessary free flow of the TX50?

Yes.

 

[JS1scuba]

Thanks guys for all the info you gave! Yup, alright i would bring the system to tune it, so the normal Medium Pressure is still 120 -125 psi? why do people want to keep it low? prevent unnecessary free flow of the TX50?

The factory setting is 135 psi as is specified in the technicans manual. However it's not as simple as that. Because the 1st stages are balance 1st stages they need to be "spanned" at two different supply pressures before the final IP is set. This requires that they be set up on a test bench that can supply a steady 500 psi inlet pressure and a steady inlet pressure of 2500-3000 psi. After spanning to 120 psi the final ip is to be adjusted to 135 psi. This is a common procedure for many high performance balanced 1st stages.

If you received a new one with an IP set lower than 135 psi then someone messed with it before you bought it.

The reason some people have thier regulators reset to 125 psi is when they are using helium in the gas mixture. The small atomic weight of helium does not require as high an intermedate pressure to have it flow and still give excellent performance.

While the 1st stage adjustment is static before the hose. The 2nd stage needs to be adjusted if you put a hose on that is longer than the factory length (approx 28 inches).

Quality regulators will not go into "free-flow" unless the user puts it there. Meaning if you place the regulator in the water Face down instead of mouthpiece down. Or if you have gotten debris in the 2nd stage which interferes with the diaphragm. These 2nd stages have vents and a specifically designed diaphragm cover that is designed to minimize the possiblity of free flow under most conditions.

APEKS and thier big sister Aqualung regulators are outstanding permorers right out of the box. I use them both in some extreme conditions and without modification.

Regards,

 

[ColdFusion_GT]

Thanks JS1scuba, so do you think i should get the system tuned or just use it the way it is? I will be trying it at a pool tomorrow and tell you about how the brething is like?

 

[JS1scuba]

Thanks JS1scuba, so do you think i should get the system tuned or just use it the way it is? I will be trying it at a pool tomorrow and tell you about how the brething is like?

Sure give it a try -- doubtful you would find a difference in 10 feet of water. But give it a go.

let me know what you come up with

jds