7' Hose harder to breathe from?

[DustyC]

Is it possible that an undesired adjustment was made to the second stage when it was attached to the new hose?

I did it with an SP technician/dealer watching. So I hope not. But I'll head back up there and check when I switch.

 

[redacted]

I did it with an SP technician/dealer watching. So I hope not. But I'll head back up there and check when I switch.

The problem is not normal. So now it is a matter of troubleshooting to isolate the culprit. The hose and 2nd stage are prime candidates. You also need to verify that your perception is correct.

 

[dumpsterDiver]

I once made a regulator hose spliced to a pneumatic tool hose for use underwater on a pneumatic chisel. the chisel was operated in short bursts and required good pressure and I assume decent air flow. I had performance problems with a short hose. However, when I added a longer pneumatic hose of 6-8 feet, it solved the problem and the device worked in bursts with no loss in performance. It was my impression that the longer hose acted like a an intermediate pressure reservoir and was the source of the improved performance.

I would think (admittedly from just this one example) that the longer hose would not degrade performance?

 

[Akimbo]

Yeah, weird stuff can happen. In some cases the longer hose serves as a reservoir or volume tank... until the hose loss and turbulent flow cancels everything out.

 

[DustyC]

The problem is not normal. So now it is a matter of troubleshooting to isolate the culprit. The hose and 2nd stage are prime candidates. You also need to verify that your perception is correct.

A friend checked and agreed. I'll check both, but the issue came with the hose.

 

[Nemrod]

I too would check the first stage IP adjustment. Yes, a longer hose would (eventually at some length) cause a greater dynamic pressure drop which would definitely effect the performance of a highly tuned second stage. However, I suspect a damaged hose or a low/marginal IP.

If the IP is good and the hose is good then check that the second stage is really tuned correctly. For which you either need a repairman with a Magnehelic or you need a Magnehelic. However, it is possible to have a decent minimum cracking effort adjustment but the lever not offset the seat sufficient to allow the expected flow (usually due to low lever height adjustment or damaged or incorrect lever). This is one of the issues that many repairmen run into when they "tune" regs with a pair of pliers and a screwdriver and yet have no instruments to check cracking effort or to measure flow (which a Magnehelic does not). Or if I might say do not know what the Hell they are doing.

N

 

[Akimbo]

As long as the problem remains so noticeable that you don't need instruments to detect the resistance, you should be able to isolate it by swapping hoses, first, and second stages.

 

[Nemrod]

If you put a gauge at the second stage and another gauge at the first stage and then vary the length of the hose you can indeed see a dynamic pressure drop, which is related to the length of the hose. I have found it not to be significant, but, by the way, greater than inserting a 90 degree fitting, also insignificant.

If the resistance is felt immediately upon inhaling or does the resistance increase as you continue to inhale?

And I will disagree about not needing instruments, subtle adjustments can and do effect regulator performance, often in a big way, the variable in this case may be the hose, the cause is likely something else (unless the hose is indeed damaged/defective), the longer hose is exaggerating the already existing fault.

N

 

[Akimbo]

I didn't mean to imply that instruments are not needed, only that the perceptible problem can be isolated if you don't have the instruments. If you can isolate it by swapping components then you will be reasonably certain that it is the hose or an adjustment problem on one of the two stages... which does require instruments to do properly.

 

[DustyC]

If you put a gauge at the second stage and another gauge at the first stage and then vary the length of the hose you can indeed see a dynamic pressure drop, which is related to the length of the hose. I have found it not to be significant, but, by the way, greater than inserting a 90 degree fitting, also insignificant.If the resistance is felt immediately upon inhaling or does the resistance increase as you continue to inhale?And I will disagree about not needing instruments, subtle adjustments can and do effect regulator performance, often in a big way, the variable in this case may be the hose, the cause is likely something else (unless the hose is indeed damaged/defective), the longer hose is exaggerating the already existing fault.N

From cracking on through the inhalation.