Conshelf XIV overhaul question

[Ron]

Isolate it Jack. Swap the second stage, and see if it makes the same noise. If it does, swap the LP hose, and see if it still makes it. Then you know if it's first or second stage. Then we can go from there.

[Robohips77]

one thought also is ...does the ip return immediately to 140 or does it take a little for it to return to 140. (I know this sounds silly but ) is the tank turned on all the way or is there enough air in the supply source to let the ip rebound in a timely fashion. I have heard that "whooshing noise" on both occasions. Just some thoughts.Roger VF

[Herman]

I have heard of hoses that the internal construction has failed and collapsed causing strange second stage problems, I can see that also making strange noises as well.

[Greg Barlow]

At 140 IP inhalation effort was at or just over 1" on the Mag., even after messing with the lever height. I bumped up the IP to just shy of 150 and it is now just over 1/2" of effort. It is within the +- 5 psi of the 140 that the manual calls for so I think I will leave it at that

You will most likely experience a free flow with the regulator while in a normal swimming position. This is caused by an issue known as case-geometry-fault. There have been discussions in the past regarding this, and its impact upon tuning single hose regulators. Most of the older second stages cannot handle a cracking effort of less than 1.25" due to the distance from the center of the diaprhagm to the uppermost edge of the exhaust valve (while in various water positions). For example, while vertical, the reg would be stable. This is due to the top edge of the exhaust valve being in deeper water than the center point of the diaphragm. In a normal face angled down, swimming position, the uppermost edge of the exhaust valve is around 1.3" inches higher in the water column than the center of the diaprhagm. This depth difference causes a pressure differential that will typically cause the demand valve to slightly open due to the minor leak from the exhaust valve. This is the reason why manufacturers set a cracking effort range for their particular models.

Greg