1st Stage Hiss...

[Reef]

Everytime I connect my first stage to the yoke on my tank I hear a slight hiss.

The hiss goes away after a few seconds. I've soaked the area to look for bubbles without any luck.

I'm using HP steel 100's with a Delta 4 Regulator. Would you be concerned, or would you just leave well enough alone?

Thanks...

 

[Couv]

Everytime I connect my first stage to the yoke on my tank I hear a slight hiss.

The hiss goes away after a few seconds. I've soaked the area to look for bubbles without any luck.

I'm using HP steel 100's with a Delta 4 Regulator. Would you be concerned, or would you just leave well enough alone?

Thanks...

Hello Reefwatcher,

Because you have not been able to find a leak, right off the top of my head I would say that the hiss you hear is just the air going into the high pressure hose/gauge. The high pressure port on most regulators has a small orifice so that: 1) in case of a leak in the hp hose or gauge the loss will be minimized 2)prevents shock to the gauge. You can test this theory by removing the hose (air off and system bleed down of course) and put a plug in it's place.



couv

 

[herman]

Hello Reefwatcher,

Because you have not been able to find a leak, right off the top of my head I would say that the hiss you hear is just the air going into the high pressure hose/gauge. The high pressure port on most regulators has a small orifice so that: 1) in case of a leak in the hp hose or gauge the loss will be minimized 2)prevents shock to the gauge. You can test this theory by removing the hose (air off and system bleed down of course) and put a plug in it's place.


couv

I was thinking the same time. A different test, watch the gauge as you pressurize the reg, if the hiss goes away a little before the gauge stops moving, there is your hiss...and nothing to worry about UNLESS this has just started happening. I recently fixed a "broke" HP gauge...the tiny hole in the 1st stage end of the hose was stopped up...may be worth taking it apart and cleaning it.

 

[Couv]

I was thinking the same time. A different test, watch the gauge as you pressurize the reg, if the hiss goes away a little before the gauge stops moving, there is your hiss...and nothing to worry about UNLESS this has just started happening. I recently fixed a "broke" HP gauge...the tiny hole in the 1st stage end of the hose was stopped up...may be worth taking it apart and cleaning it.

That sounds like a much easier way to check it.

Herman, what was the material blocking the hole? Was it on the plug/hose side or the regulator side?

c

 

[Reef]

Thanks for the advice.

Tonight I tried 2 tanks on the 1st stage, and of course it would not do it.

One tank was at 1500psi and the other at 2000psi.

I wonder if it's the dvt making the hiss when the tanks are at full pressure.

The O-Rings appear to be in good shape.

 

[redacted]

Such a hissing sound may also indicate an o-ring that is a bit slow taking a seat u nder pressure. I had that happen when I tried to use too thin of an o-ring in a scubapro superflow hose connection. You could also try removing hoses (one at a time) and instaling a port plug to isolate the problem. Just be careful not to remove all your overpressure protection. I'd be surprised if this were a problem with the DVT.

 

[realdiver7]

I've seen this happen on a couple of first stages when the yoke nut loosened up over time from attaching and removing the first stage, but the hiss didn't go away until I tightened the yoke nut. Check and make sure your yoke nut is snugged down tight by trying to turn it with your fingers. If it moves any, then it's not tight enough.

Since your hiss goes away on its own, it's probably not the yoke nut, but just one more thing you can easily eliminate.

 

[herman]

That sounds like a much easier way to check it.

Herman, what was the material blocking the hole? Was it on the plug/hose side or the regulator side?

c

Don't know what the junk was but it completely blocked to tiny hole in the hose. Cleaned it out with a pin and everything started working again. Also carefully opened the tank valve with the HP hose removed to blow out anything in the hose socket.

 

[Regtekdiver]

Does the Delta 4 in question have a DVT installed inside of the yoke nut retainer? Sometimes these DVT's can make a noise when the first stage is pressurized and even while breathing as well. Apparently this is due to the turbulence created by high pressure air rushing over the plastic molded plunger and spring inside of the yoke nut. I suggest bringing this unit to your local "LDS" and ask the technician to turn the spring around and try it then.

 

[Reef]

I just looked at some pics taken over the weekend.

The leak is coming from the connection from reg to tank. I tested this later.

I can say it's a very, very tiny leak. My LDS looked at the regulator after I noticed a slight nik. He said it was barely noticeable, and not to worry about it.

I'm tempted to spend the cash, and order the part from the regulator. However I didn't notice where I really lost any air over the weekend. Also I'm diving Fabers which don't have the greatest valves in the world.