Should I Get My Regulator Checked Out?

[TheHuth]

As a reminder, I've only had 7 dives total, so I have a very limited frame of reference. I just had my regulator serviced at the beginning of February. Its only been out on one boat trip with me since for a total of 3 dives on it since being serviced. On the last dive, it almost seemed like the regulator was outputting too much gas. In other words, it seemed like there wasnt enough resistance when I went to inhale, as was getting a bit too much air. I didnt put much thought to this though, and chocked it up to my inexperience.

Just now I went out to my garage. I wanted to verify all of my tanks fullness. I popped my regulator on the first tank, and after turning on the gas, I went to inhale and there was actually a fair amount of resistance before it delivered any gas. After that though, it seemed to deliver air without any issue. It almost seemed like it was stuck at first (although very minimally).

Can anyone with a fair amount of experience chime in here? Would what I'm describing make you nervous, or is this fairly typical? I have an Aqualung legend, which is supposed to be a really good regulator from what I'm told. I'm going to be doing my AOW in a month, and dont want to have any issues on the dives. If I need to take it back to get it looked at, now is the time.

 

[2airishuman]

1) How does it compare to your secondary?

2) Did you try it in the sink? That is an easy, objective way to measure the amount of vacuum required to get it to open. If you point the mouthpiece up and start to submerge the reg, it should open when the diaphragm is under about an inch of water.

3) Do you have a dive/predive lever or a seat adjustment? Are they set correctly? In general both should be set all the way in the "minimum breathing effort" direction unless there is a problem with freeflow due to current (for the dive/predive lever) or regulator wear (for the seat adjustment).

 

[docmartin]

Would not make me nervous. Too easy to breathe? Unless it free flows when you put the pressurized second stage in the water there is no issue.
After sitting dry for a bit it is also quite normal that it sticks on the first breath when not submerged.

 

[redacted]

Most 2nd stage regulators take advantage of a venturi effect which reduces work of breathing once the gas starts flowing. It works like a siphon. It can produce positive pressure breathing where it feels like your regulator is trying to force gas into your lungs. With your legend, you have an adjustment knob where you can control this effect if it makes you uncomfortable.

I would not worry about your experience in the garage. There may have been a little dirt or deposits interfering with the first breathing cycle. You may want to reconsider your user cleaning procedures. I favor a long soak over a simple rinse.

 

[Crowley]

The Aqualung Legend is awesome - I have an older model which I've used as a dive professional for 5 years and it's been fantastic; never let me down.

It's important to remember that there should be very little effort involved in breathing from a regulator; breathing resistance should be minimal, although that will always depend on the design of the regulator but it's what manufacturers are trying to achieve. Some are better than others, and naturally that tends to vary between the low and high ends of the market.The aim is to make breathing underwater as easy as it is at the surface. A correctly balanced Legend - which is towards the higher end of the market - will be pretty close.

Regarding the initial resistance when you took your first breath in the garage, I wouldn't worry too much. As per awap's post, it may well be that the mechanism has seized slightly - perhaps because of residue from imperfect cleaning, or the natural tendency of mechanical devices to get a bit stuck without use. Based on experience, I don't think it's anything you need to be worried about. Perhaps have your instructor check it beforehand, or take it back to the shop and have the service people check it quickly - for which I hope there won't be a charge. Most dive pros would happily do that for a concerned diver.

Hope that helps,

C.

 

[Belzelbub]

I think it sounds fine. If it's the standard Legend, it doesn't have a breathing adjustment, but does have a venturi switch. By design, the venturi assist is supposed to help the valve stay open during the inhale cycle without requiring the diver to exert much effort to inhale.

Also, as I recall, the Legend is an overbalanced diaphragm. Depending on who you ask, the overbalanced diaphragm is either intentional, or a design flaw that became a feature. By nature, the overbalanced first stage will have a higher IP at depth than a comparable balanced reg. This can result in the feeling you described initially. It could also lead to freeflowing, but that's unlikely if the reg is tuned properly. So, as long as it's not freeflowing it sounds fine on the too easy breathing front.

You'll more than likely get used to it, but if you find it to be uncomfortable, you could ask your dive shop to tune it to the lower side of the IP spec on the next service.

Regarding the other issue, sounds normal as well.

 

[Oldbear]

The initial sticking could also be a result of the 2nd stage just being dry...the regs work better when wet.

If the Work of Breath is to soft for your liking you can ask your technician to adjust the "Cracking" pressure on the second stage. The cracking pressure is the amount of force it take to inhale which opens the flow of gas into the regulator. My GF has a super soft one where I like mine a little tighter. If mine is too low I too feel like I am getting to much air flow per breath.

 

[TheHuth]

Thanks for all the feedback everyone

 

[mmerriman]

in general if you think your life support equipment isn't operating as expected and you start to think "should I.." the answer should be yes.

 

[redacted]

in general if you think your life support equipment isn't operating as expected and you start to think "should I.." the answer should be yes.

You have a choice. Pay the man or learn about how your regulator works.