Conshelf XIV exhaust valve?

[reefrat]

I have had an immaculate Conshelf XIV for a while that I got serviced recently and took for a dive last week. I do not believe the shop replaced the exhaust mushroom valve, it is a yellow one and apparently if it looks OK then usually there is no need to replace it. The reg breathes well enough but there is noticeably more resistance to exhalation than I would expect and I am wondering if maybe the old silicone valves do eventually get stiffer than they should be.
Does anyone know if I would get lower exhalation resistance if I bought a new replacement valve like the ones on sale at VDH?

 

[redacted]

I have had an immaculate Conshelf XIV for a while that I got serviced recently and took for a dive last week. I do not believe the shop replaced the exhaust mushroom valve, it is a yellow one and apparently if it looks OK then usually there is no need to replace it. The reg breathes well enough but there is noticeably more resistance to exhalation than I would expect and I am wondering if maybe the old silicone valves do eventually get stiffer than they should be.
Does anyone know if I would get lower exhalation resistance if I bought a new replacement valve like the ones on sale at VDH?

My Conshelf XIV exhale has not more resistance than any of my 2nds - at least nothing I can notice. I don't replace exhaust valves until I find a problem. You might want to open it up and make sure they didn't do anything stupid like lube it or leave something that is fouling it.

I don't carry exhaust valves in my travel save-a-dive kit any more (I do carry a complete regulator rig ready to go) but I do keep a few of each of the more common sizes at home in my parts stash. A new spare will let you know for sure if there is a problem with the old one.

 

[reefrat]

My Conshelf XIV exhale has not more resistance than any of my 2nds - at least nothing I can notice. I don't replace exhaust valves until I find a problem. You might want to open it up and make sure they didn't do anything stupid like lube it or leave something that is fouling it.

I don't carry exhaust valves in my travel save-a-dive kit any more (I do carry a complete regulator rig ready to go) but I do keep a few of each of the more common sizes at home in my parts stash. A new spare will let you know for sure if there is a problem with the old one.

I will open it up and check the valve seat for any stickiness or residue, is it possible to buy a new exhaust valve replacement without buying the whole service kit? In any case the kit is only $12 and will get used eventually so I might buy it and replace the valve to see if it makes a difference?

 

[james croft]

AWAP suggestion sounds like a good one. A sticky mushroom valve might cause a problem if it doesn't open all the way when exhaling. I took a Conshelf in for an overhaul about 15 years ago. After I got it back I did not do a suck test before diving it or I would have found the problem. I drew in a breath with the air on and it was the smoothest breath with no resistance. I was in a noisy environment and did not notice the usual whoosing noise that you get when you inhale. I jumped off the rock I was on into the rapids of a river I was diving and took a big breath of water. There was no exhaust valve installed.
Normally most problems occur after an overhaul. It sounds like a stick exhaust valve to me.

 

[redacted]

I don't use my Conshelf but I took the cover off just so I could see what we are talking about. Mine is also a yellow valve. You might try getting someone else to breath yours so you can watch the valve work. It is pretty easy to see it using a flashlight and looking through the end of the exhaust tee. Modern exhaust valves seem to be pretty reliable devices. (I understand they were not always that way.) They sure don't get stiff over night. The valve is not usually included in a service kit but, if all else fails, stick a new one in and see what happens. Worst that can happen is you will have a spare on hand.

They really are a well built regulator.

 

[reefrat]

I don't use my Conshelf but I took the cover off just so I could see what we are talking about. Mine is also a yellow valve. You might try getting someone else to breath yours so you can watch the valve work. It is pretty easy to see it using a flashlight and looking through the end of the exhaust tee. Modern exhaust valves seem to be pretty reliable devices. (I understand they were not always that way.) They sure don't get stiff over night. The valve is not usually included in a service kit but, if all else fails, stick a new one in and see what happens. Worst that can happen is you will have a spare on hand.

They really are a well built regulator.

Yes they are very nicely made and quite pretty (IMO) if you get a clean one!
Overall I would say that their breathing performance is plenty good enough for any recreational diving and I have never noticed any shortcomings in that regard (my main reg is an Atomic T2x).
I do like the IP set a little higher than usual for the Conshelf- about 145 lbs, and I do not do any cold water diving so that is not an issue.
I only wish that the comfobite mouthpiece would fit them, but it is a larger size.
Any way, I will do as AWAP says in the next few days and watch the valve, in fact I will probably wipe the valve flange and seat anyway to ensure it's clean.
Cheers

 

[Nemrod]

If they are the yellow valve with the ribs on the underside, I have never enjoyed those. The clear silicone or blue silicone valves seem much softer as easier exhaling and at least as dry.

N

 

[reefrat]

If they are the yellow valve with the ribs on the underside, I have never enjoyed those. The clear silicone or blue silicone valves seem much softer as easier exhaling and at least as dry.

N

Very interesting!! I haven't seen these, are they factory parts and what about availability?

 

[KVDIVR]

If the shop used the USD overhaul kit it comes with a new yellow exhaust valve but as someone else mentioned unless some thing happened/damaged the original yellow valve it is not really necessary to change it out. The original exhaust valves were made of rubber (like the old masks) and they dried out cracked, warped and then leaked. Aqua Lung changed to the yellow silicon valves. I have never had to change mine since they made that change, and have had them since they were new. Another thing that affects both inhalation and exhalation effort is using the wrong mouthpiece I.E. to small of an opening.
Hope this helps
Also a Reg Tech 29years

 

[John C. Ratliff]

Reefrat, a lot of people don't realize that the Conshelf and Calypso regulators of that time have a metal cup at the bottom, which retains an air bubble in the regulator immediately under the exhaust valve (in most diving positions). This air bubble allows the mushroom exhaust valve to open in air, rather than water. Because of this, it opens fully, all the way around; mushroom valves with water around them only open partially, according to the U.S. Navy's Experimental Diving Unit. What this means is that underwater, this regulator's exhaust performs better than those with water contact on the exhaust valve.

SeaRat