SI Tech valves on Viking Pro

[Fritz01]

So I had a problem venting my suit last dive. It seems like the valve just isn't sensitive enough. I might have needed more weight but I was wearing 28lb + steel backplate with a ~200g undergarment.
Any thoughts? Anybody else have this problem with the valves? my suit is a little big, maybe that's the problem?

 

[Diver0001]

What do you mean when you say that it's not "sensitive enough"? Do you mean to say that you're having trouble venting the air in the suit?

R..

 

[Fritz01]

Yes with the valve fully "open" and air in the suit I have a hard time getting air out.

 

[buddhasummer]

I'm new to DS diving so take what I say with a pinch of salt.

First couple of drysuit dives I experienced a similar thing, in fact I initially thought the valve was jammed shut. Not saying this is the necessarily the issue you are having but it took me a few dives to understand how to move and manage the air in my suit. I now have no problem venting and actually turned in the valve to make it less sensitive. Unless your valve is faulty or contaminated if you move the air in your suit to the valve/highest point it will vent. The last dive, at safety stop, I did have to do a wee chicken type dance and flap my arm to vent the last bit of air but I'm pretty sure (using suit for total buoyancy) I was maybe a little light.

Hopefully some of the more experienced DS folks will chime in, I'm still a relative newbie in a DS so hopefully my post makes some sense. Good Luck.

(I can imagine if suit was too big managing/manipulating the air bubble would be more difficult)

 

[Fritz01]

Well maybe this will help clarify. I've dove a whites fusion tech with apeks valves and I the valve would dump air like crazy if open. Now when I walk in the water before the dive with the valve open on my viking (in order to remove air from the suit) I end up floating with a huge bubble in my suit for about a minute before the valve lets it all purge. I just feel like it purges far too slowly.
I'm sure you have more experience than me though. Thank you.

 

[Fritz01]

Also the valve is an Viking X2 I might just replace it. Thoughts?

 

[buddhasummer]

It might not solve your problem.

 

[claymore]

I can think of two possibilities. One if the suit is used the valve may be pluged with lint and or othere stuff. Two the undergarments are pluging the valve.

 

[Fritz01]

i took the valve apart, it's not a clog. I also wear hollis undergarments with vents cut in them.

 

[Diver0001]

Sorry for the delay, I forgot I was in this thread.

Ok. There are a couple of things that are relevant here.

1) the valve: Si-tech valves don't dump as easily as Apeks valves when they are fully open. That's just a fact. Si tech valves also don't leak when they're fully open which Apeks valves do on occasion. Whether you prefer one or the other is a matter of personal taste. I much prefer the si tech ones but I can imagine that not every one does. I'm not sure if you can replace them without getting the hole in the suit modified but if you can then there is no shame in doing so.

2) there could be a mechanical issue but it looks like someone suggested that already and checked it out without finding a problem. If you have the valve apart and there are any shims under the seating for the spring then you can remove them, which will reduce the spring tension a bit and make the valve more likely to dump when open. To be honest I'm not sure what you'll find when you open the valve. I haven't had one apart in many years but I don't remember shims as being a feature.... but you never know.

3) The position of the valve on the suit could be an issue. It's possible that it's not venting because you're not managing to get the valve to the highest point when you want to vent. Dropping your feet a bit (going a bit more vertical) and reaching across with your right hand to sort of guide the bubble to the valve might help in two ways; first, exaggerating it makes it easier to learn which body positions work better for dumping with the valve in that particular position and secondly, by using your hand as a guide you'll feel the valve venting. Sadly, some dry suit manufacturers put the valve in a sub-optimal position for venting out of a horizontal attitude so if that's your problem then you'll need to consciously work on exactly what position will do it for you.

hope that helps.

R..