LP seat came loose in my Argonaut Kraken

[kevjli]

On my 5th dive with my recently serviced Kraken, I started having a second stage leakage problem. I used the adjusting screw to tighten it down a little. It seemed fine when setting it up on the next tank. But once I dived, it was freeflowing a lot. When I took the second stage apart, I found that the LP seat had come loose (pic attached).

@rsingler …
Ideas on what I did wrong during service? How do I keep this from happening again?

Thanks,
Kevin

 

[happy-diver]

Tightening without looking is bad, had you unscrewed it reversed the seat, and screwed it back without
pressure on the seat all would have been good, what spring tension did you spin the seat on the orifice

I punch, those out by the dozens, out of used to be epdm but now standard buna, a bit of glue is good

Did they call it Spirotechnique because people used to have some

 

[kevjli]

When tightening or loosening the adjustment, I push on the diaphragm to pull the polymer away from the knife edge. I don’t think that my turning the adjustment caused the problem. The reg started out fine for a few dives and then slowly began leaking. I noted it getting worse before I tried the adjustment. I thought the seat had just worn in from service.

I like the glue idea.

 

[happy-diver]

It's unnecessary

What's with this "adjusting" and your seat is silicone you're doing something wrong you're there what is it

Mate with the combination of washers and spring and seat carrier and stuff something is getting hung up
Is there too much pressure getting to it to blow the thing open, and dislodge the seat, how would I know

 

[Scuba Lawyer]

Sometimes the simplest explanation and cure is the correct cause/solution. I have had a number of such seats become dislodged. Not on my Kraken but on other US Divers-based 2nd stages. The smallest drop of superglue prior to seat placement has always worked for me. Takes a bit more to clean when overhauled again but worth it. My 2psi. Good luck. M

 

[rsingler]

Looks to me like a tiny bit of a size mismatch. @happy-diver is right. That particular silicone compound is very "springy", and without a bit of glue may get sucked up out of the seat carrier by air flow. That seat looks a hair large for the carrier and wants to bulge at the edges.

A couple options...
1) Punch your own with a 9/32" punch and a sheet of FKM, EPDM or Nitrile. For that seat carrier, I'd use 1/16" instead of 2mm sheet. The advantage they have is slightly higher duro.
2) Add a tiny drop of waterproof cement. Superglue isn't my favorite because Cyanoacrylate gets pretty brittle. It sticks well to the carrier but comes off the seat. Silicone cement works well.

 

[rhwestfall]

Where did you source the seat from for the service?

 

[kevjli]

@rsingler Yes, the seat does seem slightly too big for the carrier, so it bulges a bit. I’ll try some cement for tomorrow’s dive, and get/make a new seat when I return.

@rhwestfall I’ll look at my records at home. The carrier is new because I dinged up the tiny screw slot on the end of my old carrier. I’m not sure if the new rubber seat came from the same source right now. Will check later.