Conshelf SE3 service kit Question w/images

[SealFashion]

So recently I purchased a rebuild kit for my Us Divers SE3 Conshelf.

I received the parts quickly (yesterday afternoon) and as I had already cleaned and prepared for the build I was ready to install these immediately.

As I inspected the parts I focused on the HP seat and I was sort of thrown for a loop.

When comparing the "new" HP seat to the factory original coming out of the regulator I felt as if the 20+yr old original was pretty darn close to being better than the "new" one I just received.

It seems the stem on the "new" was an old stem that had seen much better days and this one had the sealing material replaced.

So....I am not against using "refurbished" parts...as long as the refurbishing brings the part into a like new condition.

Reason why I am concerned is that the HP seat is the only thing that comes into contact with the volcano orifice.

If the face of the HP seat is marred I worry it may damage the volcano orifice.....or am I just being paranoid.

Images attached...the original HP seat is the one with the blue seal material and also has part number on it.

....also the diaphragm retainer ring seems smaller than the factory original....is this normal?

Any and all opinions are welcome

 

[rsingler]

Your existing blue seat is a common aftermarket seat with a slightly softer seat material that shows the volcano indent more quickly but seals well. Your "new" seat looks to be an original, which means it's decades old. I don't think it's refurbished as much as the metal carrier is showing some corrosion.

The diaphragm also looks to be the old original. Make sure it's still flexible with no cracks in the rubber when you flex it. No problem with the thrust washer as long as the OD matches.

Frankly, most of us use all aftermarket parts for the Conshelfs these days. The diaphragms are more supple, and those blue HP seats are proven now. Most important, an "original" (i.e., really old) 2-006 HP oring for the balance chamber is likely to be very stiff, and much more likely to crack or leak after insertion. Better to use new nitrile.

 

[runsongas]

why nitrile over 90 duro viton for the 006?

 

[rsingler]

Unless you're running 100% O2, I'm becoming a slow convert back to nitrile over Viton these days.
A high quality nitrile oring has better 'anti-set' properties than Viton. It has better tensile strength. Under the microscope, I often see a smoother contour and less flash (though I'll concede that could be factory difference).

I used to be all in with Viton, and the indefinite storage lifetime was attractive. But since I'm servicing my own gear and there's no need (or advantage) to going a decade between services, it doesn't matter that my nitriles have only a 15 year lifetime.

I've had more late failures with my Viton o-rings than with nitrile. They feel subtly different when I fit them; especially the stiff ones.

I don't know.
I'm not a plastics engineer.
I know I'm just not afraid of nitrile anymore, except the cheap imports full of carbon black that fracture quickly.

Short answer?
Better anti-set. That's important in a hard o-ring under high pressure.

 

[tech3324]

Does the SE3 have a replaceable volcano orifice? I know my SE2's do not.

 

[rsingler]

The only difference between the SE2 and the SE3 was the SE3 going back to one HP port and adding a 4th LP port.
The bodies all the way back to the Conshelf VI just varied the port layout and added environmental sealing.
EDIT: You have to look at the Titans to find removable volcanoes. Wrong. See later posts...

I have always failed to see the endless fascination with the Conshelf. Indestructible, yes...until a tech scratches the volcano.
Titans, on the other hand?
The true workhorse. And maintainable forever.

 

[ND5342]

Does the SE3 have a replaceable volcano orifice? I know my SE2's do not.

According to the 2001 Aqualung Parts Catalog the SE3 and Conshelf 22 may have a removable crown. I have a 22 with one. The SEA / Cousteau had one as well.

 

[ND5342]

The only difference between the SE2 and the SE3 was the SE3 going back to one HP port and adding a 4th LP port.
The bodies all the way back to the Conshelf VI just varied the port layout and added environmental sealing.
You have to look at the Titans to find removable volcanoes.

I have always failed to see the endless fascination with the Conshelf. Indestructible, yes...until a tech scratches the volcano.
Titans, on the other hand?
The true workhorse. And maintainable forever.

I am surprised you said this as your knowledge is usually correct on these things, however the big difference between the SE3 and SE2 was a modified second stage case design with a change in diaphragm design as well. The SEA had two hp ports but the SE3 and SE2 only had one. Both also had four LP ports.

 

[happy-diver]

Never bothered with viton it seemed dusty and crusty when I pulled them from tank valves
all my stuff is compatible with 100% O2 swapped everything for epdm, compatible you say

Yeah right it's only designed as compatible as it gives off less toxic fumes when it's burning

And how does that apply to us

ASTUTE

 

[ND5342]

Never bothered with viton it seemed dusty and crusty when I pulled them from tank valves
all my stuff is compatible with 100% O2 swapped everything for epdm, compatible you say
yeah right it's only designed as compatible as it gives off less toxic fumes when it's burning

And how does that apply to us

ASTUTE

Yea probably not the best choice of word for the phrase.