Scubapro Regulator Serial Numbers

[Bryan]

my Problem: I have 2 original MK 1 (1.gen) with following Serial numbers V-XXXX. They were produced exactly one after the other, so there was no mix....

You're talking about the 1st gen. MK I, then yes that would be odd to have the V-XXXX.
I have 2 or 3 of those regulators, let me dig them up and see what number is on them.

Didn't you get that MKI (1st gen) still in the box a little while back? That one has the V-XXXX on it?

Are you all referring to the original Mk-1 with the flow by balanced piston that had the (supposedly 100%) recall?

I have one of those.

Anyone knows the reason it was recalled? I have a theory based on the potential failure modes I have analyzed, but would like to know if there is some actual information.

I don’t mean to highjack the thread, so I will split the subject if needed.

Thanks

You mean one like this?

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[luis]

That is the flow through piston Mk-I. The internals are the same as the MK-V.

This is from another thread I posted this morning:
That Mk-I first showed up in the 1967 catalog, but basically the same regulator showed up in the 1965 catalog with the Mk-V name. The difference was actually that the second stage was the 108, not the 109. The 109 was introduced in 1967.
In the 1965 catalog the Mk-I was a flow by piston balanced regulator that ended up being recalled.

The last catalog were the Mk-I shows up is 1977.


The original MK-I is the one on the pictures below. Those pictures are not mine, but I do own one of those regulators.
I can't remember where the pictures came from, some might have been eBay, some from Karl... Sorry I can't give proper credit.





Notice the opening at this end. The piston end is exposed here as part of the force/ pressure balancing design.








The regulator came with the original 108.




Here is the Scubapro catalog page:





This is a Healthways drawing of the same regulator. Scubapro, Healthways, And White Stag all three offered the same regulator design. I believe the design was came from Sherwood Selpac. Maybe I read that earlier in this thread.




I am trying to post pictures of the guts, but I am having trouble up-loading pictures.

[luis]

Here are pictures of the piston in the original Mk-I.
This is a flow-by balanced piston with three O-rings and a seat that can be seen in that step. The seat sealed against a volcano orifice.

It was an interesting idea that works in theory, but my guess is that it could easily bind since the piston was riding on three sealing surfaces.

[Bryan]

Luis, can you send me the scans of the drawings you have for it so I can archive them please. I'd like to study more on it cause I'm not sure if I get it 100% or not.

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