Vintage Double Hose

The guy I got the twin 38s from threw in what appears to be an old piece of junk Scubapro MK2(?). Got it home and see there is no yoke screw hole - looks like a fill-whip end on the first stage but it screws on and does not slide back and forth like a fill yoke. Not sure how it would work. Ideas?

What you have is a MK-6. It is a MK5 with a special connection. It is spring loaded to initially close it but when you open the tank, it clamps tighter with the air pressure. To remove it, you close the valve, purge the reg then remove it against the spring pressure.

It might be bound up but you should be able to pull the yoke away from the main body (against spring pressure) enough to get it over a standard valve.

Herman wrote: ↑

Sat Sep 22, 2018 6:28 pm

What you have is a MK-6. It is a MK5 with a special connection. It is spring loaded to initially close it but when you open the tank, it clamps tighter with the air pressure. To remove it, you close the valve, purge the reg then remove it against the spring pressure.

It might be bound up but you should be able to pull the yoke away from the main body (against spring pressure) enough to get it over a standard valve.

Thanks Herman. I knew someone would know.

I tried to attach a couple of files, but could not due to invalid file extension. (pdf) I'll try to email them to you.

The MK6 is an interesting and unique first stage and a nice collectors item. But I would not do any serious diving with it. I used to have a one. Even after rebuilding it (including the pneumatic yoke) I found it disturbing that I could unseat it with a pull or bump when the tank pressure was below 1000 psi.

couv wrote: ↑

Sun Sep 23, 2018 3:59 pm

I found it disturbing that I could pull or bump the yoke when the tank pressure was below 1000 psi and unseat it.

Good to know! Thanks.

That might be the roughest looking regulator I have ever seen. I don't think you should put that into service with your cave diving kit.

BTW, the subject title made me think you had gotten bent.

I remember reading some posts on another forum about several fatalities with this first stage and being the reason they stopped production on it. Even at 3000psi it is easy to disrupt the connection. Cool collector piece. Looks good in my case.

could make for a handy "shop reg"...