MK5 Springs + 300 bar fitting

[Joris Vd]

Hello Dear Scubaboarders,

As some of you may or may not know i'm a bit of a scubapro mk5/109 fanatic. Now a while ago I finally managed to get a set op 5th port + din turret Mk5's from German second hand sites and combine it with my 109s I already had lying around.

I have the small problem with one of the mk5's that although it does not creep a single psi which is great, the IP is stable at 118 psi, which seems a tad low compared to what Scubapro recommended in the old manuals.

I talked to a scubapro rep at an event a while ago and he was talking about my kit , and I told him I don't take the mk5's out alot because I have 300 bar valves and I dont want an extra huge chrome adapter piece on an already big regulator. Now the rep claimed 300 BAR fittings were once available for the mk5 . . . Is this correct? Or was the rep mistaken?

Long story short:

Is there a 300 bar DIN adapter for the mk5 I'm just missing in all the catalogs?

and

The 118 IP is with the highest Seat available, so should I just source a new spring or shim extra?

Or could I just tune my second stage with that low Ip and be fine ?

 

[rhwestfall]

I don't know about any currently available DIN for the mk-5, or if one was ever available in 300 BAR.

as to IP - add shims (ideally, a new spring seems appropriate, but finding one is the issue).

That IP is rather low....

YMMV

 

[ams511]

Regarding the IP, remember the official Scubapro rebuild kit contains 3 seats for the MK-5 so you may want to use a different seat. There is a thread on Scubaboard discussing it. Maybe @couv , @herman, or @halocline will chime in, they are the resident experts on this.

 

[NotSure]

I believe there were a few different versions of the MK5 DIN adapter.

 

[NotSure]

 

[Joris Vd]

View attachment 512374 View attachment 512375

Oh lord, almighty. The holy grail of din fittings.

Does anyone have a source to get some?

 

[swimlikethefish]

If you had thread pitch you could have a local machine shop duplicate them.

 

[halocline]

Is there a 300 bar DIN adapter for the mk5 I'm just missing in all the catalogs?

and

The 118 IP is with the highest Seat available, so should I just source a new spring or shim extra?

Or could I just tune my second stage with that low Ip and be fine ?

To raise the IP, you want to use the lowest (shortest) seat, not the highest (tallest). I'm not sure if that's what you are referring to. The short seats have a "+" on the back. The tallest seats have a "=" on the back. I always use the short "+" seats in my MK5s, and I still have IP around 125-130 on them, sometimes with a shim or two. I think SP says you can use up to 3 shims. Those shims not super accurate IME; I think a good project might be to source hard plastic, maybe teflon, shims of varying thickness to use as IP adjustment on the MK5.

You will notice a difference in performance if you get the IP up into the high 120s. Not much, and certainly they still breathe great with a balanced 2nd stage even if the IP is low.

There are DIN retainers for the MK5; they're a little hard to find. I eventually found two, and I suspect I'll end up using those MK5s for my cave regs at some point. (I just finished full cave!) There is a work-around; the very common universal SP DIN connector is about 2 mm shorter and Awap has had good results just using a 2mm thick brass washer that fits in the body of the reg and allows the shorter retainer to 'bottom out' and torque correctly. You still use the o-ring on the side of the retainer, not the end like the MK 10, 15, 20, 25.

 

[Rusty Shackleford]

I wish VDH would do a run of DIN adapters for the MK-5.

 

[rhwestfall]

I wish VDH would do a run of DIN adapters for the MK-5.

We can all wish, but the cost of tooling would likely lead to the need for a large purchase quantity or the per unit price would be insane. That being said, I doubt there is enough of a market demand to order a quantity sufficient to balance out the production cost...