Any advantage to converting SP MK10 to DIN?

[PeterSZA]

I have a scubapro MK10. It's rated at 3000 psi. I can't use it on HP tanks. Is there any advantage to converting it to DIN?

Thanks.

 

[Got2Go]

Advantage: It will be DIN.

Have a look here, if you haven't already.

Din adaper with sp mk10 question

 

[rhwestfall]

Please clarify what do you mean by "can't use it with HP tanks"? The 3K yoke is fine for 3442 (though those are not actually HP, but that is another whole topic)....

 

[PeterSZA]

Bob, I was going by the "3000 psi" stamped on the yoke screw (of the older MK10, the screw that looks like a metal banana). But the link Got2Go just posted addresses my concerns. Thanks all! I'm off to get the adapter!...

 

[rx7diver]

Bob, I was going by the "3000 psi" stamped on the yoke screw (of the older MK10, the screw that looks like a metal banana). But the link Got2Go just posted addresses my concerns. Thanks all! I'm off to get the adapter!...

PeterSZA,

I purchased my first Mk 10 in 1987 and my next two shortly thereafter. Purchased new. I converted them to DIN in 1989 or so, when I purchased my first tanks, Sherwood Genesis HP 80's (3,500 psig tanks made by PST). No problem whatsoever all this time.

Don't discard your yoke fitting, though. I switch back to yoke when I use my Y-valve. Also, when I travel, I make sure to take my yoke just in case: If I get a rental tank that doesn't have a convertible valve, I prefer to switch my reg back to yoke rather than use an adapter.

BTW, none of my DIN conversion kits came with a warning about maximum 3,300 psig tank pressure.

Safe Diving,

rx7diver

 

[DogDiver]

It's rated for 3000 because that's the rating on the yoke and only the yoke portion of the regulator.

 

[halocline]

If you're converting to DIN because you want DIN, fine. But there's no need to convert it in order to use 3442 PSI special permit tanks like the worthington HP100. The heavy SP yoke is fully capable of handling the additional pressure. I've used mine on my HP100 many times.

That old thread takes about the bushing system on the later MK15/20/25. The bushings tightened the clearance around the HP o-ring and supposedly reduce extrusion. It is true that my MK10s display a raised IP at higher tank pressures; I can't remember exactly how much rise there is between 3000 and 3500 PSI, but it's maybe about 5 PSI higher IP. This does not happen on MK15s or 20/25s that I've worked on. The only reasonable explanation is that the slightly larger gap around the HP o-ring in the MK10 allows a bit more extrusion, which adds some friction to the piston and raises IP.

In this sense, I don't think MK10s are ideal for HP tanks. They work fine, but given a choice, I'd use a MK15/20/25 when diving with HP tanks, especially if you use HP tanks frequently. This has nothing to do with DIN/yoke.

In fact, one day I'll get another MK15 or a pair of MK20s to use with HP doubles. My doubles use currently is limited to AL80s and it's likely to stay that way for a while.

 

[PeterSZA]

Thank you all for the replies so far.

rx7diver, I'm having it converted at my LDS. Didn't know it was as easy to do as you seem to be indicating. Is it just a matter of unscrewing that big nut in the yoke that sits around the air opening? How do you get a wrench to wrap around that?

btw, I also purchased mine in the late 80's!

 

[rx7diver]

Is it just a matter of unscrewing that big nut in the yoke that sits around the air opening? How do you get a wrench to wrap around that?

btw, I also purchased mine in the late 80's!

DISCLAIMER: I am NOT a "certified regulator repair tech"—by any stretch!

There is a special tool. It's flat and thin, with a rectangular hole cut in the center that slips over the yoke and "straddles" the yoke nut, and a handle for each hand on opposite sides.

However, I personally just use a BIG adjustable wrench. I think mine is a 12-in Sears Craftsman. Careful: Don't use one that's too small, or you'll mar the yoke nut (which, being chromed brass, is relatively soft). Ask me how I know about marring the nut! You want one that is big enough that the wrench jaws fit across the entire length of the flat sides of the nut. 12-in or, certainly, 14-in should work. Depending, I might choose to remove one or more hoses.

So, I find a vise and open it just enough so that my clean and dry 1st stage, padded with a soft towel, only just fits horizontally between the vise's jaws. (Don't clamp down!) I apply my BIG wrench to loosen. (Lefty loosey, righty tighty, correct!!??) Careful: This BIG wrench provides a LOT of leverage. I really don't have to apply much force at all. That's it!

Careful: Don't let anything fall through the now open high pressure hole into the inside of the 1st stage.

I make sure the threads and O-ring channel inside this hole are clean. I service the static O-ring that will sit between the male DIN part and the 1st stage. I screw the male DIN part finger tight into the 1st stage and then tighten with an Allen wrench (Allen key). I suppose I should use a torque wrench, but I don't. Don't forget the sintered filter!

Easy peasy. Should take your Scubapro dealer only a couple of minutes—more or less, depending on whether he/she needs to remove/reinstall hoses.

Safe Diving,

rx7diver