DIN conversion MK20UL

[Packhorse]

Can I use a standard DIN aftermarket DIN conversion kit on a Scubapro MK20UL?
My main concern is galvanic corrosion between the 2 dissimilar metals.

If not can you get UL DIN kits? or does some one want to buy a MK20UL in good condition?

 

[Packhorse]

Bump.

 

[BlueWaterDiving]

I have 2 mk-20 ul and ScubaPro said to use the bass one and DO NOT nick it at all. I used a lot of christol lube. On the one I have and all is good.

 

[DA Aquamaster]

If you mean the Scubapro Universal DIN Conversion kit when you say "standard aftermarket" DIN conversion kit the answer is yes. If you mean another aftermarket conversion kit like the one sold by Trident, the answer is maybe not.

Stick with the SP kit and as indicated above keep the chrome intact, lubricate the threads with Christolube and most importantly use a torque wrench to ensure it is torqued properly to tje lower specs required on the MK 20UL.

 

[Packhorse]

Thanks. I have a feeling its a Trident but not sure. Its all metal unlike my MK25's that have a delrin hand wheel.

 

[DA Aquamaster]

I have had mixed success with the Trident DIN kits - some fit fine and others are a little rough in temrs of tolerances and the Mk 20 UL is one application where you want the DIN retainer threads to be a perfect match to the regulator body.

 

[Packhorse]

OK. What I will do is remove the 200 bar SP one off my MK20 and put it on my MK20UL and the trident one on my MK20.

 

[Luis H]

I am not familiar with the MK20UL, but it sounds like we have a dissimilar metal issue here, perhaps it is aluminum?

Well, I know a lot of people dislike this practice (now a days), but I have very successfully used Teflon tape to thread parts together that were made out of dissimilar metals. The Teflon tape isolate the dissimilar metals and seals any electrolyte (like salt water) out of the contact interface.

You want to be very careful that no Teflon material is beyond the threads because you don’t want shreds of Teflon breaking off and clogging something.

Again this is not the preferred practice, but it has been used very successfully (when done very carefully) in many applications. I totally avoid it with very delicate hydraulic controls, just because the tolerances are too tight, but in Scuba regulator that is not the case.

If the chrome is intact, you use an appropriate lubricating compound, and you take it apart to clean and inspect on a regular basis, it should be sufficient.

Some of the parts I have put together with Teflon were not going to be serviced for a long time and were going to be exposed to salt water.

 

[halocline]

I have a feelng that unless the torque spec for this is much lower than what I would imagine, teflon tape would be torn to shreds. Teflon tape is usually used as a sealant on tapered threads where the two parts are tightened to a light torque, often, with PVC parts, just to hand tight or a little more.

 

[Luis H]

I have a feelng that unless the torque spec for this is much lower than what I would imagine, teflon tape would be torn to shreds. Teflon tape is usually used as a sealant on tapered threads where the two parts are tightened to a light torque, often, with PVC parts, just to hand tight or a little more.

I can't agree with that. Tapered steel pipe has been put together for a long time with Teflon tape and often the standard practice is to "torque the heck out of it" and then a bit more.

Whether it is a tapered or straight pipe thread, the Teflon can get cut in some spots. But, for the most part it provides a bit of isolation and what is probably more important, it keeps the joint dry and avoids any the electrolyte in the interface.

It does work. I have seen very noble metals (like Stainless, Monel, etc.) screwed into aluminum (a less noble metal) and it does help substantially. For true Mil spec applications we always had to use an insert of compatible material, isolation washers (for the head of a screw), and even then we had some Mil spec lubricant for some of the threads.