MK20UL serviceability

[cb900c82]

New Reg Advice.

I was at my dive club the other day and I mentioned my MK20UL and S600 setup. A guy there said they were good regs, but not made for everyday diving. The aluminum, he said isn’t good for frequent diving in saltwater. He also said there’s a problem with the aluminum first stage and the hose connectors being different metals and I shouldn’t store it with the hoses connected. He made a point of saying I need to ensure the “collars” on the port plugs were used on the hoses. Now on the high-pressure port plugs there is a type of gray plastic washer, but I don’t see how it’d come off without destroying it and the o-ring. The low-pressure ports don’t have this (I got it used, previous guy took them?). I know enough about metal to know he’s right about certain metals not “playing” well together. But would Scubapro, or anyone make a reg you can’t keep together, or use often? Oh, the guy also mentioned if I sent it back to Scubapro, they’d send me a new brass one. He didn’t offer to turn it in for me, but I wonder is that would have been next if I didn’t have to run off. Any input on how correct his info was? Thanks.

 

[Dryglove]

My LDS owner had one of these regs and used it for a while. A few of the ports where the hoses screwed in became severely pitted. I know he sent it back in and am not sure if he got another UL or just a brass one. Ill have to ask him the next time i see him.

 

[Zaphod]

It seems the brass hose fittings and the Al first stage housing can be essentially permanently bonded together through galvanic action. The pile of grey and black washers found in a Mk20 service kit are there to minimize contact between the brass and Al, but they don't eliminate the contact made in the screw threads. It is best to either leave the hoses off or periodically just loosen and re-tighten the hoses. I'm sure I can scrounge up some of the washers if you need them - we throw most of them away since we don't see many ULs.

If the hoses are stuck, it can be sent back and replaced with a brass stage. So, everything bad you've heard about the UL bodies is true. It was a bad marketing-driven solution to essentially a non-existant problem.

 

[BILLB]

I own the brass and AL version for the MK20(UL). I have been using it for three years. It gets rinced after every dive session and has NEVER been a problem. It was once connected to a steel tank I rented in California and was found full of rust a couple of weeks later. It cleaned up (with a new piston) and is still going strong.