'Pimp my dive !' Suggestions for modernizing my SP Mk 5 / 109 ?

[Zung]

My MK5 Din connector also has 7 threads. The one Thermo and two XS valves I have on my three steel tanks all state a max pressure of 3442, though the dive shop I use routinely fills them to 3600+.

When the MK5 DIN fittings are fully screwed into the XS valves there are two threads still visible. These tanks are in my basement. The Thermo valve is on a tank in my detached garage and it's snowing like crazy at the moment.

I must admit I know almost nothing about the different DIN configurations. If PADI does not offer a DIN certification I'll have to do some reading.

As per the DIN standard, 5 threads = 232 bar, 7 threads = 300 bar, 300 bar wheels work with 200 bar cylinders but not the other way around.

 

[ams511]

It appears VDH doesn't produce exhaust T's/purge covers, per other posters on this thread.

As Elan mentioned they had them in the store in the past. A few months back I received an email from VDH that they were reducing inventory, Bryan is a small businessman and slow-moving inventory is a drag on cash flow. I am sure that if there was enough committed interest (firm orders with deposits) he would do another run of parts.

---------- Post added January 24th, 2014 at 12:10 AM ----------

I'm fairly sure the MK10 diameter was a result of machining limitations, maybe financial, because SP wanted to bore the ambient chamber and HP piston journal out of one continuous billet in order to ensure accurate alignment. The others have threads connecting the two chambers, meaning that it's possible with thread tolerances to have a slight off-axis alignment between them. SP probably felt that they could lower the gap between the piston shaft and journal in this way, because the exact alignment ensured that the piston would not be pushed sideways by a less-than-perfectly-aligned ambient chamber. I'm not sure if that makes sense to you.

From what I remember DA Aquamaster had a post on this outlining the same reasons. By the time the MK-15 came out the milling machines were much better so the ease of machining a MK-10 was no longer significant. Also the MK-15/20/25 were designed for high pressure tanks.

---------- Post added January 24th, 2014 at 02:14 AM ----------

I've heard the MK 10 has an undersized piston, resulting in substantial IP variation as tank pressure changes.

The MK-10 also has better flow rates at low tank pressure so take your pick or use a latter MK-20/25 or MK-16/17.