Another little follow up on the D420/Mk19 pair.
Grumble, grumble.
Couldn't be happier with the Mk19's performance. As noted above, IP spread is only 5 psi from full to empty tank, which is a great improvement over my Mk17's.
But just out of obsessiveness, I pulled the plastic cap off the environmental seal end, and...
Under pressure, the environmental diaphragm was bulging, on BOTH my new 19's!
You can see how much ambient pressure would have to compress that bubble before the reg ever began to respond to depth.
Clearly, the reg's QC at the factory is not up to snuff, or (please tell me no) the building technician attached the seal with the reg unpressurized.
In any case, it was a very simple fix. I pulled the cap off with a large wrench (it was not overtorqued, which was a relief). I peeled off the seal and pressurized the reg. With the transmitter disc now flush with the case, I just smoothed the seal back in place, put a little Tribolube on the cap threads and replaced it, just slightly past hand tight.
On depressurization, the seal was now concave, like it should be.
A minor deal, but with two bulging seals and one freeflowing D420 in my new sets, I'm disappointed in Scubapro's quality control. If you buy a set from your LDS, make sure they do a function check before you walk out the door.
Still, two great new regulators, and I'm pleased.