D420! How about that?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

enjoy!!!
 
My MK 17evo has 142 ip at 3800, 3500, 900 and 500, it drops about 7psi while taking a breath never felt and change in use, I would expect the same with the mk19
 
My MK 17evo has 142 ip at 3800, 3500, 900 and 500, it drops about 7psi while taking a breath never felt and change in use, I would expect the same with the mk19

That's remarkable!!
I never ever had a 1st on my test benches that showed exact the same IP at 3000+psi and 500psi tank pressure, and I had quite a lot of them in my workshops over the last 30 years.
The best 1sts which repeatedly showed just 1 or 2 psi difference between 3000 and 500psi were some Legend 1sts.
All SP Diaphragm 1st with the latest valve configuration ( the old MK16 valve showed better IP stability, but was a Creeper), including one MK17 EVO I serviced, showed a minimum of 6psi ( up to 15psi) difference between full tank and almost empty.
Waiting for the results of Rob for the new MK19EVO.......:)
 
Do any of you guys have an idea as to why the concentric inhale and exhaust diaphragms was dropped?
 
Do any of you guys have an idea as to why the concentric inhale and exhaust diaphragms was dropped?
On the D 300,350 and 400? My guess is cost and or breathing machine WOB numbers.
 
Concentric diaphragms dropped on the D420 after being used on the previous D series regs. I had the impression that the D series’ reputation for easy breathing in a variety of positions was in part due to this feature.
 
Concentric diaphragms dropped on the D420 after being used on the previous D series regs. I had the impression that the D series’ reputation for easy breathing in a variety of positions was in part due to this feature.
Diaphragm mounted exhaust valve does allow for ridiculous low cracking pressures, but I imagine is much more expensive to produce. In the D420's case, I believe Mr. Singler alluded to evidence that they used case fault geometry to their advantage for the most likely use positions. Turned a limitation into an advantage as it were.
Respectfully,
James
 
Actually in one of threads years ago there was somebody, who claimed to work for SP.
If I remember right, he wrote that they had problems with exhaling value of the WOB numbers with the Ds, and that they would have to redesign the whole D400 exhaust valve to produce a good WOB number on the ANSTI Machines.
It was one of the reasons they stopped producing the old Ds.
So I expected them to go back to the classic design.......
 

Back
Top Bottom