Scubapro MK16 questions

[squizzthediver]

Hi everyone,

I just bought a brand new Scubapro MK16 / S550 reg set, and it's a massive improvement over the unbalanced piston heap of junk I was using previously. I do have a few issues with it though.

I want to start streamlining my gear, so I decided to go DIN with this new gear, and also to see if I could streamline the hoses so the whle package was neat and tidy. It doesn't seem to be working to plan however. I have the 1st stage mounted horizontally, and the HP and two LP ports are facing downwards. I thought that was great, until I figured out that I had to run the inflator hose from one LP port, and the secondary from the other. So that leaves my primary to come from the top of the 1st stage, thru an 'L' shaped junction, then onto my face.

The bend radii on some of the hoses aren't great either....hmmmm. So I'm kinda stuck. If anyone has struggled thru setting up a brand new 1st stage, and can help, I'd love to hear from you, or if you own an SP MK16, gimme a yell and advise on how yours is going.

Ps Is it OK to have those 'L' shaped adapters on the 1st stage?

 

[DA Aquamaster]

The Mk 16 incorporates High Flow Ports that should be used for the second stages which may further complicate your setup. And an L shaped junction on an LP hose to a second stage cannot be doing good things to the flow rate.

Hard to say without a picture or two of your setup, but you would probably get a more streamlined result mounting it vertcally and paying close attention to hose lenght. I'd just experiment and see what you can come up with.

A lot of "streamlined" configurations end up with very tight bends in the hose and I am not convinced that is an acceptable tradeoff. I have always preferred the MK 10/15/20/25 style reg and swivel cap design as it allows a lot of flexibility in hose routing on either singles or doubles. The MK 18 is a MK 16 with a swivel cap but it is unfortunatly not sold in the US for some unknown reason.

 

[SA-Diver]

I use a MK16 with a single steel tank.
With the standard hoses the MK16 (mounted vertically), is a collection
of hose loops just waiting to get entangled somewhere.
With a 7' hose on the primary second stage, a 22" hose on the backup second stage, mounted vertically with the backup bungied around my neck and the 7' hose routed correctly, it is much more streamlined and works quite well.

Kobus

 

[squizzthediver]

The Mk 16 incorporates High Flow Ports that should be used for the second stages which may further complicate your setup. And an L shaped junction on an LP hose to a second stage cannot be doing good things to the flow rate.

I agree. But I did think that HFP could be used with L adapters because of their 15% increase in flow - or so Scubapro say.

SA-Diver, you say the backup 2nd stage is mounted vertically? Is that a problem in overhead areas?

Thanks for your help thus far guys!

 

[SA-Diver]

My mistake.

The backup 2nd stage is bungied around my neck.
The 1st stage is mounted vertically.

I'll take some pic's tonight and post tomorrow.

Kobus

 

[DA Aquamaster]

I agree. But I did think that HFP could be used with L adapters because of their 15% increase in flow - or so Scubapro say.

The high flow ports get the increased flow due to a venturi effect caused by how the air is channelled out the port. Given the velocity of the air required to maintain the venturi effect, a 90 degree bend right outside the port will reduce the velocity and increase the relative pressure enough to eliminate the venturi effect. I think you are going to lose more than 15% of your potential flow rate with the elbow and the negative effects will most likely get worse with depth.

The Mk 16 has relatively little internal volume in the internal IP spaces and the high flow ports help to avoid any lag in breathing response under high demand situations. (the Mk 18 lacks the high flow ports but incorporates a hemispherical chamber to provide a resorvoir of intermediate presure air.) The Mk 16 has a flow rate of 87 scfm through the high flow ports which is adequate for nearly all situations but I am not sure what you would have through the other ports or through a 90 degree elbow attatched to the port.

It's largely a matter of priorities. There is nothing wrong with streamlining, but a little extra drag from a hose is not likely to kill you, overbreathing a regulator at depth certainly can.