High flow port and 1/2" hoses on Conshelf SE2

[Kupu]

I have recently become interested in buying a Conshelf reg. I didn't give them much thought until recently since they are mid range and lacked performance vs regs such as my SP mk16. But I have developed an interest in getting an additional reg which is simpler in design and easier to service, as long as the performance is acceptable. Specificlly, I need something that will breath OK in depths from 100' to 150'. This led me start digging thru the info available here and the Conshelfs are starting to look good.

After reading the posts here, I get the impression that a Conshelf XIV should be safe down to 150' or more. Then I noticed the SE2 having 4 LP ports, one of those being high flow. Also it looks like the SE2 has 1/2" ports vs the 3/8" ports on the XIV.

This leads me think I could expect a better breathing reg from the SE2 if I was to take it down to 150' along with the XIV and do a side by side breathing comparison?

So am I wrong to think the SE2 is my best choice? I know the XIV is well regarded and since I think Aqualung still sells these but not the SE2, I wonder if I'm reading too much into the advantages of larger hose diameter and a high flow port. I only need 3 LP ports so the additional one on the SE2 is not much of a factor.

I really like the brass case of the XIV second stages. If I was to get the SE2, I would probably replace the plastic cases with brass ones. So if there is no real performance difference related to the 1st stages, I would save my bucks and get the Conshelf XIV just to have the brass second stages.

I know there is already a lot of good info posted about these regs but could not find a solid answer to my question so any feedback is welcome.

 

[The Chairman]

It would seem to me that the ID of the hose is USUALLY the determining factor. Most of the LP hoses use the same ID hose which is similar to the 3/8" fitting ID. Now truthfully, I have never cut the hoses to measure them and the next time I have to replace them i will do just that.

To be sure, this is a SWAG on my part and I am more than willing to hear some real facts on what limits flow in these puppies.

 

[Kupu]

So it would come down to the difference between a high flow port and a regular LP port. I can't find the specs right now but I seem to remember an flow increase of about 10-15% with the HF port on my mk16. Of course that will vary from one design to another but I would guess 10% is a good average to work with for most regs using HF ports.

I would think that a 10% flow increase from the 1st stage could make a bit of a positive difference in ease of breathing, especially if I was getting deeper than 100'.

Regardless, I am starting to wonder if the real limiting factor here is going to be the unbalanced 2nd stage. Would the first problem to arise relate to not getting enough air from the 1st stage, or difficulty with 2nd stage performance?

Well, time to sleep on it. I believe I've read every post on Conshelfs at least twice today, my brain is getting full. But I'm having alot of fun learning about this. Thanks for the hose info NetDoc, I hadn't even considered that 1/2" and 3/8 hoses could have the same ID.

 

[DA Aquamaster]

You are giving the 1/2" port too much credit. It's a fad that passed. Most of the companies that used them have again went away from them. Other than the port size, the SE2 and Conshelf XIV first stages are idettical. In addition, I always felt the 1/2 port on the SE2 was in the wrong location to get clean hose routing. I prefer it be one hose farther around from the HP port. So given a choice, I'd take the Conshelf XIV.

The limiting factor in most regulator systems is normally the orifice in the second stage and it's a lot easier and more practical to put a larger orifice in a balanced second stage as the spring pressure does not need to get excessive to offset the downstream force of the air coming through the larger orifice.

As for ease of service, the Conshelf XIV and Mk 16 are virtually identical. Both follow the same basic design principles. In fact I'd say the MK 16 is a lot easier as you to not have to stack, align, compress and secure the whole spring, filter, backing ring and c -clip assembly in the HP end of the reg.

 

[Creed]

As for ease of service, the Conshelf XIV and Mk 16 are virtually identical. Both follow the same basic design principles. In fact I'd say the MK 16 is a lot easier as you to not have to stack, align, compress and secure the whole spring, filter, backing ring and c -clip assembly in the HP end of the reg.

Here's a tool that makes that job a heck of a lot easier:
http://www.vintagedoublehose.com/store/index.php?main_page=product_info&cPath=4&products_id=9

 

[Kupu]

Interesting to know that the mk16 and XIV are about equal with regards to ease of service. I had assumed the older design of the XIV would mean it would be less complicated to work on and adjust in between servicing. That along with the possibility of easier to find parts vs the SP regs was what led me to look closer at the Conshelf models. Also, I'm set on getting some brass 2nd stages.

So it looks like I'm back to my original plan to get the SP mk10 with balanced r109. I expect this setup would give me better performance than the Conshelfs anyway. The mk10 has about the same number of parts as the mk16 so I figure it will be a simple reg to work on also, maybe easier with the piston design.

I might pick up a XIV anyway just to play with since they can be so cheap to buy used. Oh man, where does it end...

 

[Bluey]

I picked up a real cheap SE3 and while I haven't tried it at those depths I am very happy with the way it breaths. It seems to breath dry in any position. Don't know how SE3 compares to SE2 but I have definitely become a Conshelf fan.

 

[DA Aquamaster]

The Mk 10 is dirt simple to work on and the parts count is low. The only mildly difficult part is replacing the HP o-ring. It's not hard, it just takes the right technique.

They make a specialty tool for it, but I find it's actually easier to use a couple of o-ring picks - one straight one inserted from the low pressure side to hold the edge of the o-ring in the groove and another pig tail shaped one inserted from the HP side to gently push the free end of the o-ring up so that it slides into the groove.

The R109 is an excellent second stage, especially if you upgrade it to R156 balanced adjustable status.

As for where it ends, that's a good question. Currently I have about 20 regs sittng around including several MK 10 and Mk 10 Plus Balanced Adjustables. PM me if you are interested in obtaining one freshly rebuilt.