DX overpressure question

[Robohips77]

Recently scored this DX and it is in remarkably good condition. I have a question. I found this valve in the exhaust side of the hose just upstream of the mouthpiece T. is this part of a hope page? So was the MP T valve for the venturri not working and this was their answer to it or was the duckbill leaking and this was their answer to a wet breather? Or both? The valve on the mouthpiece T is in fair condition and still in one piece. I have some thoughts on how to make a replacement but once i take this one out I am sure it is ruined. So I am going to rebuild the reg and leave that till last. I will attach pics tonight as I take them and download. Ideas welcomed.




These pics are pre cleaning. I have a few more to post after the cleaning process has been accomplished. I am still looking for a black period correct mouthpiece or even a gum rubber one may have been used. I have now sen pictures of both. I also noticed this one cam with two different sizes of tinnermans. 22's and 20's. I need to research which it might be.

[SeaHuntJerry]

NOs mouthpiece you have to contact me.
Jl

[swimjim]

I wish I could help you out Roger, but it's a really cool project! Thanks for posting the pictures. The DX was an unusual animal for sure.

Jim

[Phil]

THe yellow, in-hose exhaust valve is from a Divair reg.

[Robohips77]

Phil, thank you and more pieces of this puzzle still coming togther.

[gj1963]

Posting in this thread as it has a clear picture:



I need to fabricate this part - I think the original term is the check plate. I am hoping that someone that has one can measure the thickness. I saw in other threads the Bill made one himself. Should not be trouble for me to make, but need the dimensions if someone that has one can measure it for me please!

Thank You

[antique diver]

Geoff, I don't think that the exact thickness is critical, but mine was "about" 1/8" thick. The diameter was the same as the mouthpiece body. I made it a little differently than the original so that I could easily use a modified stock exhaust valve by just punching a hole in the center that snugly fit the little tube in the mouthpiece.. I don't remember if I posted a photo of the valve body made from brass, but if you need to see it let me know and I will be glad to provide it.

BT

[Bryan]

Geoff, I don't think that the exact thickness is critical, but mine was "about" 1/8" thick. The diameter was the same as the mouthpiece body. I made it a little differently than the original so that I could easily use a modified stock exhaust valve by just punching a hole in the center that snugly fit the little tube in the mouthpiece.. I don't remember if I posted a photo of the valve body made from brass, but if you need to see it let me know and I will be glad to provide it.

BT

Bill is right on the $$. I've done the same thing to two of them and it worked great.

[antique diver]

I turned some brass bar stock to the outside diameter of the mouthpiece body, cut it to about 0.125" thick (not critical), then added a few holes. Figuring that most of the air would be coming through the inner hose, I didn't worry about providing larger holes. These are just to provide the initial vacuum on the diaphragm to get the air flowing, but I think that I will go back and mill out the spaces between the holes when I run out of other projects. That might make the cracking effort a little easier, but not really sure if that will make much difference until I try it.

The rubber valve was just a standard ehaust valve, picked for its diameter, then punched the center to fit over the mp tube. Note in the photo that I added an oring or two on the tube first to help keep the rubber valve in place against the valve body. I obtained some small diameter green Oxygen hose from the local welding supply house to replace the missing original. This is a very interesting and unique regulator, but not my favorite for everyday diving. I think I would see a significant performance improvement by adding the new softer VDH diaphragm that has worked wonders in my other regs.

[gj1963]

Thank you kindly for the information. I will work at making the part soon. Then to find some good replacement green hose as close to original as possible. The reg does have one of the new diaphragms. I certainly don't anticipate it being the greatest breather ever, but do want to get it to work in its original configuration.

[Ron]

I run mine with just the plate for the exhaust valve in it. I find that it runs much better without the exhaust valve in it. The regulator needs the restriction of the metal plate, but it doesn't need the exhaust valve IMO. Mine runs great.

[antique diver]

I run mine with just the plate for the exhaust valve in it. I find that it runs much better without the exhaust valve in it. The regulator needs the restriction of the metal plate, but it doesn't need the exhaust valve IMO. Mine runs great.

Ron, you mentioned the restriction of the plate being necessary. Is that needed to control the venturi? (I have never tried mine without the plate). I think I may need to open the holes up some on mine to get a little better flow.

I'm glad to see you mention that it performs better without the rubber valve, and I am assuming that you meant the inlet side. I was beginning to think that I was the only one that felt that way. Do you dive any other of your DH regs without the mouthpiece inlet valve?