DA/RAM Hybrid Question

[Creed]

Several people have reported recently getting DA/RAM hybrids. What exactly are these people doing(those selling such regulators, that is)? Are they simply replacing DAAM seats with RAM/Conshelf seats? Or is it something else?

What is it that is incompatible between RAMs and DAAMs? I've looked at diagrams of a RAM, and it looks like the main difference is the seat and the spring block. Is there some subtle difference I am missing, or will a DAAM nozzle with a Conshelf seat and spring block work? Luis, what am I missing?

[Creed]

To test this, I rebuilt a DAAM nozzle using a Conshelf seat, spring block, a filter and a clip. I put it on two tanks: 2200psi and 500psi. I saw no difference in the two.

[Nemrod]

They really are not the same, the nozzle of the DA is shorter and the mechanism is not balanced, the RAM is balanced. I don't know exactly what ypour doing but installation of a mix of parts into a nozzle could be dangerous and unpredictable. I had a DA that had RAM parts stuffed into it and it breathed fine all the way down to 1,000 psi where it shut of cold as a stone. They are different and a close observation of the parts in the diagrams reveals what appear to be subtle differences, they are not all that subtle in result.

Nemrod

[luis]

My experience and what I have heard from others is that there is not such thing as a well functioning RAM-DAAM hybrid. Forgetting about the label, you either have a RAM or a DA. From what I have heard, attempts to mix the parts have failed.

The difference between the two is only the first stage and if they are replaced, the complete first stage has to be replaced. The first stage internal parts are not interchangeable.

The RAM nozzle is 1/10 inch longer than the DA and it had to be done that way to accommodate the spring block and the potential extra travel of the seat.

The spring block in the DA is just that, a stationary spring guide, nothing else.

In the RAM the spring block is the low pressure balancing chamber for the seat. It is also not stationary. It is floating between two springs to accommodate the extra travel allowed to the seat.

Other balanced diaphragm regulators do not use a floating spring block, but they then would require a deeper balancing chamber and perhaps longer stem on the back of the seat, in order to allow a stroke long enough for improved air flow.

In the case of the RAM the seat stroke was accomplished by using what can be called as a telescoping mechanism.

The springs on both regulators are also probably different spring constants, but perhaps in this application it may not be very critical. I am not sure.

Putting a RAM seat and spring block/ balancing chamber in a DA nozzle without the rear spring, IMHO, is a bad idea. It may seem like it works, but I am almost positive that the seat will bottom out and in the best case it will restrict the flow rate, worst case it could possibly jam.

I have made drawings of the RAM nozzle, the seat and the push pin. When I have a chance I will take dimension and draw the RAM spring block / balancing chamber.

Maybe when I get really bored, I will do the same for the DAAM. Then we can compare the two.

[Bryan]

POST FROM A FEW MONTHS AGO

http://www.vintagedoublehose.com/forum/ ... hlight=ram

[Robohips77]

You all may already know this but some pics and info are on Dan's site about this topic. May be helpful info. Still looking for a RAM nozzle. Robohips

[Creed]

Luis,
Thanks. I suspected that the .1" depth difference was the key(I have a copy of your drawings to compare with my own measurements from the DAAM nozzle). To make the parts fit, I left off the 2nd spring, and used the thinnest filter I had. Given the fact that my nozzle seemed to work last night, I can see how someone could put one of these together and assume it would work fine.

I guess I should have prefaced this thread by noting that I have no intention of trying to dive such a hybrid. This particular regulator is destined to get a Phoenix nozzle anyway. My curiosity was piqued by several people reporting that they are getting hybrids like this off of ebay. I knew that it would fail(I remembered James' report on his problems with this from way back when), I just wanted to know why. Thanks for the write up, guys.

[Bryan]

More info......Just ask Nemrod how well putting RAM guts in a DA nozzle works!

[Creed]

More info......Just ask Nemrod how well putting RAM guts in a DA nozzle works!

Oh, I remember his report, and I have no desire to repeat the effect!

I simply wanted to know WHY it didn't work.

[luis]

Thanks Bryan for the pictures.
Great pictures.

IMO this could be another thread that maybe belongs in the "Tech Tips and Downloads Section".

The pictures and info should always be helpful.

[Bryan]

I will make another one in that section. Good Idea Luis.

[WD8CDH]

Just to clarify things, will a RAM nozzle and guts fit and work properly in a DA body?

Thanks

[Bryan]

Not if you want to use it for diving.....Just ask Nemrod about the his regulator that was rebuilt by one of those expert and mysterious "Old Navy" guys.....
I covered this a bit in the 2nd video I posted as well.

[luis]

Just to clarify things, will a RAM nozzle and guts fit and work properly in a DA body?

Thanks

You can not replace just part of the assembly, but if you are referring about replacing the complete first stage body with all its appropriate internal parts the answer is yes.

The only difference between an Aqua Master and a Royal Aqua Master is the first stage. But, the complete first stage has to be replaced as a unit, including the push pin.

That is why when you replace the first stage assembly with a Phoenix first stage you no longer have a DA Aqua Master (no mater what the label reads) you now have a Royal Aqua Master or more accurately a Phoenix Royal Aqua Master.


Does this answer your question?

[Creed]

Just to clarify things, will a RAM nozzle and guts fit and work properly in a DA body?

Thanks

EDIT: Luis gave a better explanation than me, do I deleted mine.