Is the Daycor Extreme a piston or diaphram reg?

[a4lod]

Please respond. Thanks.

 

[rescuediver009]

Its a piston, and a very old one at that. It uses a very small piston encased in the module.
Here is the first stage:
http://www.connect.fi/tekniikka/regut/dacor/extreme_ice_quantum_enduro_mechanical_2ndstage.jpg
And a closer look at the module:
http://www.connect.fi/tekniikka/regut/dacor/module_first_stage.jpg

Geez I am good (just kidding)

 

[DA Aquamaster]

I have always regarded Dacor's module first stages like the Extreme and Quantum as being a variant of a diaphragm first stage. They utilize an upstream HP seat and a pushrod just like a more conventional diaphragm first stage. They do technically use an o-ring sealed "piston", but it functions like a diaphragm instead of a conventional piston in that it just transmits pressure and moves the pushrod to lift the HP seat assembly off the orifice.

In my opinion the upstream location of the HP seat carrier and balance chamber is a defining characteristic of a dipahragm reg. The fact that the "diaphragm" is actually an o-ring sealed chunk of plastic moving a short distance in a cylinder rather than a flexible piece of rubber is a moot point.

So I guess now we need a third tech to break the tie.

 

[rescuediver009]

My bad, just realized that I sent you the wrong link of the whole first stage.
http://www.connect.fi/tekniikka/regut/dacor/extreme_first_stage.jpg

I think that this thing was sort of a piston or diaphragm alternative prototype thing that never made it due tothe complexity. I am sure that you conquer just by looking at the blowup if you have not seen in one before. I didn't realize that the ring was not attached to the pushrod. I kinda agree with DA in that it is not a piston persay, but it has no more a diaphragm than a piston. Like I said 'weird hybrid thing that never made it'.

 

[bottomrunner]

hi
it is a direct acting piston.
it has an enviromental chamber covered by a diaphram on each side. with a push rod under second diaphram to the piston.
i had a extreme plus.
and learned very quickly to do my own service on this one.
here is a story to learn from.
the extreme was my first reg that i had bought new.
it had a full year of diving.
and was ready to have it's annual service.
i also have a healthways sonic that i used on my pony bottle.
both went in to shop to have service.
picked them up a week later.
got into the water, it was a cold february day, water temp was 34f.
everything went well until i got to 60 feet.
then my primary second stage failed closed, !YES CLOSED!.
looked at my pressure gauge it showed 2500 psi.
keep in mind i had to exhaust breath to find out that reg would not give me any more.
grabbed my octo. and got a breath and a half off of it and it failed closed as well.
pressure gauge still reads 2500 psi.
by now i have my knife out, hammering on my tank to get buddy's attention.
who is 40 feet away by now, and hears nothing.
i grabbed my pony reg, put it into my mouth, crossed my fingers and took my first breath.
that resulted in a freeflow.
too much air is better than none.
my so called buddy surfaced 3 minutes later when he noticed that i was not there.
something was not right, i was taught in the basic course that scuba regs were fail safe. resulting in a freeflow not shut down.
so i went looking for a second opinion.
and found a reg course.
so when i started to disassemble my reg, i noticed that the manifactures seal, a dab of red paint, was not broken.
so the reg was never opened.
they(the shop) had wiped the hoses to make then look new, and charged me 50 bucks for each reg.
after i opened the extreme i found the problem.
the o ring on the piston, after a hard year of diving, had lost its lubricant.
the piston slides from the high side to the low side of the pressure as you breath off of it.
it was a 50/50 chance where the piston was going to seize when the lubricant wore off.
after i did the service myself, i got back into the water in 33f. temp.
got to 80 feet, bottom time was 25 min. and had no problems.
every body else who was there with all makes of regs lasted about 10 min. before they free flowed because of the cold water.
when i got out of the water and looked at my first stage.
it was incassed in a 1/4 inch of ice
moral of my story!
good reg when properly serviced. however requires more T.L.C.

 

[oxyhacker]

It's neither, really - it's a hybrid, a "piston assisted diaphragm" according to Dacor (or is it Diaphragm assisted piston?).

It's also overbalanced - the IP increases with depth, approximately 2 psi per 25'. Dacor has a gadget that allowed pressurizing the end to test the boost function when it was serviced, but I've never actually seen anyone use one.

 

[rescuediver009]

It's neither, really - it's a hybrid, a "piston assisted diaphragm" according to Dacor (or is it Diaphragm assisted piston?).

I would say piston (if that is what you are going to call the metal moving bit) assisted diaphragm as the piston is the primary device, that is supplimented by the diaphragm.

OK now i think that we are getting into the real who cares stuff.