Installing Large Diaphragm

[ScoobieDooo]

In speaking with Captain from this forum last night (thanks much Captain - it was a pleasure chatting with you) - you said something that just occurred to me...

You said "In installing he large diaphragm make sure the little tabs are aligned with the horseshoe."

That’s something I never paid attention to before when rebuilding my DA. Was there a 'certain way' that one must install the diaphragm into the box to 'line it up' with the horseshoe? I was just putting mine in wit no real accordance to anything.

Is that incorrect?

????

 

[ScoobieDooo]

See the enclosed pic showing the tabs...

 

[Nemrod]

Scoobie, remember when I mentioned that the manuals leave out all the little things your just supposed to know--well--guess what---this is one of them!!!!!!

Yes, the tabs must be specifically oriented to the horsehoe levers or the regulator--WILL NOT--preform correctly. It will breath but -very- poorely. You must carefully align the tabs so that the center of the tabs rides on the center of the levers. This is important. One of the DAs I have came with the diaphram incorrectly installed and it was so apparent upon attempting to use the regulator. Further, the lever height must be adjusted per the manual.
If you did not have the tabs aligned the horseshoe lever would not be depressed fully and airflow would be severely restricted. Like I said, just like the manuals I work from at my job as an aircraft mechanic, the basic stuff is not in the manuals, your supposed to know it already. This little item is not in the manual I have.
Not only that but not all diaphrams even have the tabs. The DA and Royal Aquamasters must use the diaphram that has the tabs. The Mistral uses a diaphram with no tabs or the tabs bent over.
Further, one of the three "nozzles" on the second stage "nut" must point into the intake hose when locked with the horseshoe feet.
When bending the tabs (not the diaphram tabs) on the feet that hold the horsehoe lever suspended one must be sure not to restrict the movement of the horseshoe with the "twist" you give the feet tabs that lock the horsehoe from falling off. It should rock freely yet be secure on the feet.
N

 

[ScoobieDooo]

My diaphragm never had any 'tabs' on it - just one large solid metal 'plate' in the center - NO tabs of any kind...

 

[Danny D]

Mike,

I think this was your problem with your past regulator....maybe thats why it took so much for you to draw a breath... like said below you have to align the tabs on the diaphram with the horseshoe!! Case solved! see like i said the little things you overlook!

 

[ScoobieDooo]

So, let me see if I have this right - the little 'tabs' must rest against the horseshoe lever to work correctly?

 

[Nemrod]

Scoobie, your wording is not correct. The diaphram must be positioned so that when the diaphram is depressed by ambient pressure the tabs will contact the horseshoe levers. The alignment is perfect when the center of the tab will contact the center of the horseshoe levers feet. When the diaphram is relaxed there may be a small gap between it and the horsehoe lever. The amount of this gap is something I am still learning on and really to some degree depends on the condition of the diaphram. The lever position/height is pretty much fixed by the manual. Another thing I noted on one of mine was that the horseshoe lever was not equal on each side. One side was higher than the other, I bent the lever to be equal. N

 

[ScoobieDooo]

Interesting...thanks.