Hello
May 29, 2024 at 5:29 pm Fred posted a drawing Figure 1 Regulator in open position .
This drawing shows that the pipe part of the eyelet ist used for reinforce the plastic seat
in the area under the Oring groove . The flange part of the eyelet is nessesary because otherwise
it could move into the piston .
The hole in the seat and eylet is nessesary to release backpressure in the case of an Oring failure .
What i gues is that this design has a problem in relation of certain conditions of Oring failure ,
tank pressure and tolerances of seat parts . Worst case may be the following :
1.) The Oring failed badly .
2.)tank pressure goes between the backside of the plastic seat and the flange of the eyelet .
3.)The same tank pressure goes between the backside of the eyelet and the main body .
Because the backside of the eyelet is vented to the IP there will be only a littel more than IP pressure .
The tank pressure between the plastic seat and the front side of the flange is not vented adequately .
Here the pressure is much higher than on the vented backside of the eyelet .
The eyelet is pressed to the main body and dont move awaiy from the main body . There isn't much air relased .
On the pipe part of the eyelet there is no gasket to the plastic seat , but if the tolerances between both parts are
tight and the tank pressure from outside seat is exposed to a greater area both parts are nearly sealed .
At least there is no adequate ventilation possibel .
Simplyfied we have the situation : Front side and backside plastic seat the same pressure
The front side has the area : area seat - area outside piston : Backside : area seat - outside area eyelet pipe
Because the area of the backside is greater the force is greater and the plastic seat is pressed to the piston .
If the piston moved to the left the plastic seat do the same . The only air the diver can breath is the leak air .
Greetings Rainer