Vintage Double Hose

2airishuman wrote:Hello everyone

I have a number of Conshelf regs that I dive, and I recently obtained the parts to add the "supreme" environmental seal to two of them. One set of parts is the "external fine adjust" (EFA) and the other is not. I am trying to decide how to set these up and what parts to replace.

1) Should the secondary diaphragm be replaced at every service interval?
Yes...the sealing edge tears very easy after it has been in place for a long time and is difficult to seal again reliably. I won't service one unless I have new one to replace it with.....BTW, Herman makes a very nice tool for removing the diaphragm retaining ring which is easy to damage.
2) Should I keep the EFA setup or just switch it back to a standard secondary diaphragm?
The EFA is nice if you can get EFA diaphragms which are more difficult to come by. The NON EFA are much more common.
3) Can I convert a standard secondary diaphragm to EFA by just punching a hole in it?
The hole you punch would have to be very precise and even with that I believe the EFA diaphragm is reinforced where the adjustment screw penetrates the diaphragm.

Also wondering what the rationale is for dialing back the IP from 140 on a standard conshelf to 120 on the supreme.
I set them all at 135 +/- 5

Advice welcome!