Trident

[redacted]

I bought a magnehelic and used it a couple times just to put some numbers with my sink test and feels right standards. It has not been out of the tool box in over a year now. I adjust my 2nds to withing 30 degrees of leaking. I then take a few breaths to see that it feel good and put it in the sink to estimate cracking pressure. With my adjustable 2nds I sometimes get a bit more agressive and leave them at the leaking end of the 30 degree bracket where less than one turn of the adjustment knob stops the leak. I seem to ba able to get less than 1 inch cracking pressure on all my Barrel poppet and coaxial 2nds. The few classic downstream design 2nds I still use tend to end up a little over 1" cracking pressure.

 

[Zung]

I don't bother with measuring the cracking effort. I just get it as low as I am confident that the reg will be stable in the water...

Interestingly, there seems to be a pattern: out of the dozen or so G250/156/109 I have, and using the 1 hour past sealing method:

2 rogue ones: 20mm/.8 in.
All the rest: 22mm/.9 in.

Pretty cool machining!