Food for thought

[captain]

When rebuilding diaphragm 1st stage regulators I always take several days to finalize the IP setting, here is why.
Ever look closely at a used HP diaphragm, you see the impression made by the spring pad on one side and the pin support pad on the other. Over time the diaphragm becomes compressed and molded by the spring pressure. I have measured the compressed and
un-compressed areas of the diaphragm and find a .015" to .020" difference in thickness.
If you set the IP and forget it the diaphragm will slowly compress over a period of days. This will caused the spring to be sightly unloaded and result in the IP decreasing over time.
The IP adjuster screw moves .010" in or out with each flat or 1/6th of a turn and after several days it may require turning the adjuster nut one to two flats in to regain the wanted IP.
Set the IP and walk away from it for 3 or 4 days then come back and check it and reset if necessary.

[Vintagediver]

Thanks Captain! That's a very good point; one I would never have thought of, and I'm sure many others wouldn't either. I'll be sure to keep this in mind when I'm working on my regs. Terry