I figure the manufacturer of the equiptment should have the
athoritative say rather than just individual opinion.
Taken directly from the "Saftey and Operating Instructions" manual
for single and dual stage regulators which came with my most recent
(March of this year) regulator purchase ( put out by Victor
Equiptment Company) I quote the following instructions:
WHEN YOU ARE FINISHED USING THE REGULATOR
Close the cylinder valve.
Open the valve on the downstream equiotment. This drains all the
pressure from the system.
Close the valve on the downstream equiptment.
Turn the adjusting screw counterclockwise (on the regulator) to
release tension on the adjusting spring.
Check the guages after a few minutes for verification that the
cylinder valve is closed completely."
I've seen too many "opinion" posts on this subject that are
incorrect. In this case, if the tension on the regulator's adjusting
spring is not released after use and the lines drain before
subsequent use, the next time the cylinder is opened the full
pressure of the take will hit the regulator's diaphram with full
force and (especially in the case of the oxygen regulator)
potentially blowing the face of the regulator apart and causing
serious bodily injury.