АлександрД
Contributor
I`m always try to disconnect my regulators from tank valves under pressure! 
Sure, tank valve should be closed at this moment.
How and why I do it:
After closing tank valve I make pressure drop (checking by SPG) till 30-40 bar, by pressing purge button on the second stage.
Then (I using DIN only) slowly turning DIN nut (NOT regulator body!), until it starts to "psssssst", waiting, and than easy disconnecting regulator from tank valve.
With Yoke it much easy to do.
Than I check O-ring, and when it came out from groove, putting it back.
At this moment we have:
Closed tank.
Detached regulator.
AND! Pressure inside regulator and hoses, equal to IP.
Then I SLOWLY pressing purge button.
In one moment regulator valve will be opened, and air starts to going out from HP connector through regulator filter.
This allow to clean filter by air, containing inside hoses.
This allow to clean filter from rust particles from the tank and from any water drops, that could stay inside connector.
I`m doing it ALWAYS
Only one bad thing could be there - you can lost or dammage your O-ring on the HP connector. You just need to be care about it.
No any other problems could be here.
P.S. you can put your wet hand before HP hole when you doing it, and you will see, how many rust you have on the filter.
Try to do it, and you will be amazed.
Sure, tank valve should be closed at this moment.
How and why I do it:
After closing tank valve I make pressure drop (checking by SPG) till 30-40 bar, by pressing purge button on the second stage.
Then (I using DIN only) slowly turning DIN nut (NOT regulator body!), until it starts to "psssssst", waiting, and than easy disconnecting regulator from tank valve.
With Yoke it much easy to do.
Than I check O-ring, and when it came out from groove, putting it back.
At this moment we have:
Closed tank.
Detached regulator.
AND! Pressure inside regulator and hoses, equal to IP.
Then I SLOWLY pressing purge button.
In one moment regulator valve will be opened, and air starts to going out from HP connector through regulator filter.
This allow to clean filter by air, containing inside hoses.
This allow to clean filter from rust particles from the tank and from any water drops, that could stay inside connector.
I`m doing it ALWAYS
Only one bad thing could be there - you can lost or dammage your O-ring on the HP connector. You just need to be care about it.
No any other problems could be here.
P.S. you can put your wet hand before HP hole when you doing it, and you will see, how many rust you have on the filter.
Try to do it, and you will be amazed.
