looking for opinions for connecting gauges with minimum refrigerant loss, with lines with no ball valves.
Should we shut down system, then screw in discharge service valve to connect discharge line, then should suction service valve be shut before connecting suction line.
I have been tought to just screw them on quickly and let it spray, but I am more aware of effects now.
Explanations would be greatly appreaciated. Will I be better buying new lines with ball valves, etc.

Nev