Compressed gas is stored at an extremely high pressure, so yes unfortunately you do need a regulator. I'm waiting on mine coming tomorrow. They're expensive but considering what they're for,
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I just tested a connection straight-to-hose with a 2L nitrogen cylinder earlier today with bluetac, micropore tape and duct tape wrapped as tight and secure as I could get it. When I very very gently opened the valve on the canister, the whole hose and all the stuff I'd secured it with popped right off and flew across the room with a sound like a very loud champagne cork being poppe