[Dentlord]

I should start having them fill it without the top as well, I get the feeling I would get a lot more ln2 per fill if I did.

[Buckeye]

Thats how they fill mine. I take off the top and they just drop a hose into it and away it goes.

Like was said before, mine is a low pressure Dewar so when its full I generally have to let it sit over night before I can start getting a good flow of liquid out of it. I have seen a way to pressure the tank tho., but it requires a few fitting and a tank of LN gas to do it.

My 50L has never vented, but the 160L's low pressure Dewars I have had vented a lot. 230L high pressure one vented very little.