low-pressure cutoff valves to prevent end of tank dump

[chris_todd]

I hope those of you who are more experienced with CO2 can help me. I've ordered the following regulator from www.beveragefactory.com:
http://www.beveragefactory.com/draftbee ... ator.shtml

This regulator has an "Integral PRV Safety pressure relief valve releases at 55-65 PSI " - that is not the same as a low-pressure cutoff valve, is it?

Would I still need to add the following valve from clippard to prevent end of tank dumps?
http://www.clippard.com/store/display_d ... u=MAR-1P-3

And could someone explain again what happens at end of tank dump? I'm confused...I thought that when the pressure in the tank decreases below a certain point (because most of the CO2 has been used), all the liquid CO2 evaporates at once, and rushes out of the tank. So wouldn't that mean you'd need a high-pressure safety valve (as appears to be integrated into the regulator I bought), instead of a low pressure cutoff valve?

[jcali10]

From what I read, if you use a low pressure regulator like the one Clippard sells, you have to set your CO2 tank output pressure below the low press reg pressure. So if your tank output is 10 psi, your low pressure regulator would need to be higher. Otherwise it would just vent off the excess gas. If say your tank is set to 30 psi and your low press reg was set to 15 psi, venting will occurr.

I could be wrong, but that is the way I understand it. I have some experience, not much. I hope others respond too.

[jcali10]

CO2, all the time it is in a liquid form, it will be at a constant pressure. When it turns from liquid to gas the pressure will change.

To know how much CO2 you have left you can weigh your tank when full. The tare weight should be stamped on your tank.