Gas Valve identification

[rodisi]

Hello forumers. My first post before my first attempt at MIG welding.
I'm just about to go out and replenish my gas bottle and already a couple of questions have come up
1) Does one replace the gasket between bottle and valve/meter assembly every time the bottle is changed?
2) My meter/valve assembly has two valves, a large one at the bottom and a smaller one on the side. Any explanations please?

 

[wyn]

I'm not sure on the gasket.

The larger valve looks like it controls the pressure from the gas bottle.

The smaller valve looks like it could adjust the flow. Does the gauge on the right read in lpm?

 

[gordon stephenson]

Looks like a Co2 type regulator, Examine the gasket each time and if it's not damaged in any way use it again.

 

[rodisi]

Yes, it does read lpm.

 

[wyn]

Yes, it does read lpm.

The smaller side valve must be a flow meter.