Gas Trains Simplified - The Boiling Point 

We used to use some tubing, a bucket with some water to check for leaking valves. Especially the blocking valve

The traditional valve setup that was shown had a regulator upstream of the valves meaning that if installed in the same situation that the gas pressure applied to the valves would be lower. A reason why the Siemens valve installation as shown can be a lot smaller than the traditional setup shown is that the gas pressure to the valves would be higher, therefore you can get the same gas flow rate through a smaller valve.

Good info folks! Do you guys ever preheat your nat gas to knockoff any liquid before you put into the boiler?

Need some information on piping gas train

Thanks!

I didn't pick up what the gas train is connected to? A water boiler? What is the overall purpose?