Moisture effects pilot lights and other probs. Can save cost of purging. Put anhydrous methanol into container to eat water, and bleed off several times. Two ways to fill cylinders. Also, can fill by weight.
Propane goes to regulator via hoses.
Check them for cracking. Check hoses for dry cracking as well. Don't use teflon tape or lubricant on threads. Two stage regulators provide margin of safety. Autochangeover lets you open both tanks, point to the primary tank which will be used up first.