Posted By Mitch
Be cheaper to buy one if you look into it.

Posted By MP
The purpose of the cage is mainly to stop unauthorsed persons tampering with the cylinders.

Just a substantial angle iron frame with strong 1 inch mesh welded in place will probably do.

Lockable with good padlock, Consider double doors to allow room for flt if required.

Make it bigh enough to allow plenty of room for manouvering cylinders, physically large enough to accomodaye anticipated stocks.

Fulls one end - empties the other
Flams and oxygen seperated as much as possible with the space in between used for inerts like N2 and Ar

If you are storing LPG then make sure it is 3.0 metres away from other gases and boundaries. Otherwise 1.0 metre from boundaries where space on site may be at a premium will be OK for non LPG.

Consider lighting arrangements, signage and site it away from combustibles, skips and diesel tanks, etc.