It is definitely ok for the tank outside and run a long hose inside.

If you want a more secure, safe and last long, run a flexible copper pipe. Than short hose for both side. It is easy to change the hose next time.

In my case, the burglars climb in and carried away the tank. Can sell off for RM50.

That is 1 in a million chance. Ha......

Putting outside is more safe than inside. Gas leak won't kill you. Chance of explode is less if caught fire.

After many yrs, it will clog also. But clog the valve O ring and stuck the nozzle. GI is using because it cheaper.

Doing a lot using GI pipe as gas piping. Even for bigger gas pipe which using flange to joint.

The best is still the copper pipe. And for easy work, just use the flexible copper pipe. Cause the diameter is just fit nice to the hose. And tighten with the hose clip.

How long it last very much depend on the vapour content in the pipe. Who will open out the GI pipe and check. Most of the people don't no and thaught the burner have problem when the

1) turn the knob higher to get more frame
2) yellow frame
3) totally no frame.

But this is very easy DIY. Just unscrew the nozzle, knock the nozzle till the dirt out. If too stubborn use a needle or what ever match the nozzle size hole, poke into it. But don't poke too hard till the hole big. Some of this nozzle is make of copper.

For o ring, change it, oil it and clean the internal.

I not sure here. But what I experience in spore HDB is using GI pipe.

For factory yes. Most of it. For bigger size that have big gas tank in factory which need bigger pipe, Steel pipe is use. Joint is weld with flange and screw and nut is use.

Copper is use when near to burner and around it.

Any copper size 1/8 is ok. The gas hose internal diameter is just nice to fix in. Use hose clip to secure it.

Don't forget to test with soap water and pressure it for sometime for leaking test.