If it's permanent in nature it's gotta have a CoC. That's what the Groot Baas at the Department of Labour mandated.
Like all things legal, there's a whole quagmire of information, misinformation, FUD, fear-mongering and Trump style fake-news out there.
If we peel back the layers, there really are two areas of focus in the law that we can consider first principals:
Obviously there is a ton of other compliance regulations that need to be met before an installation can be considered compliant, but it is incumbent on the installer rather than the consumer to be aware of these.
You as the consumer need to be confident that your appliance you are installing is registered as a compliant tested appliance in SA. And you may need to get involved in the installation process when it comes to the location of the bottles. Pretty much everything else is business as usual.
Your faithful old skottel braai you slap together on a fishing trip to make your breakfast-grease-up doesn't. Pretty much everything else does.
No, the bottles inform what constitutes a single installation, the number of appliances connected to the same line are not significant. If you have two banks of bottles at a single premises, you will need two CoCs.
The regulations informing the Coc are reviewed every 3 years, but the compliance certificate does not expire per se. If you want to transfer property the conveyancers will almost definitely want a new CoC issued. Insurance has also started taking a harder line on CoC requirements.
So, the Department of Labour (DOL) is ultimately responsible for registering qualifications. They have mandated the SAQCC with getting the job done. To issue a CoC you need to be registered on the SAQCC database which means you've passed a quiz and shown you know what you are doing.
Ask your neighbour.
Is it permanent?
Yep, internal installations are allowed. Up to 9Kg's in a flat, up to 19Kg's in a house. You're gonna need to forfeit a whole cupboard to the bottles though, so you may wanna check with the kitchen boss.