Never seen this gas fitting before? Safe for DIY?

[Al85]

I am a DIYer. I've done lots of wet plumbing in house but never gas for obvious reasons. I just want to change over an old for new gas cooker... I was expecting to see some form of isolator valve when I pulled back cooker, but instead I see this.

1) What is it?
2) Is it an isolator or will I need to shut off the gas at the mains to swap over?
3) Is there a way for me to safely change cookers over without shelling out for a gas engineer?

I see a nut on the top, but dont want to turn it and risk knackering it when I don't know the piece of kit.

Thanks
Al

 

[big-all]

turn gas off then you just push up the hose and turn the knurled ring with your hand

 

[stem]

They are very common. Designed to allow a cooker to be connected without tools, using a bayonet connection. Plug and twist like the old light bulbs. Probably best to get a gas safe engineer to install it though, he will have the equipment to check for leaks.

 

[Dan Robinson]

And who's fitting the hose to the new cooker?

If you were expecting a valve, then you were expecting to disconnect something.

How is that "not touching gas for obvious reasons"?

Ffs.

 

[denso13]

You can disconnect the old cooker yourself using the bayonet fitting. However, I have seen more than one not reseal properly and leak. I would get someone in to disconnect and reconnect the new one at the same time.