Fire doors

Maintenance

The flat I am renovating has internal fire doors, but the previous owner has taken out the bolt & chain things that makes the doors close. I was thinking I'd have to replace them all but that seems expensive; do they have to include the door closing mechanism as long as the door is the right spec?

Also the flat is in a purpose built block, so do I have to provide a fire extinguisher in the flat? I tried to read the fire advice on this website but I must admit I didn't understand it all!